Title of Invention	"CARBON NANOTUBE AND NANOPARTICLE COATED CARBON FIBER REINFORCED-POLYMER HYBRID NANOCOMPOSITE WITH IMPORVED THERMOMECHANICAL PROPERTIES AND A PROCESS FOR PREPARATION THEREOF"
Abstract	This invention relates to a nanomaterial and carbon nanotube coated carbon fiber reinforced-polymer hybrid nonocomposite comprising supported material, which is coated with a carbon product comprising carbon nonotubes and nonomaterials, and a polymer matrix material, further according to this invention there is provided a process for preparation of a nanomaterial and carbon nanotube coated carbon fiber rainforced-polymer hybrid nanocomposite comprising the steps of, heating the carbon fiber at a temperature of 100-600°C for a time period of 60-1800 second, coating of catalyst on the surface of carbon fiber followed by heating the catalyst coated carbon fiber in an oven at a temperature of 50-200°C for a period of 100 to 10,000 seconds.

Title of Invention

"CARBON NANOTUBE AND NANOPARTICLE COATED CARBON FIBER REINFORCED-POLYMER HYBRID NANOCOMPOSITE WITH IMPORVED THERMOMECHANICAL PROPERTIES AND A PROCESS FOR PREPARATION THEREOF"

Abstract

This invention relates to a nanomaterial and carbon nanotube coated carbon fiber reinforced-polymer hybrid nonocomposite comprising supported material, which is coated with a carbon product comprising carbon nonotubes and nonomaterials, and a polymer matrix material, further according to this invention there is provided a process for preparation of a nanomaterial and carbon nanotube coated carbon fiber rainforced-polymer hybrid nanocomposite comprising the steps of, heating the carbon fiber at a temperature of 100-600°C for a time period of 60-1800 second, coating of catalyst on the surface of carbon fiber followed by heating the catalyst coated carbon fiber in an oven at a temperature of 50-200°C for a period of 100 to 10,000 seconds.

Full Text	FIELD OF THE INVENTION The present invention relates to carbon nanotube and nanoparticle coated carbon fiber reinforced-polymer hybrid nanocomposite \vith improved thermomechanical properties and a process for preparation thereof. PRIOR ART Various types of composite materials, i.e., polymer matrix including thermoplastic and thermosetting, ceramic matrix, carbon matrix, metal matrix, etc are available for the last 50 years. These composite materials have many advantages over the conventional materials like high strength to weight ratio properties, exceptional temperature and corrosion resistance, high fatigue strength, excellent impact resistance, excellent solvent and wear resistance, very low internal friction coefficient, ability to engineer for use of structural, mechanical and thermal response, very good thermoformability, large-volume production capabilities, no harmful emission during production, etc. These are widely used through out our daily life including construction industries. But very few items are used in aerospace, automobile and medical industries due to the specified mechanical properties, which are not sufficient in these high tech applications. At the same time the inexpensive production techniques suitable for down to earth industries are not available. Conventional carbon nanotube polymer composites are prepared by two ways. One root is the addition of carbon nanotube in the polymer matrix using costly mixer, if the matrix is available in the solid form. Otherwise it is done by sonication if the matrix material is available in liquid form. In both cases the uniform dispersion of carbon nanotube is a major problem. Researchers did not find any substantial improvement in mechanical properties, thermal stability, electrical resistivity, magnetic properties using this technique. Other root is the mixing of carbon nanotube in the precursor of fibers, i.e., pitch in the case of pitch based carbon fiber then extruding the fiber through a spinneret. Researchers have made composites using this fiber and polymer matrix. Again they did not find any substantial improvement in all these properties, i.e., mechanical, thermal stability, electrical resistivity, magnetic, etc due to the uneven distribution of carbon nanotube. Keeping this in mind a process in this invention has been developed where the carbon fiber is coated with carbon nanotubes through out the surface and then hybrid nanocomposites are prepared using this carbon nanotube coated carbon fiber. In this the question of distribution of carbon nanotube does not arise. In this case we find an excellent improvement is found in mechanical properties, electrical resistivity and thermal stability, etc. BACKGROUND OF THE INVENTION Pitch-based carbon fibers, having a highly ordered morphology, are well known in the art. That is, when heated, pitch materials form an isotropic mass. As heating continues, spherical bodies begin to form. The spherical bodies are of an anisotropic liquid crystalline nature as viewed under polarized light. These spheres continue to grow and coalesce until a dense continuous anisotropic phase forms, which phase has been termed the "mesophase." Thus, the mesophase is the intermediate phase or liquid crystalline region between the isotropic pitch and the semi-coke obtainable at higher temperatures. Mesophase pitch is extruded into fibers, oxidatively stabilized, and carbonized at high temperatures to form mesophase pitch-based carbon fibers. As compared to PAN-based carbon fibers, these mesophase pitch-based carbon fibers have a relatively high tensile modulus but a relatively low tensile strength and a relatively low compressive strength. That is, the highly graphitic structure of these polymers is responsible for their high modulus and high thermal conductivity, but also for their low strength. The structured, crystalline morphology that provides for the high tensile modulus also allows for the brittle failure of the fibers caused by the propagation of even minute flaws. In order to reduce the tendency of carbon fibers to fail through flaw propagation as described above, a variety of prior art patents have provided methods for producing such fibers with a less ordered, more random microstructure. To date, these efforts have focused on the method by which the fiber is extruded, including modification of the geometry of the die through which the fiber is extruded, rather than on composition modification. Carbon nanotubes, multilayer tubules by evaporating carbon in an arc discharge were first reported in 1991 by lijima (1). These linear fullerenes are attracting increasing interest as constituents of novel nanoscale materials and device structures. Defect-free nanotubes are expected to have remarkable mechanical, electronic and magnetic properties that will be tunable by varying the diameter, number of concentric shells, and chirality of the tube. Later on in 1993, lijima and Ichihashi (2) and Bethune et al. (3, 4) independently discovered a single-wall nanotube by vaporizing carbon together with a transition metal such as iron or cobalt in an arc generator. These syntheses produced low yields of non-uniform nanotubes mixed with large amounts of soot and metal particles. Subsequently Richard Quo et al. (5) disclose a process for making singlewall nanotubes having diameters of about 1 nm and lengths of several microns. The nanotubes aggregated into "ropes" in which many tubes were held together by van der Waals forces. The nanotubes produced were remarkably uniform in diameter. Significant improvement in yield of 70 to 90% and the 10, 10 configuration (a chain of 10 hexagons around the circumference of the nanotube) was reported by Rao et. al (6) . The product consisted of fibers approximately 10 to 20 nm in diameter and many micrometers long comprising randomly oriented single-wall nanotubes, each nanotube having a diameter of about 1.38 nm. Liu et al. (7) reported single-wall fullerene nanotubes that are converted from nearly endless, highly tangled ropes into short, open-ended pipes that behave as individual macromolecules. Also described therein is the termination of the open ends of the nanotubes with carboxylic acid groups after treatment in acid. This is followed by reaction with SOCb at room temperature to form the corresponding acid chloride. This single wall carbon nanotube has an outstanding strength of ~37GPa, stiffness of -640 GPa, Young's modulus of ~ 2.8 to 3.6 TPa, specific gravity of ~ 1.30, electrical conductivity of ~ 106 S/m, thermal conductivity of ~ 2000 W/mK, specific surface area of 1350 m2/g, etc. Researchers are trying to utilize these outstanding properties through several roots. One group of researchers dispersed carbon nanotube into a wide range of polymeric materials to produce composites with unique properties ranging from high performance engineering materials to additives for accelerating chemical reactions. The dispersion is achieved by either shear mixing using a Haake Polylab unit or Brabender Labstation or by the use of a high energy ultrasonic probe when dispersion into a liquid is required. The polymeric materials are polyamine (8), polyether (8) bisphenol A (9), epoxy (10), poly(m-phenylene vinylene-co-2,5-dioctoxy-pphenylene vinylene (11), polymethylmethacrylate (12, 13), polyimide (14,15), poly(vinylidene fluoride) (16) and poly(vinylpyrrolidone) (16), acrylic polymers (17), fluoropolymers (17), polycarbonates (17), polycyanurates (17), polyesters (17), polysiloxanes (17), polyurethanes (17), polythiophenes (18), polyvinylcarbazole (19), polyimides (20), polysulfonamides (20), polythiophenylenes (20), polyureas (20), polyurethanes (20), elastomers (21), silicones (21), fluorinated polymers (21), polysulfones (22, 23), polyoxyalkylenes (24), etc. Another group of researchers (25-27) mixed carbon nanotube before polymerization of monomer to improve the dispersion of carbon nanotube into polymer matrix. Another group of researchers (28-36) mixed carbon nanotube into the precursor of fiber or polymer and then extrude into fiber for further improvement in dispersion of carbon nanotube into matrix material and to get the best mechanical properties. Another group of researchers wrote few review papers based on the carbon nanotube polymer composites (37-45). Because of their outstanding properties, further progress towards better distribution of carbon nanotube in matrix material is desirable. Keeping this in mind, the present invention is to synthesis carbon nanotube on the surface of carbon fiber to eliminate the problem of uneven distribution of carbon nanotube in the matrix material. This carbon nanotube coated carbon fiber will be used to make a polymer composite material for high tech application. OBJECTS OF THE INVENTION The object of this invention is to provide a carbon nanotube and nanoparticle coated carbon fiber reinforced-polymer hybrid nanocomposite and a process thereof. Another object of the invention is to provide a carbon nanotube and nanoparticle coated carbon fiber reinforced-polymer hybrid nanocomposite and a process thereof for coating on the long carbon fiber having micronsized diameter. Another object of the invention is to provide a carbon nanotube and nanoparticle coated carbon fiber reinforced-polymer hybrid nanocomposite and a process thereof for uniform growth of carbon nanotube on the surface of long carbon fiber Still another object is to provide a carbon nanotube and nanoparticle coated carbon fiber reinforced-polymer hybrid nanocomposite and a process thereof for manufacturing of fiber reinforced polymer hybrid nanocomposites using carbon nanotube coated fiber and polyester resin. The next objective is to provide a carbon nanotube coated carbon fiber reinforced-polymer hybrid nanocomposite and a process thereof to characterize the newly developed fiber reinforced polymer nanocomposites through surface area, scanning electron microscopy, transmission electron microscopy, X-ray diffraction studies, storage modulus, loss modulus, loss tangent and thermal stability in various atmosphere, I-V characteristics, magnetic properties, etc. BRIEF DESCRITPION OF THE ACOMPNAYING DRAWING AND TABLES Further, objects and advantages of this invention will be more apparent from the ensuing description when read in conjunction with the accompanying drawings and wherein: Figure 1 shows a schematic diagram of coating unit Figure 2 shows a Schematic diagram of reactor Figure 3: XRD pattern of as-received carbon fiber, nanoparticles coated carbon fiber, and nanoparticles and carbon iianotubes coated carbon fiber. Figure 4 is a SEM micrograph of as-received carbon fiber at a magnification of 8000X Figure 5 shows EDAX data of as-received carbon fiber at a magnification of 8000X Figure 6 is a SEM micrograph of nanoparticle and carbon nanotube coated carbon fiber at a magnification of 3000X Figure 7 is a SEM micrograph of nanoparticle and carbon nanotube coated carbon fiber at a magnification of 80000X Figure 8 is a TEM micrograph of as-received carbon fiber Figure 9 is a TEM micrograph of nanoparticles and carbon nanotube coated carbon fiber Figure 10 is a TEM micrograph of nanoparticles and carbon nanotube grown on carbon fiber Figure 11 is a SAD pattern of nanoparticles and carbon nanotube grown on carbon fiber Figure 12 is a TEM micrograph of nanoparticles and carbon nanotube grown on carbon fiber Figure 13: TGA curves (D: as received carbon fiber; and O: nanoparticles and carbon nanotubes coated carbon fiber) in nitrogen atmosphere at a heating rate of 10°C/minute Figure 14: Derivative (% weight/minutes.) curves for (Li: as received carbon fiber; and O: nanoparticles and carbon nanotubes coated carbon fiber) in nitrogen atmosphere at a heating rate of 10°C/minute Figure 15: Heat flow curves (D: as received carbon fiber; and A: nanoparticles and carbon nanotubes coated carbon fiber) in nitrogen atmosphere at a heating rate of 10°C/minute Figure 16: TGA curves (D: as-received, carbon fiber; and A: nanoparticles and carbon nanotubes coated carbon fiber) in oxygen atmosphere at a heating rate of 10°C/ minute Figure 17: Derivative (% weight/ minutes.) curves (D: as-received carbon fiber; and A: nanoparticles and carbon nanotubes coated carbon fiber) in oxygen atmosphere at a heating rate of IOC/minute Figure 18: Heat flow curves (D: as-received carbon fiber; and A: nanoparticles and carbon nanotubes coated carbon fiber) in oxygen atmosphere at a heating rate of 10°C/ minute Figure 19: Heat flow vs. time curves (D: as-received carbon fiber; and A: nanoparticles and carbon nanotubes coated carbon fiber) in oxygen atmosphere at a heating rate of 10°C/ minute Figure 2O: Storage modulus vs. temperature curves for (LJ: as-received carbon fiber; and A: nanoparticles and carbon nanotubes coated carbon fiber) hybrid nanocomposites Figure 21: Relative storage modulus vs. temperature curves for (LJ: asreceived carbon liber; and A: nanoparticles and carbon nanotubes coated carbon fiber, coating time 30 minutes) hybrid nanocomposites Figure 22: Loss modulus vs. temperature for (D: as-received carbon fiber; and A: nanoparticles and carbon nanotubes coated carbon fiber) hybrid nanocomposites Figure 23: Relative loss modulus vs. temperature curves for (D: asreceived carbon fiber; and A: nanoparticles and carbon nanotubes coated carbon fiber) hybrid nanocomposites Figure 24: Tan 8 vs. temperature curves for (D: as-received carbon fiber; and A: nanoparticles and carbon nanotubes coated carbon fiber) hybrid Table 3 shows degradation temperature corresponding to peak for asreceived carbon fiber and nanomaterial and carbon nanotube coated carbon fiber in oxygen atmosphere According to this invention there is provided a nanomaterial and carbon nanotube coated carbon fiber reinforced-polymer hybrid nanocomposite comprising supported material, which is coated with a carbon product comprising carbon nanotubes and nanomaterials, and a polymer matrix material. Further according to this invention there is provided a process for preparation of a nanomaterial and carbon nanotube coated carbon fiber reinforced-polymer hybrid nanocomposite comprising the steps of : a. heating the carbon fiber at a temperature of 100-600°C for a time period of 60-1800 second, coating of catalyst on the surface of carbon fiber followed by heating the catalyst coated carbon fiber in an oven at a temperature of 50-200°C for a period of 100 to 10,000 seconds. b. keeping of catalyst coated fabric or fiber loaded quartz boat in the mid zone of a reactor as herein described, - connecting the reactor to a vacuum line to pump down to less than 200 mm Hg incorporation of the gases into the mixing chamber and subsequently in reactor - de-oxygenation of the gases followed by removal of moisture - growth of nanomaterial and carbon nanotubes under different conditions as herein described. c. fabrication of hybrid nanocomposite comprising the steps of: -mixing of curing agent, also known as hardner in a resin, also known as polymer in a ratio of 100:0.2 to 100:5 at a temperature of 10 to 50°C -mixing of accelerator, also known as catalyst with solvent in a mixture of resin and hardner in ratio of 100:0.2 to 100:5 at a temperature of 10 to 50°C -dipping the nanomaterial and carbon nanotube coated fiber in the mixture of resin, hardner and catalyst and keeping in the mould to get a shape of mould known as preform, - loading of the perform in hydraulic press and curing at a pressure of 1 to 10 kg/cm2, and temperature of 25-100°C for a period of The additional features of the invention have been depicted in the dependent claims. DETAILED DESCRITPION OF THE INVENTION According to the present invention a technique has been developed to fabricate fiber reinforced polymer hybrid nanocomposites from carbon nanotube and nanomaterials coated carbon fiber and polyester resin. Further according to this invention: 1. Fiber reinforced polymer hybrid nanocomposite is prepared using nanomaterial coated carbon fiber and polyester resin 2. Various nanomaterials acts as catalyst i.e., cobalt (Co), nickel (Ni), ruthenium (Ru), rhodium (Rh), palladium (Pd), iridium (Ir), platinum (Pt) chromium (Cr), tungsten (W) are tested to grow carbon nanotube on the surface of carbon fiber. 3. Various mixed nanomaterials acts as catalyst i.e., combination of any two following metals, i.e., cobalt (Co), nickel (Ni), ruthenium (Ru), rhodium (Rh), palladium (Pd), iridium (Ir), platinum (Pt) chromium (Cr), tungsten (W) are tested to grow carbon nanotube on the surface of carbon fiber. 4. A high purity low coat process has been developed to coat carbon nanotube on the surface of carbon fiber. 5. Various environments, i.e., nitrogen, hydrogen, acetylene, methane, etc are tested to get a good and uniform coating of nanomaterials and carbon nanotube on the surface of long carbon fiber. 6. Various mixed environments using nitrogen, hydrogen, acetylene, methane, etc are tested to get a good and uniform coating of nanomaterials and carbon nanotube on the surface of long carbon fiber. 7. Various compositions of mixed environments using nitrogen, hydrogen, acetylene, methane, etc are tested to get a good and uniform coating of nanomaterials and carbon nanotube on the surface of long carbon fiber. 8. Different temperatures to crack me thane/acetylene are tested to get a good and uniform coating of nanomaterials and carbon nanotube on the surface of long carbon fiber. 9. Different times to crack methane/acetylene are tested to get a good and uniform coating of nanomaterials and carbon nanotube on the surface of long carbon fiber. 10. A process has been developed to prepare nanomaterials and carbon nanotube coated carbon fiber nanocomposite. The invention also provides compositions used to coat catalyst and carbon nanotube on the surface of carbon fiber. Surface area, scanning electron microscopy, transmission electron microscopy, X-ray diffraction studies, storage modulus, loss modulus, loss tangent and thermal stability in various atmosphere, etc. have been conducted on appropriately designed specimens to characterize the materials. The hybrid nanocomposite is prepared in three steps, which are described below with the help of different embodiments, which are to be taken as example without restricting the scope of the invention to the same. (1) Coating of Catalyst on the Surface of Carbon Fiber/Fabric The preparation and deposition of catalyst on the substrate are critical steps. A uniform and optimum thickness of catalyst is essential to get a niform and good coating of carbon nanotubes through out the surface of carbon fiber/fabric. Embodiment-1 Catalyst is coated on the surface of carbon fiber by dip coating technique using an acidic bath shown in Figure 1. The compositions of bath are given in Table 1. The bath is prepared by first dissolving the required amount of oxidizing agent in de-ionized water and subsequently other chemicals are added in the solution. The mixture is continuously stirred for -30 minutes to ensure the proper mixing of all chemicals. Finally this green colored solution is used in the dip-coating set-up, Figure 1 to deposit catalyst on the surface of carbon fiber/fabric. The coating is produced by the controlled chemical reduction of metallic ions onto a catalytic surface. For the further detail reference may be made to claim 20 and 21. After dipping the carbon fiber in the bath it is placed in an oven at a temperature of 100°C for -20 min. The temperature of electroless nickel solutions is one of the important factors affecting the rate of deposition. The rate of deposition is low at temperatures below 65°C, and increases with an increase in temperature. This is true for almost all the systems. The operating temperature for this study is about 65-75°C. All the elements of group VIb and VIII are applicable to this invention. Embodiment-2 Metal catalyst is prepared by mixing of metal nitrate (for example iron nitrate) and metal carbonate (for example iron carbonate). 50 g of metal nitrate is dissolved in 500 ml of de-ionized water. When metal nitrate is fully dissolved in water, an equal amount of metal carbonate was added in the solution. The resulting brown colored solution is stirred continuously till it turned into a semi solid mass. This semisolid mass is kept in an oven at a temperature of 120°C for -12 hrs to vaporize all water. Then the resulting mass is kept in furnace at 500°C for 8 hrs. After cooling down to room temperature the brown colored mass was ground in an agate mortar. The resulting brown colored powder is used as catalyst to grow carbon nanotubes. The coating of this catalyst on the surface of carbon fiber/fabric is done by spraying the solution of brown colored powder. The solution was prepared by mixing the -10 g of powder in 500 ml of methyl alcohol. It is stirred at room temperature for -30 min. After spraying this solution on carbon fiber the fiber is placed in an oven at a temperature of 100°C for -30 min. For the further details reference may be made to claim 22. (2) Coating of Nanomaterials and Carbon Nanotubes (CNTs) on the Surface of Carbon Fiber Fabric The coating of carbon nanotubes was conducted in a tubular reactor placed horizontally, and the schematic diagram of the experimental setup was shown in Figure 2. This reactor had a quartz tube of 84 cm length with outer diameter of 49 mm and inside diameter of 45 mm. It was constructed in such a way that the carbon fiber/fabric loaded quartz boat could be easily inserted and removed from the reactor. The reactor was heated in a three zone tubular furnace. A proportional temperature controller controls the furnace temperature in each zone. The temperature was kept around 700 to 900°C in the mid zone of furnace to facilitate the decomposition of precursor gases just above the quartz boat. The inlet and outlet temperatures were maintained at 300-600°C. Nitrogen, hydrogen, methane, ethane, propane, carbon dioxide, ethylene and acetylene were used as precursor gases. Each gas has its own function. Acetylene / methane / ethylene / propane / carbondioxide / ethane acts as a source of carbon, hydrogen acts as a reducing gas to reduce the catalytic layer and nitrogen acts as a carrier gas and also provides the inert atmosphere inside the reactor. The catalyst coated carbon fiber/fabric was kept in the middle zone of the reactor. The reactor was connected to a vacuum line and then pumped down to less than 200 mm Hg. The gases entered in the reactor through three different non-return valves. The flow rates of gases were measured by rotometers, as shown in Figure 2. Gases are first deoxygenated by passing them through an alkaline pyrogallol solution and subsequently moisture is removed by passing them through a silica gel bed. The gases were mixed before entering into the reactor. The water circulation arrangement was made at inlet and exit of the reactors tube to keep the temperature at desired level. Water is also used as a coolant in the condenser. Any condensable in the reactor effluent was collected in a liquid collector where as noncondensables were sent to the exit flow, which was recorded by the pressure indicator dial and then vented to the atmosphere. The different conditions used in each run to grow carbon nanotubes. Embodiment- I 140 X 30 mm/mm catalyst coated fabric or catalyst coated carbon fiber having 3 to 300 micrometer in diameter is kept in a quartz boat. The fabric or fiber loaded quartz boat is inserted in a reactor shown in Figure 2. As the reactor is connected to a vacuum line the gas of reactor was pumped down to less than 200 mm Hg to remove oxygen from the reactor, i.e., to make an inert atmosphere. After that nitrogen was inserted in the reactor. When it comes to the atmospheric pressure again it was pumped down to less than 200 mm Hg. This process is continued 10 times till free of oxygen. In the next step the temperature of reactor was increased up to 600°C in an environment of nitrogen. The rate of nitrogen flow was kept constant at 120 ml/min. At this temperature the temperature of reactor is kept constant for 30 minutes to break the coating of catalyst to nanoparticles in nitrogen atmosphere. After 30 minutes of holding time the reactor temperature is raised to 770°C in the same nitrogen atmosphere. When the temperature becomes constant at 770°C, acetylene was allowed to flow at the rate of 25 ml/min along with the flow of nitrogen gas. The reaction was carried out at this temperature for 20 minutes. After 20 minutes of holding time the reactor was allowed to cool to room temperature and samples were taken out from the furnace for characterization of carbon nanotube and fabrication of nanocomposites. Embodiment- 2 All conditions used in embodiment -1 of coating of nariomaterials and carbon nanotubes (CNTs) on the surface of carbon fiber/fabric are same except the growth time and the flow rate of acetylene. Flow rate of acetylene is kept at 25 ml/min. and the growth time is increased up to In this run the growth time is further increased to 30 min. All other conditions are same as embodiment -1 of coating of na.nomaterials and carbon nanotubes (CNTs) on the surface of carbon fiber/fabric. Embodiment -4 In this condition to grow the carbon nanotubes on the surface of carbon fiber/fabric, the hydrogen gas is used as reducing gas to reduce the catalytic layer. Here, first the temperature of reactor is increased up to 600°C in nitrogen atmosphere with a flow rate of 120 ml/min. Then the flow of H2 is started and kept constant at 15 ml/min. for 30 minutes to reduce the catalytic layer. After this the reactor is heated up to 800°C and the flow of acetylene is started and held constant at 25 ml/min. for 25 minutes. At the end of reaction the reactor is allowed to cool to room temperature. After cooling the samples were removed from the furnace for characterization. (3) Fabrication of Polymer Hybrid Nanocomposites: Embodiment -1 The carbon fabric is cut in right shape using the template from nanomaterial and carbon nanotube coated carbon fiber. The matrix used to prepare the hybrid nanocomposites is polyester resin. The weight ratio of polyester resin:catalyst:hardner is 100:2:2. Total number of layers used to prepare the hybrid nanocomposites was 3. The composite was prepared by conventional hand lay up technique. The preform was loaded in hydraulic press. The pressure cycle was 3.5 kg/cm2. The preform was allowed to cure at a temperature of 50°C for 16 hours. The volume fraction of fiber was -45%. After curing the hybrid nanocomposites were removed from hydraulic press and was used for the characterization of volume fraction of fibers, storage modulus, loss modulus, glass transition temperature, etc. Reference may be made to claim 2 for the fabrication of nanocomposite. Embodiment 2 The carbon fabric is cut in right shape using the template from asreceived carbon fabric, i.e., uncoated carbon fabric. All other conditions are same as mentioned in embodiment 1 of fabrication of polymer hybrid nanocomposite. The potentially outstanding mechanical properties of carbon nanotubes (Young's modulus -1.25 TPa, Tensile strength -lOOGPa) will be of little value unless they can be incorporated in a matrix to make a composite material. Composite materials containing carbon fibers are, of course, lready widely used in application ranging from aerospace to sports equipments. In such materials the matrix can be plastic, epoxy, metal or carbon. The incorporation of carbon fiber into matrix not only confers strength and elasticity to the material but also greatly enhances toughness that is its ability to resist cracking. In this context the carbon nanotubes are an ideal candidate for further improvement of all these above properties in high performance composite structures. But the ability to disperse nanotubes into polymer is a major problem for controlling the properties. Nanotubes that are in clumps or agglomerated with other carbonaceous materials create defect and initiate failure. In addition, they limit the efficiency with which nanotubes carry load. This limitation has been illustrated explicitly in both polymer and ceramic matrix composites. In this scenario an attempt is made to grow the carbon nanotube on the surface of carbon fiber that will help to make a very strong composite material in the world. Keeping this in mind the carbon fiber was coated with various catalysts over a period of time, temperature and composition of bath using dip coating shown in Figure 1. Now the catalyst coated carbon fiber was used to grow the nanomaterials and carbon nanotubes on its surface using a special type of reactor shown in Figure 2. During the growth of nanomaterials and carbon nanotube, the temperature, time and volumetric flow rate of carbon, containing gas, inert gas and reducing gas were varied. The carbon fiber, and nanomaterial and carbon nanotube coated carbon fiber were characterized through thermogravimetric analysis over a range of temperature, environment (i.e.oxygen and nitrogen) and heating rate; dynamic mechanical analysis; scanning electron microscopy; transmission electron microscopy and x-ray diffraction studies to find out optimum condition for formation of nanomaterial carbon nanotubes on the surface of carbon fiber. The compositions of coating solution are the major parameter affecting in the coating process of catalyst; however, in addition to this, other parameters like pH, temperature, bath loading factor, and the surface area of the substrate also affect the thickness of coating on the substrate. Four different types of compositions are studied in this work. The compositions of coating solution are summarized in Table 1. The catalyst-coated carbon fibers were characterized using XRD, SEM, TGA and DTA analysis. It was found that the coating was possible for the compositions 3 and 4 while in others (1 and 2) the coating was not possible. The nanomaterials and carbon nanotubes were coated on the surface of carbon fiber using hot furnace. After the coating of nanomaterials and carbon nanotubes on the surface of carbon fibers, XRD analysis was performed on the nanomaterials and carbon nanotubes coated carbon fibers to see the change in XRD pattern of carbon fibers. Figure 3 shows the XRD pattern of carbon fiber before and after the coating of nanomaterials and carbon nanotubes. The XRD pattern of nanomaterials coated carbon fiber is also included, here. The peak, around 20 = 26° is the characteristic peak of carbon fiber due to its graphitic structure. The location and broadness of this peak indicate that carbon fibers have a coke like character. The peak around 20-34° shows nanomaterials (Here it is nickel. Because nickel sulphate and sodium hypophosphite were used as an oxidizing and reducing agent to coat nickel on carbon fiber respectively). Figure 3 also shows that the carbon basal planes of the carbon structure are not changed by naiioscaled coating because not change in the nature of peak corresponding to 20= 26°. The increase in noise is also observed after the growth of carbon nanotubes. But this noise may be because of the high temperature exposure of carbon fiber during the coating of nanomaterials and carbon nanotubes. Surface morphology of as-received carbon fiber, nanomaterials and carbon nano tube-coated carbon fiber has been analyzed through scanning electron microscope (SEM). The micrograph of as-received carbon fiber is shown in Figure 4. The fiber surface is very smooth and there is no pit mark on the surface of carbon fiber. The diameter- of carbon fibers is calculated from this micrograph. It is seen that the diameter of fibers at a magnification of 8000X is varied from 4 to 6 urn. Figure 5 shows EDAX analysis of as received carbon fiber. SEM micrographs of carbon fiber coated with nariomaterials and carbon nanotubes have been shown in Figure 6 at a magnification of 3000. The micrograph shows a good and uniform coating of carbon fiber surface by nanomaterials and carbon nanotubes. To calculate the length and diameter of carbon nanotubes, a single strand of carbon nanotube is carefully chosen from Figure 4 and shown in Figure 7 at a magnification 80000X. The length and diameter of the carbon nanotubes, measured from these micrographs is -15,000 nm and -40 nm respectively. Figure 7 also shows that the carbon nanotube has a helical structure. This helical morphology comes from the anisotropic properties of catalyst particles. These observations are further supported by TEM analysis, which will be discussed in the next section. TEM study gives detailed information about the nanostructure of carbon nanotubes. Figure 8 shows a typical micrograph of as-received carbon fiber. This micrograph has been taken at a voltage of 120 kVA. The diameter calculated from this micrograph confirms the result obtained through SEM measurements. Figure 9 shows a TEM micrograph of carbon nanotube coated carbon fiber. It shows a rough surface as compared to the as-received carbon, fiber micrograph shown in Figure 8 because of the presence of carbon nanotubes on. the surface of carbon fiber. Another micrograph of carbon nanotube coated on the surface of carbon fiber is shown in Figure 10. It shows the bundles of carbon nanotubes. The kinks in the structure of carbon nanotube are also clearly visible in the micrograph. These kinks are may be due to the coiled structure, helical structure or presence of pentagon/ heptagon bonds in the structure of carbon nanotubes. The corresponding selective area diffraction (SAD) pattern is also shown in Figure 11. It shows the crystalline nature of carbon nanotubes. The ring patterns show that the carbon fibers are not only crystalline but. are also somewhat graphitic. The brightest ring corresponds to the (002) reflection of hexagonal graphite. The next continuous ring seen in the diffraction pattern corresponds to the (110) reflection of hexagonal graphite. There is no difference in the intensity for this particular diffracted ring, which suggests that there is no preferred orientation along the a- or b-axes. I t is observed from the micrographs that the nanotubes present near the carbon fiber surface contains more nanoparticles than the ones situated far from the surface i.e. there are more nanoparticles observed at the base of carbon nanotubes. This is may be because of base growth mechanism of carbon nanotubes where the metal nanoparticles remain at the base of growing nanotubes. This can be also observed from the micrographs shown in Figure 12. The diameter and length of carbon nanotubes measured from these micrographs and comes out. to be -40 run and -15,000 nm respectively. This confirms the previous measurements done with the help of SEM micrographs (Figure 4). The rope like structure of bundles of carbon nanotubes can also be observed from these micrographs. The coating of nanomaterials and carbon nanotubes on the surface of carbon fiber is to be carried out at a temperature of 400-1500°C. TGA analysis of as-received carbon fiber, and coated carbon fiber is essential to know the degradation behavior of these fibers with respect to temperature and environment. The thermal analysis was carried out under nitrogen and oxygen environments over a temperature range of 50- 900°C. The degradation behavior of as-received carbon fiber, nanoparticles and carbon nanotubes coated carbon fiber in nitrogen atmosphere is shown in Figure 13. There is a significant decrease in weight loss of carbon fibers observed after coating of nanoparticles and carbon nanotubes on its surface. It is decreased by -14% after the coating of nanoparticles and carbon nanotubes as compared to weight loss of as-received carbon fiber for the given temperature range of 900°C and nitrogen environment. The coated carbon fibers degrade very slowly through out the entire temperature range unlike the as-received carbon libers, which degrades at a faster rate after 300°C. To find out the degradation temperature where the rate of weight loss is maximum, a derivative curve i.e. weight loss with respect, to time was measured and shown in Figure 14. It shows the derivative (% weight/ minutes.) of asreceived carbon fiber, and nanoparticles and carbon nanotubes coated carbon fibers in nitrogen environment. The derivative curves for coated carbon fiber is almost a straight line and no peak is observed in the curves corresponding to these samples because the weight loss is gradual and very less through out the given temperature range of 900°C and environment (Figure 13). The DTA analysis of all these samples i.e. as-received carbon fiber, and nanoparticles and carbon nanotubes coated carbon fiber are shown in Figure 15. The heat flow first increases with an increase of temperature until a plateau is reached, i.e. the temperature of ~407"C for as-received carbon fibers and then starts decreasing on further increasing the temperature up to 900°C. The nature of degradation reaction is endothermic but the peak for the curves corresponding to nanomaterials and carbon nanotubes coated carbon fiber is shifted toward left i.e., ~380°C as compared to the curves corresponding to asreceived carbon fiber. The temperature corresponding to these peaks are given in Table 2. It is also observed from, this Figure 15 that the area enclosed by the curves corresponding to as-received carbon fiber is lower than the area enclosed by the curves corresponding nanomaterials and carbon nanotubes coated carbon fiber which suggests that the heat required by nanoparticles and carbon nanotubes coated carbon fibers is higher than as-received carbon fiber. This is may be because of the presence of nanoparticles and carbon nanotubes on the surface of carbon fiber in these samples. This requires extra heat to degrade these samples which results in larger heat flow for these samples. The1 same nature of heat flow curves indicates that the type of degradation reaction is same. The degradation reaction depends on the environment. To understand the stability of nanomaterials and carbon nanotubes coated carbon fiber, TGA analysis is carried out for as-received carbon fiber and nanoparticles and carbon nanotubes coated carbon fiber in oxygen atmosphere. The results are shown in Figure 16. The thermal stability is more for nanomaterials and carbon nanotubes coated carbon fiber. The starting degradation temperature is found to be ~600°C. The sudden fluctuation in temperature is also found in TGA analysis of nanoparticles and carbon nanotubes coated carbon fibers in oxygen atmosphere as shown in Figure 16. The derivative of weight loss with respect to time as a function of temperature for as-received carbon fiber and nanoparticles and carbon nanotubes coated carbon fiber is shown in Figure 17. The degradation temperature for as-received carbon fiber is observed at ~560°C in oxygen atmosphere. But the degradation temperature for nanoparticles and carbon nanotubes coated carbon fiber is ~700°C. This indicates the higher thermal stability of this coated fiber as compared to as-received carbon fiber sample. The DTA analysis of as-received carbon, fiber, and nanoparticles and carbon nanotubes coated carbon fiber in oxygen environment is shown in Figure 18. It follows the same endotherrnic trend as observed earlier. The peak temperature is tabulated in Table 3. A small secondary peak is also observed iri the heat flow curves. This peak is due to the change in microstructure as shown in weight, loss curves (Figure 16). To analyze this statement the heat flow data is plotted with respect to time and shown in Figure 19. The nature of the peak is same as shown in Figure 18. To evaluate the performance of hybrid nanocomposite the dynamic mechanical analysis was carried out. The analysis was done within a temperature range of 30-170°C and at a frequency of 1 Hz under bending mode. The variation of storage modulus with respect to temperature is shown in Figure 20. A significant improvement is observed in storage modulus for nanoparticles and carbon nanotubes coated carbon fiber hybrid nanocomposite as compared to as-received carbon fiber composites. The storage modulus for nanoparticles and carbon nanotubes coated carbon fiber hybrid nanocomposite found to be increased by -75% at a temperature of 30°C. The storage modulus decreases with an increase in temperature but at any temperature the storage modulus is higher for nanomaterials and carbon nanotubes coated carbon fibers hybrid nanocomposites as compared to as-received carbon fiber composites. Now the improvement in storage modulus is explained with respect to the relative storage modulus. This relative storage modulus is defined as the modulus ratio of coated to as-received carbon fiber. Figure 21 shows the relative storage modulus of nanoparticles and carbon nanotubes coated carbon fiber hybrid nanocomposite with respect, to storage modulus of as-received, carbon fiber. The relative storage modulus increases with increasing temperature through out the temperature range of 90°C for nanomaterials and carbon nanotube coated carbon fiber hybrid nanocomposite respectively. Then it decreases with an increase in temperature. The increase in modulus can be explained by the increase in kinetic energy (G = v k T) where G, v, k and T are modulus, cross link density, Boltzmann's constant and temperature respectively. But the decrease in modulus with respect to temperature is due to the decrease in intermolecular force of attraction in composite materials. In addition to this the decrease of coefficient of friction between molecules decreases the modulus value a higher temperatures. The variation of loss modulus and relative loss modulus with increasing temperature is shown in Figures 22 and 23 respectively. The loss modulus for nanoparticles and carbon nanotubes coated carbon fiber hybrid nanocomposite is higher than the as-received carbon fiber composite at each, temperature. It is also observed that the loss modulus reduces with increasing temperature for nanoparticles and carbon nanotubes coated carbon fiber hybrid nanocomposite and as-received carbon fiber composite. The same nature is also observed in relative loss modulus data for all these composites (Figure 23). Figure 24 shows the variation of Tan 8 with respect to temperature for as-received carbon fiber composite, and nanoparticles and carbon nanotubes coated carbon fiber hybrid nanocomposite. The value of Tan f> first increases with an increase in temperature and then decreases on further increasing the temperature. For as-received carbon fiber the Tan 8 increases up to a temperature of ~80°C and then starts decreasing as temperature is further increased, whereas for nanoparticles and carbon nanotubes coated carbon fiber hybrid nanocomposites it occurs at a temperature of ~65°C. The peak corresponding to this temperature is glass transition temperature (Tg). The glass transition temperature of all these composites has been listed in Table 4. It is observed from the Table 4 that the glass transition temperature of polyester carbon fiber composite deceases after the coating of nanoparticless and carbon nanotubes on the surface of carbon fiber. Main advantages of the Invention; Advantage 1: This is the first time in the world we have prepared hybrid nanocomposites using long carbon fiber coated with nanomaterials i.e. various type of metals, i.e., cobalt (Co), nickel (Ni), ruthenium (Ru), rhodium (Rh), palladium (Pd), iridium (Ir), platinum (Pt) chromium (Cr), tungsten (W); and carbon nanotubes on the surface of carbon fiber and going to report in the literature. Advantage 2: In case of conventional composite materials it is very tough/difficult to disperse the nanomaterials in the matrix. If it is carbon nanotube again it is difficult due to its lightweight. Keeping this in mind we have developed a process where distribution of nanomaterials and carbon nanotube is uniform through out the surface of carbon fiber. This carbon nanotube coated carbon fiber could be used to make any composite materials for structural application. Advantage 3: It is possible to get a uniform coating of nanoma.teria.ls i.e., cobalt (Co), nickel (Ni), ruthenium (Ru), rhodium (Rh), palladium (Pd), iridium (Ir), platinum (Pt) chromium (Cr), tungsten (W) on the surface of individual long carbon fiber in the range of 1 to 80 nm. Advantage 4: Even though it is possible to get a uniform coating of mixed nanomaterials i.e., combination of any two of the following metals, i.e., cobalt (Co), nickel (Ni), ruthenium (Ru), rhodium (Rh), palladium (Pd), iridium (Ir), platinum (Pt) chromium (Cr), tungsten (W) on the surface of individual long carbon fiber in the range of 1 to 80 nm. Advantage 5: It is possible to get a uniform coating of carbon nanotube on the surface of individual long carbon fiber in the density range of 1 to 90%. Advantage 6: It is possible to get a uniform coating of carbon nanotube on the surface of individual long carbon fiber in the density range of 1 to 80%. Advantage 7: The length of carbon nanotubes on the surface of carbon fiber can be varied within the range of 10 to 20,000 nm. Advantage 8: The diameter of carbon nanotubes on the surface of carbon fiber within the range of 1 to 40 nm. Advantage 9: The carbon nanotube grown on the surface of carbon fiber is helical in structure. This helical structure helps to improve the strain at breaking point of composite materials. This is again another breakthrough. Advantage 10: The thermal stability of nanomaterial and carbon nanotube coated carbon fiber has been improved significantly. 1.5% weight loss is observed when the carbon fiber is coated with carbon nanotube in the temperature range of 25 to 900°C in nitrogen atmosphere where as 16% in the uncoated carbon fiber. Advantage 11: The storage modulus of hybrid nanocomposites prepared by carbon nanotube coated carbon fiber at room temperature, i.e., 25°C is improved by 75% with respect to the uncoated carbon fiber. Where as at high temperature, i.e., 150°C the improvement is 300% with respect to the uncoated carbon fiber's composites. Advantage 12: Generally storage modulus decreases with increasing temperature. This is a conventional fact in case of all composite materials. But when the carbon fiber is coated with nanomaterials and carbon nanotube, storage modulus increases with increasing temperatures upto 100°C. Advantage 13: 50% improvement in loss modulus is observed in hybrid nanocomposites when the carbon fiber is coated with carbon nanotube. Advantage 14: 50% improvement in damping is observed in hybrid nanocomposites when the carbon fiber is coated with carbon nanotube. Advantage 15: The glass temperature of hybrid nanocomposite is shifted to the high temperature, ie., from 65 to 85°C when the carbon fiber is coated with carbon nanotube. Advantage 16: This fabrication process of hybrid nanocomposites is an insitu process. As it is insitu process, this technique does not require any mixer, which is very costly equipment in conventional process. Advantage 17: The processing cost is less as it does not require mixture compared to the conventional process. Advantage 18: The new technique has a great potential in the manufacture of fiber reinforced nanocomposites for high tech applications, i.e., aerospace, automobile, etc. This new hybrid nanocomposites has promise for wide range of applications, viz., automobile, aircraft, space craft, sports, etc. ddering the current and future needs it is the interest to initiate a ig research programme in this area to foster the industries to adopt ;r processing routes for manufacturing their products with superior ifications and also introduce new products based on unique ierties of this class of new generation materials. Again due to the lability of various types of high molecular weight polymers, in near re this advanced hybrid materials is likely to increase the production her reinforced plastic components satisfactorily. This will in turn ance the interest of laboratories and industries. Further, fiber forced plastic technology is labor incentive and India is in a much er shape to compete with developed countries main advantage of this invention is that use can be made of the standing mechanical properties of carbon nanotubes i.e. Young's lules of-1.25 TPa, and Tensile strength of -100 GPa in a structural hybrid icomposites. In this invention it does not need to add carbon nanotube during the cation of nanocomposite in the polymer matrix which is much more difficult to disperse in the matrix. In addition to this the carbon nanotube is grown on the surface of carbon fiber, i.e. it is an insitu process. The resulting hybrid nanocomposite shows excellent thermal stability and mechanical properties. It is to be understood that the process of the present invention is susceptible to modification, changes, adaptations by those skilled in the art. Such modifications, changes adaptations are intended to be within, the scope of the present invention which is further set forth under the following claims: WE CLAIM; 1. A nanomaterial and carbon nanotube coated carbon fiber reinforcedpolymer hybrid nanocomposite comprising supported material, which is coated with a carbon product comprising carbon nanotubes and nanomaterials, and a polymer matrix material. 2. A process for preparation of a nanomaterial and carbon nanotube coated carbon fiber reinforced-polymer hybrid nanocomposite comprising the steps of : a. heating the carbon fiber at a temperature of 100-600°C for a time period of 60-1800 second, coating of catalyst on the surface of carbon fiber followed by heating the catalyst coated carbon fiber in an oven at a temperature of 50-200°C for a period of 100 to 10,000 seconds. b. keeping of catalyst coated fabric or fiber loaded quartz boat in the mid zone of a reactor as herein described, - connecting the reactor to a vacuum line to pump down to less than 200 mm Hg incorporation of the gases into the mixing chamber and subsequently in reactor - de-oxygenation of the gases followed by removal of moisture - growth of nanomaterial and carbon nanotubes under different conditions as herein described. c. fabrication of hybrid nanocomposite comprising the steps of: -mixing of curing agent, also known as hardner in a resin, also known as polymer in a ratio of 100:0.2 to 100:5 at a temperature of 10 to 50°C -mixing of accelerator, also known as catalyst with solvent in a mixture of resin and hardner in ratio of 100:0.2 to 100:5 at a temperature of 10 to 50°C -dipping the nanomaterial and carbon nanotube coated fiber in the mixture of resin, hardner and catalyst and keeping in the mould to get a shape of mould known as preform, - loading of the perform in hydraulic press and curing at a pressure of 1 to 10 kg/cm2, and temperature of 25-100°C for a period of 1-24 hours. 3. A process for preparation of a nanomaterial and carbon nanotube as claimed in claim 2 wherein the carbon fiber is heated in an atmosphere of air, nitrogen, oxygen, Argon, Hydrogen, CO2 and mixtures thereof. 4. A nanomaterial and carbon nanotube and a process for preparation thereof as claimed in claim 1 and 2 wherein the carbon fibers are rayon based, polyacrylonitrile based and pitched based. 5. A carbon nanotube and nanomaterials, and a process for preparation thereof as claimed in claim 2 wherein the catalyst is selected from Group VIII metals consisting of Ni (Nickel), Ru (Ruthenum), Rh (Rhodium), Pd (Palladium), Ir (Iridium) and Pt (Platinum) and/or mixture thereof, Group VIb metals consisting of Cr (Chromium), Mo (Molybdenum) and W (Tungsten) and/or mixture thereof, and mixture of group VIII metals consisting of Ni (Nickel), Ru (Ruthenium), Rh (Rhodium), Pd (Palladium), Ir (Iridium) and Pt (Platinum) and Group VIb metals consisting of Cr (Chromium), Mo (Molybdenum) and W (Tungsten). 6. A carbon nanotube and nanomaterials, and a process for preparation thereof using mixed catalyst as claimed in claim 5 wherein the catalyst is comprising at least one group VIII metal and at least one group VIb metal in a ratio of one part of Cr or other metal from group VIb and at least 2 or more part of Ni or other metal from group VIII 7. A process for preparation of a carbon nanotube and nanomateria! as claimed in claim 2, wherein the oxidizing agents used in dip coating are metal, metal sulfide, metal disulifide, metal halide and metal sulphate in which metals are group VIII metals consisting of Ni, Ru, Rh, Pd, Ir, and group VIb metals consisting of Cr, Mo, W and mixture thereof reducing agents are group of metal consisting of Na, Mg, Al, Zn, Cu and mixtures thereof, metal hydrides consisting of Na, Mg, Al, Zn, Cu and mixtures thereof, metal hypophosphite consisting of Na, Mg, Al, Zn, Cu and mixtures thereof and chelating agents are consisting of water, carbohydrates, including polysaccharides, organic acids with more than one coordination group lipids, steroids, amino acids and relates compounds, peptides, phosphate, nucleotides, tetrapyrrois, ferrioxamines, ionophores, such as gramicidin, monensin, valinomycin, phenolics, 2, 2'-bipyridyldimercaptopropanol, ethylenedioxy-diethylenedinitrilo- tetraacetic acid, ethylene,glycol-bis(2-aminoethyl)-N,N.N',N"- tetraacetic acid, lonophores-nitrilotrriacetic acid, NTA ortho- Phenanthroline, salicylic acid, triethanolamine, sodium succinate, sodium acetate, ethylene diamine, ethylenediaminetetraacetic acid, dethylenetriaminepentaacetic acid, ethylenedinitrilotetraatic acid, and mixture thereof. 8. A process for preparation of a nanomaterial and carbon nanotube as claimed in claim 2, wherein the buffer solution used in dip coating is group of week acid and its salt and mixture thereof in which week acids consisting of succinic acid formic acid acetic acid, tricholoroacetic acid, hydrofluoric acid, hydrocynic acid, hydrogen sulphide, water and group of sodium and/or potassium consisting of succinic acid, formic acid, acetic, trichoroacetic acid, hydrofluoric acid, hydrocynic acid and hydrogen sulphide. 9. A process for preparation of nanomaterial and carbon nanotube as claimed in claim 2, wherein the coating of the catalyst is done in an environment of nitrogen, argon, helium and mixture thereof and at a temperature of 10-125°C for a time period of 10-3600 second to obtain a thickness of 50-200 nm. 10. A process for the preparation of nanomaterial and carbon nanotube as claimed in claim 2, the gases comprise carbon containing gas such as group of saturated hydrocarbons, aliphatic hydrocarbons, oxygenated hydrocarbons, aromatic hydrocarbons, alcohols, carbon monoxide and mixture thereof, reducing gas such as group of gases consisting of hydrogen, chlorine and mixtures thereof and diluent gas such as group consisting of nitrogen, argon, helium and mixture thereof and the ratio of these gases are 0:100 to 50: 50, 0:5:95 to 60:20:20 and 0:100 to 60:40 between reducing:diluent gases, carbon containing gas:reducing gas:diluent gas, and carbon containing gas:diluent gas respectively. 11. A process for preparation of a nanomaterial and carbon nanotube as claimed in claim 2 wherein the nanomaterial is formed at a temperature range of 400 to 900°C in a time period of 10 to 7200 sec, which has a diameter of 1 to 80 nm, wherein at least 20% has a diameter less than 30 nm, and the carbon nanotube is formed at a temperature range of 650- 1500°C in a time period of 10 to 3600 sec, which has a diameter of 1 to 60 nm and length of 9000 to 20000 nm, wherein at least 70% of the carbon nanotubes have diameter less than 40 rim and 40% carbon nanotubes are single wall. 12. A nanomaterial and carbon nonotube coated carbon fiber reinforcedpolymer hybrid nanocomposite and a process for preparation thereof as claimed in claim 1 and 2 wherein the polymer is thermosetting resin consisting of polymide, polyester, polyrre thane, polysulfonamide, polycarbonate, polyurea, polyphosphonoamide, polyarylate, polyimide, poly (amic ester), poly (ester amide), poly(enaryloxynitrile) matrix and/or mixtures thereof. 13. A nanomaterial and carbon nonotube coated carbon fiber reinforcedpolymer hybrid nanocomposite and a process for preparation thereof as claimed in claim 12 wherein the polyester is a copolymer of acid consisting polyester of terephthalic acid, isophthalic acid, pruhalic acid. trimellitic acid, pyromellitic acid, hexahydrophthalic acid, adipic acid or sebacic acid and diol consisting of 1,2-ethanediol, 1,2-propanediol, trimethylolpropane, neopentyl glycol, 1,3-butanediol, 1,4,-butanediol, pentaerythritol, glycerol, tris(hydroxyethyl) isocyanurate or ethoxylated bisphenol A. 14. A nanomaterial and carbon nonotube coated carbon fiber reinforced-polymer hybrid nanocomposite and a process for preparation thereof as claimed in claim 13, wherein the polyester has an acid number in the range 1 to 150 mg KOH per gram, hydroxyl number less than 30 mg KOH per gram, number average molecular weight (Mn) is less than 2000 and viscosity in the range of 12000-15000 cP. 15. A process for preparation of nanomaterial and carbon nonotube coated carbon fiber reinforced-polymer hybrid nanocomposite as claimed in claim 2, wherein the curing agent is temperature activatable selected from group consisting of benzoyl peroxide, dicumyl peroxide, hydrogen peroxide, methyl peroxide, ethyl peroxide, methyl ethyl ketone peroxide, sulphur and mixture thereof and the mixing of curing agent, in polymer is done at 20-100°C. 16. The nanomaterial and carbon nonotube coated carbon fiber reinforced-polymer hybrid nanocomposite according to Claim 2, wherein the organometallic compound acts as an accelerator suitable for peroxide curing of an unsaturated polyester resin is present in an amount between 2 and 10 per cent by weight based on weight of resin, wherein the organometallic compound consists essentially of one or more cobaltcontaining salts selected from the group consisting of cobalt octoate, cobalt 2-ethylhexanoate, and cobalt naphtenate, one or more solvents, and, optionally, one or more stabilizers, wherein the solvents are selected from the group consisting of pentane, isopentane, hexane, diethyleneglycol,dipropyleneglycol, ethyleneglycol, isobutanol, peiitanol, triethylphosphate, triethylphosphite, dibutylmaleate, dibutylsuccinate, and ethylacetate. 17. The naiiomaterial and carbon nonotube coated carbon fiber reinforced-polymer hybrid nanocomposite according to Claim 16 wherein the solution comprising 20 to 99% w/w of solvent (s), and 1 to 80% w/w of cobalt-containing salt (s), and optionally 0.1-8%w/w of stabilizer (s), up to a total of 1 00% w/w. 18. A method of manufacturing nanomaterial and carbon nanotube coated carbon liber reinforced-polymer hybrid nanocomposite as claimed in Claim 2, wherein nanoparticle and carbon nanotube coated support materials are added at 2-60% by volume to said mixture of polymer matrix, curing agent and accelerator prior to said polymer being cured. 19. A process for preparation of nanomaterial and carbon nanotube coated carbon fiber reinforced-polymer hybrid nanocomposite as claimed in claim 2, wherein the curing step is carried out below the degradation temperature of polymer i.e., at a temperature of 25-100°C, under a pressure of about 1 to 10 kg/cm2 and for a period of 1-24 hours. 20 A process as claimed in claim 2 wherein coating of the catalyst is done at a temperature of 10 to 125°C for a period of 10 to 3600 seconds by dipping the carbon fiber in acidic bath provided in a dip-coating setup wherein the bath is prepared by dissolving oxidizing agent in deionized water, in a ratio of 1:100 to 9:100 which is added with reducing agent, chelating agent and buffer in a ratio of 1:1 to 1:5, 1:1 to 1:10 and 1:0.10 to 1:1 followed by stirring of the mixture to obtain the acidic bath. 22. A process as claimed in claim 2 wherein the coating of the catalyst is done by spraying a brown coloured solution on carbon fiber wherein the preparation of the solution comprises the steps of: -dissolving metal nitrate in de-ionized water in a ratio of 1:5 to 1:15 which is added with equal amount of carbonate to obtain a brown coloured solution stirring of the solution so obtained to get a semi solid mass followed by heating the same in an oven at a temperature of 75 to 200°C for a period of 1000 to 86400 seconds heating the resulting mass thus obtained in a furnace at a temperature of 300 to 700°C for a period of 1000 to 7000 seconds followed by cooling down the same to room temperature to obtain a brown coloured mass addition of methyl alcohol with the powder followed by stirring to obtain the solution. 23. A nanomaterial and carbon nanotube coated carbon fiber reinforcedpolymer hybrid nanocomposite as claimed in claim 1 wherein the nanocomposite comprises carbon fiber varied from 1 to 60 wt% polymer varied from 99 to 40% carbon nanotube varies from 1 to 70 wt% with respect to carbon fiber (excluding all other composition) accelerator (catalyst) in composites varies from 100:0.2 to 100:5 (resin:catalyst) curatives (hardner) varies from 100:0.2 to 100:5 (resin:hardner) and nanoparticles varies from 1 to 15% based on carbon nanotube. 24. A nanomaterial and carbon nanotube coated carbon fiber reinforcedpolyrner hybrid nanocomposite and a process for preparation of a carbon nanotube coated carbon fiber reinforced-polymer hybrid nanocomposite substantially as herein described with reference to accompanying drawings.

Full Text

FIELD OF THE INVENTION
The present invention relates to carbon nanotube and nanoparticle
coated carbon fiber reinforced-polymer hybrid nanocomposite \vith
improved thermomechanical properties and a process for preparation
thereof.
PRIOR ART
Various types of composite materials, i.e., polymer matrix including
thermoplastic and thermosetting, ceramic matrix, carbon matrix, metal
matrix, etc are available for the last 50 years. These composite materials
have many advantages over the conventional materials like high strength
to weight ratio properties, exceptional temperature and corrosion
resistance, high fatigue strength, excellent impact resistance, excellent
solvent and wear resistance, very low internal friction coefficient, ability
to engineer for use of structural, mechanical and thermal response, very
good thermoformability, large-volume production capabilities, no harmful
emission during production, etc. These are widely used through out our
daily life including construction industries. But very few items are used
in aerospace, automobile and medical industries due to the specified
mechanical properties, which are not sufficient in these high tech
applications. At the same time the inexpensive production techniques
suitable for down to earth industries are not available.
Conventional carbon nanotube polymer composites are prepared by two
ways. One root is the addition of carbon nanotube in the polymer matrix
using costly mixer, if the matrix is available in the solid form. Otherwise
it is done by sonication if the matrix material is available in liquid form.
In both cases the uniform dispersion of carbon nanotube is a major
problem. Researchers did not find any substantial improvement in
mechanical properties, thermal stability, electrical resistivity, magnetic
properties using this technique. Other root is the mixing of carbon
nanotube in the precursor of fibers, i.e., pitch in the case of pitch based
carbon fiber then extruding the fiber through a spinneret. Researchers
have made composites using this fiber and polymer matrix. Again they
did not find any substantial improvement in all these properties, i.e.,
mechanical, thermal stability, electrical resistivity, magnetic, etc due to
the uneven distribution of carbon nanotube. Keeping this in mind a
process in this invention has been developed where the carbon fiber is
coated with carbon nanotubes through out the surface and then hybrid
nanocomposites are prepared using this carbon nanotube coated carbon
fiber. In this the question of distribution of carbon nanotube does not
arise. In this case we find an excellent improvement is found in
mechanical properties, electrical resistivity and thermal stability, etc.
BACKGROUND OF THE INVENTION
Pitch-based carbon fibers, having a highly ordered morphology, are well
known in the art. That is, when heated, pitch materials form an isotropic
mass. As heating continues, spherical bodies begin to form. The
spherical bodies are of an anisotropic liquid crystalline nature as viewed
under polarized light. These spheres continue to grow and coalesce until
a dense continuous anisotropic phase forms, which phase has been
termed the "mesophase." Thus, the mesophase is the intermediate phase
or liquid crystalline region between the isotropic pitch and the semi-coke
obtainable at higher temperatures. Mesophase pitch is extruded into
fibers, oxidatively stabilized, and carbonized at high temperatures to
form mesophase pitch-based carbon fibers.
As compared to PAN-based carbon fibers, these mesophase pitch-based
carbon fibers have a relatively high tensile modulus but a relatively low
tensile strength and a relatively low compressive strength. That is, the
highly graphitic structure of these polymers is responsible for their high
modulus and high thermal conductivity, but also for their low strength.
The structured, crystalline morphology that provides for the high tensile
modulus also allows for the brittle failure of the fibers caused by the
propagation of even minute flaws.
In order to reduce the tendency of carbon fibers to fail through flaw
propagation as described above, a variety of prior art patents have
provided methods for producing such fibers with a less ordered, more
random microstructure. To date, these efforts have focused on the
method by which the fiber is extruded, including modification of the
geometry of the die through which the fiber is extruded, rather than on
composition modification.
Carbon nanotubes, multilayer tubules by evaporating carbon in an arc
discharge were first reported in 1991 by lijima (1). These linear fullerenes
are attracting increasing interest as constituents of novel nanoscale
materials and device structures. Defect-free nanotubes are expected to
have remarkable mechanical, electronic and magnetic properties that will
be tunable by varying the diameter, number of concentric shells, and
chirality of the tube.
Later on in 1993, lijima and Ichihashi (2) and Bethune et al. (3, 4)
independently discovered a single-wall nanotube by vaporizing carbon
together with a transition metal such as iron or cobalt in an arc
generator. These syntheses produced low yields of non-uniform
nanotubes mixed with large amounts of soot and metal particles.
Subsequently Richard Quo et al. (5) disclose a process for making singlewall
nanotubes having diameters of about 1 nm and lengths of several
microns. The nanotubes aggregated into "ropes" in which many tubes
were held together by van der Waals forces. The nanotubes produced
were remarkably uniform in diameter.
Significant improvement in yield of 70 to 90% and the 10, 10
configuration (a chain of 10 hexagons around the circumference of the
nanotube) was reported by Rao et. al (6) . The product consisted of fibers
approximately 10 to 20 nm in diameter and many micrometers long
comprising randomly oriented single-wall nanotubes, each nanotube
having a diameter of about 1.38 nm.
Liu et al. (7) reported single-wall fullerene nanotubes that are converted
from nearly endless, highly tangled ropes into short, open-ended pipes
that behave as individual macromolecules. Also described therein is the
termination of the open ends of the nanotubes with carboxylic acid
groups after treatment in acid. This is followed by reaction with SOCb at
room temperature to form the corresponding acid chloride.
This single wall carbon nanotube has an outstanding strength of
~37GPa, stiffness of -640 GPa, Young's modulus of ~ 2.8 to 3.6 TPa,
specific gravity of ~ 1.30, electrical conductivity of ~ 106 S/m, thermal
conductivity of ~ 2000 W/mK, specific surface area of 1350 m2/g, etc.
Researchers are trying to utilize these outstanding properties through
several roots.
One group of researchers dispersed carbon nanotube into a wide range of
polymeric materials to produce composites with unique properties
ranging from high performance engineering materials to additives for
accelerating chemical reactions. The dispersion is achieved by either
shear mixing using a Haake Polylab unit or Brabender Labstation or by
the use of a high energy ultrasonic probe when dispersion into a liquid is
required. The polymeric materials are polyamine (8), polyether (8)
bisphenol A (9), epoxy (10), poly(m-phenylene vinylene-co-2,5-dioctoxy-pphenylene
vinylene (11), polymethylmethacrylate (12, 13), polyimide
(14,15), poly(vinylidene fluoride) (16) and poly(vinylpyrrolidone) (16),
acrylic polymers (17), fluoropolymers (17), polycarbonates (17),
polycyanurates (17), polyesters (17), polysiloxanes (17), polyurethanes
(17), polythiophenes (18), polyvinylcarbazole (19), polyimides (20),
polysulfonamides (20), polythiophenylenes (20), polyureas (20),
polyurethanes (20), elastomers (21), silicones (21), fluorinated polymers
(21), polysulfones (22, 23), polyoxyalkylenes (24), etc.
Another group of researchers (25-27) mixed carbon nanotube before
polymerization of monomer to improve the dispersion of carbon nanotube
into polymer matrix.
Another group of researchers (28-36) mixed carbon nanotube into the
precursor of fiber or polymer and then extrude into fiber for further
improvement in dispersion of carbon nanotube into matrix material and
to get the best mechanical properties.
Another group of researchers wrote few review papers based on the
carbon nanotube polymer composites (37-45).
Because of their outstanding properties, further progress towards better
distribution of carbon nanotube in matrix material is desirable.
Keeping this in mind, the present invention is to synthesis carbon
nanotube on the surface of carbon fiber to eliminate the problem of
uneven distribution of carbon nanotube in the matrix material. This
carbon nanotube coated carbon fiber will be used to make a polymer
composite material for high tech application.
OBJECTS OF THE INVENTION
The object of this invention is to provide a carbon nanotube and
nanoparticle coated carbon fiber reinforced-polymer hybrid
nanocomposite and a process thereof.
Another object of the invention is to provide a carbon nanotube and
nanoparticle coated carbon fiber reinforced-polymer hybrid
nanocomposite and a process thereof for coating on the long carbon fiber
having micronsized diameter.
Another object of the invention is to provide a carbon nanotube and
nanoparticle coated carbon fiber reinforced-polymer hybrid
nanocomposite and a process thereof for uniform growth of carbon
nanotube on the surface of long carbon fiber
Still another object is to provide a carbon nanotube and nanoparticle
coated carbon fiber reinforced-polymer hybrid nanocomposite and a
process thereof for manufacturing of fiber reinforced polymer hybrid
nanocomposites using carbon nanotube coated fiber and polyester resin.
The next objective is to provide a carbon nanotube coated carbon fiber
reinforced-polymer hybrid nanocomposite and a process thereof to
characterize the newly developed fiber reinforced polymer
nanocomposites through surface area, scanning electron microscopy,
transmission electron microscopy, X-ray diffraction studies, storage
modulus, loss modulus, loss tangent and thermal stability in various
atmosphere, I-V characteristics, magnetic properties, etc.
BRIEF DESCRITPION OF THE ACOMPNAYING DRAWING AND
TABLES
Further, objects and advantages of this invention will be more apparent
from the ensuing description when read in conjunction with the
accompanying drawings and wherein:
Figure 1 shows a schematic diagram of coating unit
Figure 2 shows a Schematic diagram of reactor
Figure 3: XRD pattern of as-received carbon fiber, nanoparticles coated
carbon fiber, and nanoparticles and carbon iianotubes coated carbon
fiber.
Figure 4 is a SEM micrograph of as-received carbon fiber at a
magnification of 8000X
Figure 5 shows EDAX data of as-received carbon fiber at a magnification
of 8000X
Figure 6 is a SEM micrograph of nanoparticle and carbon nanotube
coated carbon fiber at a
magnification of 3000X
Figure 7 is a SEM micrograph of nanoparticle and carbon nanotube
coated carbon fiber at a
magnification of 80000X
Figure 8 is a TEM micrograph of as-received carbon fiber
Figure 9 is a TEM micrograph of nanoparticles and carbon nanotube
coated carbon fiber
Figure 10 is a TEM micrograph of nanoparticles and carbon nanotube
grown on carbon fiber

Figure 11 is a SAD pattern of nanoparticles and carbon nanotube grown
on carbon fiber
Figure 12 is a TEM micrograph of nanoparticles and carbon nanotube
grown on carbon fiber
Figure 13: TGA curves (D: as received carbon fiber; and O: nanoparticles
and carbon nanotubes coated carbon fiber) in nitrogen atmosphere at a
heating rate of 10°C/minute
Figure 14: Derivative (% weight/minutes.) curves for (Li: as received
carbon fiber; and O: nanoparticles and carbon nanotubes coated carbon
fiber) in nitrogen atmosphere at a heating rate of 10°C/minute
Figure 15: Heat flow curves (D: as received carbon fiber; and A:
nanoparticles and carbon nanotubes coated carbon fiber) in nitrogen
atmosphere at a heating rate of 10°C/minute
Figure 16: TGA curves (D: as-received, carbon fiber; and A:
nanoparticles and carbon nanotubes coated carbon fiber) in oxygen
atmosphere at a heating rate of 10°C/ minute
Figure 17: Derivative (% weight/ minutes.) curves (D: as-received carbon
fiber; and A: nanoparticles and carbon nanotubes coated carbon fiber) in
oxygen atmosphere at a heating rate of IOC/minute
Figure 18: Heat flow curves (D: as-received carbon fiber; and A:
nanoparticles and carbon nanotubes coated carbon fiber) in oxygen
atmosphere at a heating rate of 10°C/ minute
Figure 19: Heat flow vs. time curves (D: as-received carbon fiber; and A:
nanoparticles and carbon nanotubes coated carbon fiber) in oxygen
atmosphere at a heating rate of 10°C/ minute
Figure 2O: Storage modulus vs. temperature curves for (LJ: as-received
carbon fiber; and A: nanoparticles and carbon nanotubes coated carbon
fiber) hybrid nanocomposites
Figure 21: Relative storage modulus vs. temperature curves for (LJ: asreceived
carbon liber; and A: nanoparticles and carbon nanotubes
coated carbon fiber, coating time 30 minutes) hybrid nanocomposites
Figure 22: Loss modulus vs. temperature for (D: as-received carbon
fiber; and A: nanoparticles and carbon nanotubes coated carbon fiber)
hybrid nanocomposites
Figure 23: Relative loss modulus vs. temperature curves for (D: asreceived
carbon fiber; and A: nanoparticles and carbon nanotubes
coated carbon fiber) hybrid nanocomposites
Figure 24: Tan 8 vs. temperature curves for (D: as-received carbon fiber;
and A: nanoparticles and carbon nanotubes coated carbon fiber) hybrid
Table 3 shows degradation temperature corresponding to peak for asreceived
carbon fiber and nanomaterial and carbon nanotube coated
carbon fiber in oxygen atmosphere
According to this invention there is provided a nanomaterial and carbon
nanotube coated carbon fiber reinforced-polymer hybrid nanocomposite
comprising supported material, which is coated with a carbon product
comprising carbon nanotubes and nanomaterials, and a polymer matrix
material.
Further according to this invention there is provided a process for
preparation of a nanomaterial and carbon nanotube coated carbon fiber
reinforced-polymer hybrid nanocomposite comprising the steps of :
a. heating the carbon fiber at a temperature of 100-600°C for a time
period of 60-1800 second, coating of catalyst on the surface of carbon
fiber followed by heating the catalyst coated carbon fiber in an oven at a
temperature of 50-200°C for a period of 100 to 10,000 seconds.
b. keeping of catalyst coated fabric or fiber loaded quartz boat in
the mid zone of a reactor as herein described,
- connecting the reactor to a vacuum line to pump down to less
than 200 mm Hg
incorporation of the gases into the mixing chamber and
subsequently in reactor
- de-oxygenation of the gases followed by removal of moisture
- growth of nanomaterial and carbon nanotubes under different
conditions as herein described.
c. fabrication of hybrid nanocomposite comprising the steps of:
-mixing of curing agent, also known as hardner in a resin, also
known as polymer in a ratio of 100:0.2 to 100:5 at a temperature of 10 to
50°C
-mixing of accelerator, also known as catalyst with solvent in a
mixture of resin and hardner in ratio of 100:0.2 to 100:5 at a
temperature of 10 to 50°C
-dipping the nanomaterial and carbon nanotube coated fiber in
the mixture of resin, hardner and catalyst and keeping in the mould to
get a shape of mould known as preform,
- loading of the perform in hydraulic press and curing at a
pressure of 1 to 10 kg/cm2, and temperature of 25-100°C for a period of
The additional features of the invention have been depicted in the
dependent claims.
DETAILED DESCRITPION OF THE INVENTION
According to the present invention a technique has been developed to
fabricate fiber reinforced polymer hybrid nanocomposites from carbon
nanotube and nanomaterials coated carbon fiber and polyester resin.
Further according to this invention:
1. Fiber reinforced polymer hybrid nanocomposite is prepared using
nanomaterial coated carbon fiber and polyester resin
2. Various nanomaterials acts as catalyst i.e., cobalt (Co), nickel
(Ni), ruthenium (Ru), rhodium
(Rh), palladium (Pd), iridium (Ir), platinum (Pt) chromium (Cr), tungsten
(W) are tested to grow carbon nanotube on the surface of carbon fiber.
3. Various mixed nanomaterials acts as catalyst i.e., combination of
any two following metals, i.e., cobalt (Co), nickel (Ni), ruthenium (Ru),
rhodium (Rh), palladium (Pd), iridium (Ir), platinum (Pt) chromium (Cr),
tungsten (W) are tested to grow carbon nanotube on the surface of
carbon fiber.
4. A high purity low coat process has been developed to coat carbon
nanotube on the surface of carbon fiber.
5. Various environments, i.e., nitrogen, hydrogen, acetylene,
methane, etc are tested to get a good and uniform coating of
nanomaterials and carbon nanotube on the surface of long carbon fiber.
6. Various mixed environments using nitrogen, hydrogen, acetylene,
methane, etc are tested to get a good and uniform coating of
nanomaterials and carbon nanotube on the surface of long carbon fiber.
7. Various compositions of mixed environments using nitrogen,
hydrogen, acetylene, methane, etc are tested to get a good and uniform
coating of nanomaterials and carbon nanotube on the surface of long
carbon fiber.
8. Different temperatures to crack me thane/acetylene are tested to
get a good and uniform coating of nanomaterials and carbon nanotube
on the surface of long carbon fiber.
9. Different times to crack methane/acetylene are tested to get a
good and uniform coating of nanomaterials and carbon nanotube on the
surface of long carbon fiber.
10. A process has been developed to prepare nanomaterials and
carbon nanotube coated carbon fiber nanocomposite.
The invention also provides compositions used to coat catalyst and
carbon nanotube on the surface of carbon fiber.
Surface area, scanning electron microscopy, transmission electron
microscopy, X-ray diffraction studies, storage modulus, loss modulus,
loss tangent and thermal stability in various atmosphere, etc. have been
conducted on appropriately designed specimens to characterize the
materials.
The hybrid nanocomposite is prepared in three steps, which are
described below with the help of different embodiments, which are to be
taken as example without restricting the scope of the invention to the
same.
(1) Coating of Catalyst on the Surface of Carbon Fiber/Fabric
The preparation and deposition of catalyst on the substrate are critical
steps. A uniform and optimum thickness of catalyst is essential to get a
niform and good coating of carbon nanotubes through out the surface
of carbon fiber/fabric.
Embodiment-1
Catalyst is coated on the surface of carbon fiber by dip coating technique
using an acidic bath shown in Figure 1. The compositions of bath are
given in Table 1. The bath is prepared by first dissolving the required
amount of oxidizing agent in de-ionized water and subsequently other
chemicals are added in the solution. The mixture is continuously stirred
for -30 minutes to ensure the proper mixing of all chemicals. Finally this
green colored solution is used in the dip-coating set-up, Figure 1 to
deposit catalyst on the surface of carbon fiber/fabric. The coating is
produced by the controlled chemical reduction of metallic ions onto a
catalytic surface. For the further detail reference may be made to
claim 20 and 21.
After dipping the carbon fiber in the bath it is placed in an oven at a
temperature of 100°C for -20 min.
The temperature of electroless nickel solutions is one of the important
factors affecting the rate of deposition. The rate of deposition is low at
temperatures below 65°C, and increases with an increase in
temperature. This is true for almost all the systems. The operating
temperature for this study is about 65-75°C. All the elements of group
VIb and VIII are applicable to this invention.
Embodiment-2
Metal catalyst is prepared by mixing of metal nitrate (for example iron
nitrate) and metal carbonate (for example iron carbonate). 50 g of metal
nitrate is dissolved in 500 ml of de-ionized water. When metal nitrate is
fully dissolved in water, an equal amount of metal carbonate was added
in the solution. The resulting brown colored solution is stirred
continuously till it turned into a semi solid mass. This semisolid mass is
kept in an oven at a temperature of 120°C for -12 hrs to vaporize all
water. Then the resulting mass is kept in furnace at 500°C for 8 hrs.
After cooling down to room temperature the brown colored mass was
ground in an agate mortar. The resulting brown colored powder is used
as catalyst to grow carbon nanotubes. The coating of this catalyst on the
surface of carbon fiber/fabric is done by spraying the solution of brown
colored powder. The solution was prepared by mixing the -10 g of
powder in 500 ml of methyl alcohol. It is stirred at room temperature for
-30 min. After spraying this solution on carbon fiber the fiber is placed
in an oven at a temperature of 100°C for -30 min. For the further
details reference may be made to claim 22.
(2) Coating of Nanomaterials and Carbon Nanotubes (CNTs) on the
Surface of Carbon Fiber Fabric
The coating of carbon nanotubes was conducted in a tubular reactor
placed horizontally, and the schematic diagram of the experimental setup
was shown in Figure 2. This reactor had a quartz tube of 84 cm length
with outer diameter of 49 mm and inside diameter of 45 mm. It was
constructed in such a way that the carbon fiber/fabric loaded quartz
boat could be easily inserted and removed from the reactor. The reactor
was heated in a three zone tubular furnace. A proportional temperature
controller controls the furnace temperature in each zone. The
temperature was kept around 700 to 900°C in the mid zone of furnace to
facilitate the decomposition of precursor gases just above the quartz
boat. The inlet and outlet temperatures were maintained at 300-600°C.
Nitrogen, hydrogen, methane, ethane, propane, carbon dioxide, ethylene
and acetylene were used as precursor gases. Each gas has its own
function. Acetylene / methane / ethylene / propane / carbondioxide / ethane
acts as a source of carbon, hydrogen acts as a reducing gas to reduce the
catalytic layer and nitrogen acts as a carrier gas and also provides the
inert atmosphere inside the reactor. The catalyst coated carbon
fiber/fabric was kept in the middle zone of the reactor. The reactor was
connected to a vacuum line and then pumped down to less than 200 mm
Hg. The gases entered in the reactor through three different non-return
valves. The flow rates of gases were measured by rotometers, as shown in
Figure 2. Gases are first deoxygenated by passing them through an
alkaline pyrogallol solution and subsequently moisture is removed by
passing them through a silica gel bed. The gases were mixed before
entering into the reactor. The water circulation arrangement was made at
inlet and exit of the reactors tube to keep the temperature at desired
level. Water is also used as a coolant in the condenser. Any condensable
in the reactor effluent was collected in a liquid collector where as
noncondensables were sent to the exit flow, which was recorded by the
pressure indicator dial and then vented to the atmosphere. The different
conditions used in each run to grow carbon nanotubes.
Embodiment- I
140 X 30 mm/mm catalyst coated fabric or catalyst coated carbon fiber
having 3 to 300 micrometer in diameter is kept in a quartz boat. The
fabric or fiber loaded quartz boat is inserted in a reactor shown in Figure
2. As the reactor is connected to a vacuum line the gas of reactor was
pumped down to less than 200 mm Hg to remove oxygen from the
reactor, i.e., to make an inert atmosphere. After that nitrogen was
inserted in the reactor. When it comes to the atmospheric pressure again
it was pumped down to less than 200 mm Hg. This process is continued

10 times till free of oxygen. In the next step the temperature of reactor
was increased up to 600°C in an environment of nitrogen. The rate of
nitrogen flow was kept constant at 120 ml/min. At this temperature the
temperature of reactor is kept constant for 30 minutes to break the
coating of catalyst to nanoparticles in nitrogen atmosphere. After 30
minutes of holding time the reactor temperature is raised to 770°C in the
same nitrogen atmosphere. When the temperature becomes constant at
770°C, acetylene was allowed to flow at the rate of 25 ml/min along with
the flow of nitrogen gas. The reaction was carried out at this temperature
for 20 minutes. After 20 minutes of holding time the reactor was allowed
to cool to room temperature and samples were taken out from the
furnace for characterization of carbon nanotube and fabrication of
nanocomposites.
Embodiment- 2
All conditions used in embodiment -1 of coating of nariomaterials and
carbon nanotubes (CNTs) on the surface of carbon fiber/fabric are same
except the growth time and the flow rate of acetylene. Flow rate of
acetylene is kept at 25 ml/min. and the growth time is increased up to
In this run the growth time is further increased to 30 min. All other
conditions are same as embodiment -1 of coating of na.nomaterials and
carbon nanotubes (CNTs) on the surface of carbon fiber/fabric.
Embodiment -4
In this condition to grow the carbon nanotubes on the surface of carbon
fiber/fabric, the hydrogen gas is used as reducing gas to reduce the
catalytic layer. Here, first the temperature of reactor is increased up to
600°C in nitrogen atmosphere with a flow rate of 120 ml/min. Then the
flow of H2 is started and kept constant at 15 ml/min. for 30 minutes to
reduce the catalytic layer. After this the reactor is heated up to 800°C
and the flow of acetylene is started and held constant at 25 ml/min. for
25 minutes. At the end of reaction the reactor is allowed to cool to room
temperature. After cooling the samples were removed from the furnace
for characterization.
(3) Fabrication of Polymer Hybrid Nanocomposites:
Embodiment -1
The carbon fabric is cut in right shape using the template from
nanomaterial and carbon nanotube coated carbon fiber. The matrix used
to prepare the hybrid nanocomposites is polyester resin. The weight ratio
of polyester resin:catalyst:hardner is 100:2:2. Total number of layers
used to prepare the hybrid nanocomposites was 3. The composite was
prepared by conventional hand lay up technique. The preform was
loaded in hydraulic press. The pressure cycle was 3.5 kg/cm2. The
preform was allowed to cure at a temperature of 50°C for 16 hours. The
volume fraction of fiber was -45%. After curing the hybrid
nanocomposites were removed from hydraulic press and was used for the
characterization of volume fraction of fibers, storage modulus, loss
modulus, glass transition temperature, etc. Reference may be made to
claim 2 for the fabrication of nanocomposite.
Embodiment 2
The carbon fabric is cut in right shape using the template from asreceived
carbon fabric, i.e., uncoated carbon fabric. All other conditions
are same as mentioned in embodiment 1 of fabrication of polymer hybrid
nanocomposite.
The potentially outstanding mechanical properties of carbon nanotubes
(Young's modulus -1.25 TPa, Tensile strength -lOOGPa) will be of little
value unless they can be incorporated in a matrix to make a composite
material. Composite materials containing carbon fibers are, of course,
lready widely used in application ranging from aerospace to sports
equipments. In such materials the matrix can be plastic, epoxy, metal or
carbon. The incorporation of carbon fiber into matrix not only confers
strength and elasticity to the material but also greatly enhances
toughness that is its ability to resist cracking. In this context the carbon
nanotubes are an ideal candidate for further improvement of all these
above properties in high performance composite structures. But the
ability to disperse nanotubes into polymer is a major problem for
controlling the properties. Nanotubes that are in clumps or agglomerated
with other carbonaceous materials create defect and initiate failure. In
addition, they limit the efficiency with which nanotubes carry load. This
limitation has been illustrated explicitly in both polymer and ceramic
matrix composites. In this scenario an attempt is made to grow the
carbon nanotube on the surface of carbon fiber that will help to make a
very strong composite material in the world. Keeping this in mind the
carbon fiber was coated with various catalysts over a period of time,
temperature and composition of bath using dip coating shown in Figure
1. Now the catalyst coated carbon fiber was used to grow the
nanomaterials and carbon nanotubes on its surface using a special type
of reactor shown in Figure 2. During the growth of nanomaterials and
carbon nanotube, the temperature, time and volumetric flow rate of
carbon, containing gas, inert gas and reducing gas were varied. The
carbon fiber, and nanomaterial and carbon nanotube coated carbon fiber
were characterized through thermogravimetric analysis over a range of
temperature, environment (i.e.oxygen and nitrogen) and heating rate;
dynamic mechanical analysis; scanning electron microscopy;
transmission electron microscopy and x-ray diffraction studies to find
out optimum condition for formation of nanomaterial carbon nanotubes
on the surface of carbon fiber.
The compositions of coating solution are the major parameter affecting in
the coating process of catalyst; however, in addition to this, other
parameters like pH, temperature, bath loading factor, and the surface
area of the substrate also affect the thickness of coating on the
substrate. Four different types of compositions are studied in this work.
The compositions of coating solution are summarized in Table 1. The
catalyst-coated carbon fibers were characterized using XRD, SEM, TGA
and DTA analysis. It was found that the coating was possible for the
compositions 3 and 4 while in others (1 and 2) the coating was not
possible.
The nanomaterials and carbon nanotubes were coated on the
surface of carbon fiber using hot furnace. After the coating of
nanomaterials and carbon nanotubes on the surface of carbon fibers,
XRD analysis was performed on the nanomaterials and carbon
nanotubes coated carbon fibers to see the change in XRD pattern of
carbon fibers. Figure 3 shows the XRD pattern of carbon fiber before and
after the coating of nanomaterials and carbon nanotubes. The XRD
pattern of nanomaterials coated carbon fiber is also included, here. The
peak, around 20 = 26° is the characteristic peak of carbon fiber due to its
graphitic structure. The location and broadness of this peak indicate that
carbon fibers have a coke like character. The peak around 20-34° shows
nanomaterials (Here it is nickel. Because nickel sulphate and sodium
hypophosphite were used as an oxidizing and reducing agent to coat
nickel on carbon fiber respectively). Figure 3 also shows that the carbon
basal planes of the carbon structure are not changed by naiioscaled
coating because not change in the nature of peak corresponding to 20=
26°. The increase in noise is also observed after the growth of carbon
nanotubes. But this noise may be because of the high temperature
exposure of carbon fiber during the coating of nanomaterials and carbon
nanotubes.
Surface morphology of as-received carbon fiber, nanomaterials and
carbon nano tube-coated carbon fiber has been analyzed through
scanning electron microscope (SEM). The micrograph of as-received
carbon fiber is shown in Figure 4. The fiber surface is very smooth and
there is no pit mark on the surface of carbon fiber. The diameter- of
carbon fibers is calculated from this micrograph. It is seen that the
diameter of fibers at a magnification of 8000X is varied from 4 to 6 urn.
Figure 5 shows EDAX analysis of as received carbon fiber.
SEM micrographs of carbon fiber coated with nariomaterials and
carbon nanotubes have been shown in Figure 6 at a magnification of
3000. The micrograph shows a good and uniform coating of carbon fiber
surface by nanomaterials and carbon nanotubes. To calculate the length
and diameter of carbon nanotubes, a single strand of carbon nanotube is
carefully chosen from Figure 4 and shown in Figure 7 at a magnification
80000X. The length and diameter of the carbon nanotubes, measured
from these micrographs is -15,000 nm and -40 nm respectively. Figure
7 also shows that the carbon nanotube has a helical structure. This
helical morphology comes from the anisotropic properties of catalyst
particles. These observations are further supported by TEM analysis,
which will be discussed in the next section.
TEM study gives detailed information about the nanostructure of
carbon nanotubes. Figure 8 shows a typical micrograph of as-received
carbon fiber. This micrograph has been taken at a voltage of 120 kVA.
The diameter calculated from this micrograph confirms the result
obtained through SEM measurements. Figure 9 shows a TEM
micrograph of carbon nanotube coated carbon fiber. It shows a rough
surface as compared to the as-received carbon, fiber micrograph shown in
Figure 8 because of the presence of carbon nanotubes on. the surface of
carbon fiber. Another micrograph of carbon nanotube coated on the
surface of carbon fiber is shown in Figure 10. It shows the bundles of
carbon nanotubes. The kinks in the structure of carbon nanotube are
also clearly visible in the micrograph. These kinks are may be due to the
coiled structure, helical structure or presence of pentagon/ heptagon
bonds in the structure of carbon nanotubes. The corresponding selective
area diffraction (SAD) pattern is also shown in Figure 11. It shows the
crystalline nature of carbon nanotubes. The ring patterns show that the
carbon fibers are not only crystalline but. are also somewhat graphitic.
The brightest ring corresponds to the (002) reflection of hexagonal
graphite. The next continuous ring seen in the diffraction pattern
corresponds to the (110) reflection of hexagonal graphite. There is no
difference in the intensity for this particular diffracted ring, which
suggests that there is no preferred orientation along the a*- or b*-axes. I t
is observed from the micrographs that the nanotubes present near the
carbon fiber surface contains more nanoparticles than the ones situated
far from the surface i.e. there are more nanoparticles observed at the
base of carbon nanotubes. This is may be because of base growth
mechanism of carbon nanotubes where the metal nanoparticles remain
at the base of growing nanotubes. This can be also observed from the
micrographs shown in Figure 12. The diameter and length of carbon
nanotubes measured from these micrographs and comes out. to be -40
run and -15,000 nm respectively. This confirms the previous
measurements done with the help of SEM micrographs (Figure 4). The
rope like structure of bundles of carbon nanotubes can also be observed
from these micrographs.
The coating of nanomaterials and carbon nanotubes on the surface
of carbon fiber is to be carried out at a temperature of 400-1500°C. TGA
analysis of as-received carbon fiber, and coated carbon fiber is essential
to know the degradation behavior of these fibers with respect to
temperature and environment. The thermal analysis was carried out
under nitrogen and oxygen environments over a temperature range of 50-
900°C. The degradation behavior of as-received carbon fiber,
nanoparticles and carbon nanotubes coated carbon fiber in nitrogen
atmosphere is shown in Figure 13. There is a significant decrease in
weight loss of carbon fibers observed after coating of nanoparticles and
carbon nanotubes on its surface. It is decreased by -14% after the
coating of nanoparticles and carbon nanotubes as compared to weight
loss of as-received carbon fiber for the given temperature range of 900°C
and nitrogen environment. The coated carbon fibers degrade very slowly
through out the entire temperature range unlike the as-received carbon
libers, which degrades at a faster rate after 300°C. To find out the
degradation temperature where the rate of weight loss is maximum, a
derivative curve i.e. weight loss with respect, to time was measured and
shown in Figure 14. It shows the derivative (% weight/ minutes.) of asreceived
carbon fiber, and nanoparticles and carbon nanotubes coated
carbon fibers in nitrogen environment. The derivative curves for coated
carbon fiber is almost a straight line and no peak is observed in the
curves corresponding to these samples because the weight loss is
gradual and very less through out the given temperature range of 900°C
and environment (Figure 13).
The DTA analysis of all these samples i.e. as-received carbon fiber,
and nanoparticles and carbon nanotubes coated carbon fiber are shown
in Figure 15. The heat flow first increases with an increase of
temperature until a plateau is reached, i.e. the temperature of ~407"C for
as-received carbon fibers and then starts decreasing on further
increasing the temperature up to 900°C. The nature of degradation
reaction is endothermic but the peak for the curves corresponding to
nanomaterials and carbon nanotubes coated carbon fiber is shifted
toward left i.e., ~380°C as compared to the curves corresponding to asreceived
carbon fiber. The temperature corresponding to these peaks are
given in Table 2. It is also observed from, this Figure 15 that the area
enclosed by the curves corresponding to as-received carbon fiber is lower
than the area enclosed by the curves corresponding nanomaterials and
carbon nanotubes coated carbon fiber which suggests that the heat
required by nanoparticles and carbon nanotubes coated carbon fibers is
higher than as-received carbon fiber. This is may be because of the
presence of nanoparticles and carbon nanotubes on the surface of
carbon fiber in these samples. This requires extra heat to degrade these
samples which results in larger heat flow for these samples. The1 same
nature of heat flow curves indicates that the type of degradation reaction
is same.
The degradation reaction depends on the environment. To
understand the stability of nanomaterials and carbon nanotubes coated
carbon fiber, TGA analysis is carried out for as-received carbon fiber and
nanoparticles and carbon nanotubes coated carbon fiber in oxygen
atmosphere. The results are shown in Figure 16. The thermal stability is
more for nanomaterials and carbon nanotubes coated carbon fiber. The
starting degradation temperature is found to be ~600°C. The sudden
fluctuation in temperature is also found in TGA analysis of nanoparticles
and carbon nanotubes coated carbon fibers in oxygen atmosphere as
shown in Figure 16. The derivative of weight loss with respect to time as
a function of temperature for as-received carbon fiber and nanoparticles
and carbon nanotubes coated carbon fiber is shown in Figure 17. The
degradation temperature for as-received carbon fiber is observed at
~560°C in oxygen atmosphere. But the degradation temperature for
nanoparticles and carbon nanotubes coated carbon fiber is ~700°C. This
indicates the higher thermal stability of this coated fiber as compared to
as-received carbon fiber sample.
The DTA analysis of as-received carbon, fiber, and nanoparticles
and carbon nanotubes coated carbon fiber in oxygen environment is
shown in Figure 18. It follows the same endotherrnic trend as observed
earlier. The peak temperature is tabulated in Table 3.
A small secondary peak is also observed iri the heat flow curves.
This peak is due to the change in microstructure as shown in weight, loss
curves (Figure 16). To analyze this statement the heat flow data is
plotted with respect to time and shown in Figure 19. The nature of the
peak is same as shown in Figure 18.
To evaluate the performance of hybrid nanocomposite the dynamic
mechanical analysis was carried out. The analysis was done within a
temperature range of 30-170°C and at a frequency of 1 Hz under bending
mode. The variation of storage modulus with respect to temperature is
shown in Figure 20. A significant improvement is observed in storage
modulus for nanoparticles and carbon nanotubes coated carbon fiber
hybrid nanocomposite as compared to as-received carbon fiber
composites. The storage modulus for nanoparticles and carbon
nanotubes coated carbon fiber hybrid nanocomposite found to be
increased by -75% at a temperature of 30°C. The storage modulus
decreases with an increase in temperature but at any temperature the
storage modulus is higher for nanomaterials and carbon nanotubes
coated carbon fibers hybrid nanocomposites as compared to as-received
carbon fiber composites. Now the improvement in storage modulus is
explained with respect to the relative storage modulus. This relative
storage modulus is defined as the modulus ratio of coated to as-received
carbon fiber. Figure 21 shows the relative storage modulus of
nanoparticles and carbon nanotubes coated carbon fiber hybrid
nanocomposite with respect, to storage modulus of as-received, carbon
fiber. The relative storage modulus increases with increasing
temperature through out the temperature range of 90°C for
nanomaterials and carbon nanotube coated carbon fiber hybrid
nanocomposite respectively. Then it decreases with an increase in
temperature. The increase in modulus can be explained by the
increase in kinetic energy (G = v k T) where G, v, k and T are modulus,
cross link density, Boltzmann's constant and temperature respectively.
But the decrease in modulus with respect to temperature is due to the
decrease in intermolecular force of attraction in composite materials. In
addition to this the decrease of coefficient of friction between molecules
decreases the modulus value a higher temperatures.
The variation of loss modulus and relative loss modulus with
increasing temperature is shown in Figures 22 and 23 respectively. The
loss modulus for nanoparticles and carbon nanotubes coated carbon
fiber hybrid nanocomposite is higher than the as-received carbon fiber
composite at each, temperature. It is also observed that the loss modulus
reduces with increasing temperature for nanoparticles and carbon
nanotubes coated carbon fiber hybrid nanocomposite and as-received
carbon fiber composite. The same nature is also observed in relative loss
modulus data for all these composites (Figure 23).
Figure 24 shows the variation of Tan 8 with respect to temperature
for as-received carbon fiber composite, and nanoparticles and carbon
nanotubes coated carbon fiber hybrid nanocomposite. The value of Tan f>
first increases with an increase in temperature and then decreases on
further increasing the temperature. For as-received carbon fiber the Tan
8 increases up to a temperature of ~80°C and then starts decreasing as
temperature is further increased, whereas for nanoparticles and carbon
nanotubes coated carbon fiber hybrid nanocomposites it occurs at a
temperature of ~65°C. The peak corresponding to this temperature is
glass transition temperature (Tg). The glass transition temperature of all
these composites has been listed in Table 4. It is observed from the
Table 4 that the glass transition temperature of polyester carbon fiber
composite deceases after the coating of nanoparticless and carbon
nanotubes on the surface of carbon fiber.
Main advantages of the Invention;
Advantage 1: This is the first time in the world we have prepared hybrid
nanocomposites using long carbon fiber coated with nanomaterials i.e.
various type of metals, i.e., cobalt (Co), nickel (Ni), ruthenium (Ru),
rhodium (Rh), palladium (Pd), iridium (Ir), platinum (Pt) chromium (Cr),
tungsten (W); and carbon nanotubes on the surface of carbon fiber and
going to report in the literature.
Advantage 2: In case of conventional composite materials it is very
tough/difficult to disperse the nanomaterials in the matrix. If it is carbon
nanotube again it is difficult due to its lightweight. Keeping this in mind
we have developed a process where distribution of nanomaterials and
carbon nanotube is uniform through out the surface of carbon fiber. This
carbon nanotube coated carbon fiber could be used to make any
composite materials for structural application.
Advantage 3: It is possible to get a uniform coating of nanoma.teria.ls
i.e., cobalt (Co), nickel (Ni), ruthenium (Ru), rhodium (Rh), palladium
(Pd), iridium (Ir), platinum (Pt) chromium (Cr), tungsten (W) on the
surface of individual long carbon fiber in the range of 1 to 80 nm.
Advantage 4: Even though it is possible to get a uniform coating of
mixed nanomaterials i.e., combination of any two of the following metals,
i.e., cobalt (Co), nickel (Ni), ruthenium (Ru), rhodium (Rh), palladium
(Pd), iridium (Ir), platinum (Pt) chromium (Cr), tungsten (W) on the
surface of individual long carbon fiber in the range of 1 to 80 nm.
Advantage 5: It is possible to get a uniform coating of carbon
nanotube on the surface of individual long carbon fiber in the density
range of 1 to 90%.
Advantage 6: It is possible to get a uniform coating of carbon
nanotube on the surface of individual long carbon fiber in the density
range of 1 to 80%.
Advantage 7: The length of carbon nanotubes on the surface of carbon
fiber can be varied within the range of 10 to 20,000 nm.
Advantage 8: The diameter of carbon nanotubes on the surface of
carbon fiber within the range of 1 to 40 nm.
Advantage 9: The carbon nanotube grown on the surface of carbon fiber
is helical in structure. This helical structure helps to improve the strain
at breaking point of composite materials. This is again another
breakthrough.
Advantage 10: The thermal stability of nanomaterial and carbon
nanotube coated carbon fiber has been improved significantly. 1.5%
weight loss is observed when the carbon fiber is coated with carbon
nanotube in the temperature range of 25 to 900°C in nitrogen
atmosphere where as 16% in the uncoated carbon fiber.
Advantage 11: The storage modulus of hybrid nanocomposites prepared
by carbon nanotube coated carbon fiber at room temperature, i.e., 25°C
is improved by 75% with respect to the uncoated carbon fiber. Where as
at high temperature, i.e., 150°C the improvement is 300% with respect to
the uncoated carbon fiber's composites.
Advantage 12: Generally storage modulus decreases with increasing
temperature. This is a conventional fact in case of all composite
materials. But when the carbon fiber is coated with nanomaterials and
carbon nanotube, storage modulus increases with increasing
temperatures upto 100°C.
Advantage 13: 50% improvement in loss modulus is observed in hybrid
nanocomposites when the carbon fiber is coated with carbon nanotube.
Advantage 14: 50% improvement in damping is observed in hybrid
nanocomposites when the carbon fiber is coated with carbon nanotube.
Advantage 15: The glass temperature of hybrid nanocomposite is shifted
to the high temperature, ie., from 65 to 85°C when the carbon fiber is
coated with carbon nanotube.
Advantage 16: This fabrication process of hybrid nanocomposites is an
insitu process. As it is insitu process, this technique does not require
any mixer, which is very costly equipment in conventional process.
Advantage 17: The processing cost is less as it does not require mixture
compared to the conventional process.
Advantage 18: The new technique has a great potential in the
manufacture of fiber reinforced nanocomposites for high tech
applications, i.e., aerospace, automobile, etc.
This new hybrid nanocomposites has promise for wide range of
applications, viz., automobile, aircraft, space craft, sports, etc.
ddering the current and future needs it is the interest to initiate a
ig research programme in this area to foster the industries to adopt
;r processing routes for manufacturing their products with superior
ifications and also introduce new products based on unique
ierties of this class of new generation materials. Again due to the
lability of various types of high molecular weight polymers, in near
re this advanced hybrid materials is likely to increase the production
her reinforced plastic components satisfactorily. This will in turn
ance the interest of laboratories and industries. Further, fiber
forced plastic technology is labor incentive and India is in a much
er shape to compete with developed countries
main advantage of this invention is that use can be made of the
standing mechanical properties of carbon nanotubes i.e. Young's
lules of-1.25 TPa, and Tensile strength of -100 GPa in a structural hybrid
icomposites. In this invention it does not need to add carbon nanotube during the
cation of nanocomposite in the polymer matrix which is much more difficult to
disperse in the matrix. In addition to this the carbon nanotube is grown on the surface of
carbon fiber, i.e. it is an insitu process. The resulting hybrid nanocomposite shows
excellent thermal stability and mechanical properties.
It is to be understood that the process of the present invention is
susceptible to modification, changes, adaptations by those skilled in the
art. Such modifications, changes adaptations are intended to be within,
the scope of the present invention which is further set forth under the
following claims:

WE CLAIM;
1. A nanomaterial and carbon nanotube coated carbon fiber reinforcedpolymer
hybrid nanocomposite comprising supported material, which
is coated with a carbon product comprising carbon nanotubes and
nanomaterials, and a polymer matrix material.
2. A process for preparation of a nanomaterial and carbon nanotube
coated carbon fiber reinforced-polymer hybrid nanocomposite
comprising the steps of :
a. heating the carbon fiber at a temperature of 100-600°C for a time
period of 60-1800 second, coating of catalyst on the surface of carbon
fiber followed by heating the catalyst coated carbon fiber in an oven at a
temperature of 50-200°C for a period of 100 to 10,000 seconds.
b. keeping of catalyst coated fabric or fiber loaded quartz boat in
the mid zone of a reactor as herein described,
- connecting the reactor to a vacuum line to pump down to less
than 200 mm Hg
incorporation of the gases into the mixing chamber and
subsequently in reactor
- de-oxygenation of the gases followed by removal of moisture
- growth of nanomaterial and carbon nanotubes under different
conditions as herein described.
c. fabrication of hybrid nanocomposite comprising the steps of:
-mixing of curing agent, also known as hardner in a resin, also
known as polymer in a ratio of 100:0.2 to 100:5 at a temperature of 10 to
50°C
-mixing of accelerator, also known as catalyst with solvent in a
mixture of resin and hardner in ratio of 100:0.2 to 100:5 at a
temperature of 10 to 50°C
-dipping the nanomaterial and carbon nanotube coated fiber in
the mixture of resin, hardner and catalyst and keeping in the mould to
get a shape of mould known as preform,
- loading of the perform in hydraulic press and curing at a
pressure of 1 to 10 kg/cm2, and temperature of 25-100°C for a period of
1-24 hours.
3. A process for preparation of a nanomaterial and carbon nanotube as
claimed in claim 2 wherein the carbon fiber is heated in an atmosphere
of air, nitrogen, oxygen, Argon, Hydrogen, CO2 and mixtures thereof.
4. A nanomaterial and carbon nanotube and a process for preparation
thereof as claimed in claim 1 and 2 wherein the carbon fibers are rayon
based, polyacrylonitrile based and pitched based.
5. A carbon nanotube and nanomaterials, and a process for preparation
thereof as claimed in claim 2 wherein the catalyst is selected from Group
VIII metals consisting of Ni (Nickel), Ru (Ruthenum), Rh (Rhodium), Pd
(Palladium), Ir (Iridium) and Pt (Platinum) and/or mixture thereof, Group
VIb metals consisting of Cr (Chromium), Mo (Molybdenum) and W
(Tungsten) and/or mixture thereof, and mixture of group VIII metals
consisting of Ni (Nickel), Ru (Ruthenium), Rh (Rhodium), Pd (Palladium),
Ir (Iridium) and Pt (Platinum) and Group VIb metals consisting of Cr
(Chromium), Mo (Molybdenum) and W (Tungsten).
6. A carbon nanotube and nanomaterials, and a process for preparation
thereof using mixed catalyst as claimed in claim 5 wherein the catalyst is
comprising at least one group VIII metal and at least one group VIb metal
in a ratio of one part of Cr or other metal from group VIb and at least 2
or more part of Ni or other metal from group VIII
7. A process for preparation of a carbon nanotube and nanomateria! as
claimed in claim 2, wherein the oxidizing agents used in dip coating are
metal, metal sulfide, metal disulifide, metal halide and metal sulphate in
which metals are group VIII metals consisting of Ni, Ru, Rh, Pd, Ir, and
group VIb metals consisting of Cr, Mo, W and mixture thereof reducing
agents are group of metal consisting of Na, Mg, Al, Zn, Cu and mixtures
thereof, metal hydrides consisting of Na, Mg, Al, Zn, Cu and mixtures
thereof, metal hypophosphite consisting of Na, Mg, Al, Zn, Cu
and mixtures thereof and chelating agents are consisting of water,
carbohydrates, including polysaccharides, organic acids with more than
one coordination group lipids, steroids, amino acids and relates
compounds, peptides, phosphate, nucleotides, tetrapyrrois,
ferrioxamines, ionophores, such as gramicidin, monensin, valinomycin,
phenolics, 2, 2'-bipyridyldimercaptopropanol, ethylenedioxy-diethylenedinitrilo-
tetraacetic acid, ethylene,glycol-bis(2-aminoethyl)-N,N.N',N"-
tetraacetic acid, lonophores-nitrilotrriacetic acid, NTA ortho-
Phenanthroline, salicylic acid, triethanolamine, sodium succinate,
sodium acetate, ethylene diamine, ethylenediaminetetraacetic acid,
dethylenetriaminepentaacetic acid, ethylenedinitrilotetraatic acid, and
mixture thereof.
8. A process for preparation of a nanomaterial and carbon nanotube as
claimed in claim 2, wherein the buffer solution used in dip coating is
group of week acid and its salt and mixture thereof in which week acids
consisting of succinic acid formic acid acetic acid, tricholoroacetic acid,
hydrofluoric acid, hydrocynic acid, hydrogen sulphide, water and group
of sodium and/or potassium consisting of succinic acid, formic acid,
acetic, trichoroacetic acid, hydrofluoric acid, hydrocynic acid and
hydrogen sulphide.
9. A process for preparation of nanomaterial and carbon nanotube as
claimed in claim 2, wherein the coating of the catalyst is done in an
environment of nitrogen, argon, helium and mixture thereof and at a
temperature of 10-125°C for a time period of 10-3600 second to obtain a
thickness of 50-200 nm.
10. A process for the preparation of nanomaterial and carbon nanotube
as claimed in claim 2, the gases comprise carbon containing gas such as
group of saturated hydrocarbons, aliphatic hydrocarbons, oxygenated
hydrocarbons, aromatic hydrocarbons, alcohols, carbon monoxide and
mixture thereof, reducing gas such as group of gases consisting of
hydrogen, chlorine and mixtures thereof and diluent gas such as group
consisting of nitrogen, argon, helium and mixture thereof and the ratio of
these gases are 0:100 to 50: 50, 0:5:95 to 60:20:20 and 0:100 to 60:40
between reducing:diluent gases, carbon containing gas:reducing
gas:diluent gas, and carbon containing gas:diluent gas respectively.
11. A process for preparation of a nanomaterial and carbon nanotube as
claimed in claim 2 wherein the nanomaterial is formed at a temperature
range of 400 to 900°C in a time period of 10 to 7200 sec, which has a
diameter of 1 to 80 nm, wherein at least 20% has a diameter less than 30
nm, and the carbon nanotube is formed at a temperature range of 650-
1500°C in a time period of 10 to 3600 sec, which has a diameter of 1 to
60 nm and length of 9000 to 20000 nm, wherein at least 70% of the
carbon nanotubes have diameter less than 40 rim and 40% carbon
nanotubes are single wall.
12. A nanomaterial and carbon nonotube coated carbon fiber reinforcedpolymer
hybrid nanocomposite and a process for preparation thereof as
claimed in claim 1 and 2 wherein the polymer is thermosetting resin
consisting of polymide, polyester, polyrre thane, polysulfonamide,
polycarbonate, polyurea, polyphosphonoamide, polyarylate, polyimide,
poly (amic ester), poly (ester amide), poly(enaryloxynitrile) matrix and/or
mixtures thereof.
13. A nanomaterial and carbon nonotube coated carbon fiber reinforcedpolymer
hybrid nanocomposite and a process for preparation thereof as
claimed in claim 12 wherein the polyester is a copolymer of acid
consisting polyester of terephthalic acid, isophthalic acid, pruhalic acid.
trimellitic acid, pyromellitic acid, hexahydrophthalic acid, adipic acid or
sebacic acid and diol consisting of 1,2-ethanediol, 1,2-propanediol,
trimethylolpropane, neopentyl glycol, 1,3-butanediol, 1,4,-butanediol,
pentaerythritol, glycerol, tris(hydroxyethyl) isocyanurate or ethoxylated
bisphenol A.
14. A nanomaterial and carbon nonotube coated carbon fiber reinforced-polymer hybrid
nanocomposite and a process for preparation thereof as claimed in claim 13, wherein the
polyester has an acid number in the range 1 to 150 mg KOH per gram, hydroxyl number
less than 30 mg KOH per gram, number average molecular weight (Mn) is less than 2000
and viscosity in the range of 12000-15000 cP.
15. A process for preparation of nanomaterial and carbon nonotube
coated carbon fiber reinforced-polymer hybrid nanocomposite as claimed
in claim 2, wherein the curing agent is temperature activatable selected
from group consisting of benzoyl peroxide, dicumyl peroxide, hydrogen
peroxide, methyl peroxide, ethyl peroxide, methyl ethyl ketone peroxide,
sulphur and mixture thereof and the mixing of curing agent, in polymer is
done at 20-100°C.
16. The nanomaterial and carbon nonotube coated carbon fiber
reinforced-polymer hybrid nanocomposite according to Claim 2, wherein
the organometallic compound acts as an accelerator suitable for peroxide
curing of an unsaturated polyester resin is present in an amount
between 2 and 10 per cent by weight based on weight of resin, wherein
the organometallic compound consists essentially of one or more cobaltcontaining
salts selected from the group consisting of cobalt octoate,
cobalt 2-ethylhexanoate, and cobalt naphtenate, one or more solvents,
and, optionally, one or more stabilizers, wherein the solvents are selected
from the group consisting of pentane, isopentane, hexane,
diethyleneglycol,dipropyleneglycol, ethyleneglycol, isobutanol, peiitanol,
triethylphosphate, triethylphosphite, dibutylmaleate, dibutylsuccinate,
and ethylacetate.
17. The naiiomaterial and carbon nonotube coated carbon fiber
reinforced-polymer hybrid nanocomposite according to Claim 16 wherein
the solution comprising 20 to 99% w/w of solvent (s), and 1 to 80% w/w
of cobalt-containing salt (s), and optionally 0.1-8%w/w of stabilizer (s),
up to a total of 1 00% w/w.
18. A method of manufacturing nanomaterial and carbon nanotube
coated carbon liber reinforced-polymer hybrid nanocomposite as claimed
in Claim 2, wherein nanoparticle and carbon nanotube coated support
materials are added at 2-60% by volume to said mixture of polymer
matrix, curing agent and accelerator prior to said polymer being cured.
19. A process for preparation of nanomaterial and carbon nanotube
coated carbon fiber reinforced-polymer hybrid nanocomposite as claimed
in claim 2, wherein the curing step is carried out below the degradation
temperature of polymer i.e., at a temperature of 25-100°C, under a
pressure of about 1 to 10 kg/cm2 and for a period of 1-24 hours.
20 A process as claimed in claim 2 wherein coating of the catalyst is
done at a temperature of 10 to 125°C for a period of 10 to 3600 seconds
by dipping the carbon fiber in acidic bath provided in a dip-coating setup
wherein the bath is prepared by dissolving oxidizing agent in deionized
water, in a ratio of 1:100 to 9:100 which is added with reducing
agent, chelating agent and buffer in a ratio of 1:1 to 1:5, 1:1 to 1:10 and
1:0.10 to 1:1 followed by stirring of the mixture to obtain the acidic bath.
22. A process as claimed in claim 2 wherein the coating of the
catalyst is done by spraying a brown coloured solution on carbon fiber
wherein the preparation of the solution comprises the steps of:
-dissolving metal nitrate in de-ionized water in a ratio of 1:5 to
1:15 which is added with equal amount of carbonate to obtain a brown
coloured solution
stirring of the solution so obtained to get a semi solid mass
followed by heating the same in an oven at a temperature of 75 to 200°C
for a period of 1000 to 86400 seconds
heating the resulting mass thus obtained in a furnace at a
temperature of 300 to 700°C for a period of 1000 to 7000 seconds
followed by cooling down the same to room temperature to obtain a
brown coloured mass
addition of methyl alcohol with the powder followed by
stirring to obtain the solution.
23. A nanomaterial and carbon nanotube coated carbon fiber reinforcedpolymer
hybrid nanocomposite as claimed in claim 1 wherein the
nanocomposite comprises
carbon fiber varied from 1 to 60 wt%
polymer varied from 99 to 40%
carbon nanotube varies from 1 to 70 wt% with respect to
carbon fiber (excluding all other composition)
accelerator (catalyst) in composites varies from 100:0.2 to
100:5 (resin:catalyst)
curatives (hardner) varies from 100:0.2 to 100:5
(resin:hardner) and
nanoparticles varies from 1 to 15% based on carbon
nanotube.
24. A nanomaterial and carbon nanotube coated carbon fiber reinforcedpolyrner
hybrid nanocomposite and a process for preparation of a carbon
nanotube coated carbon fiber reinforced-polymer hybrid nanocomposite
substantially as herein described with reference to accompanying
drawings.

Documents:

1813-del-2005-Abstract-(10-10-2012).pdf

1813-del-2005-abstract.pdf

1813-del-2005-Claims-(10-10-2012).pdf

1813-del-2005-claims.pdf

1813-DEL-2005-Correspondence-others (01-03-2007).pdf

1813-del-2005-Correspondence-Others-(10-10-2012).pdf

1813-del-2005-correspondence-others.pdf

1813-del-2005-description (complete).pdf

1813-del-2005-drawings.pdf

1813-del-2005-form-1.pdf

1813-DEL-2005-Form-18 (01-03-2007).pdf

1813-del-2005-form-2.pdf

1813-del-2005-form-26.pdf

1813-del-2005-Form-3-(10-10-2012).pdf

1813-del-2005-GPA-(10-10-2012).pdf

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Patent Number

258293

Indian Patent Application Number

1813/DEL/2005

PG Journal Number

52/2013

Publication Date

27-Dec-2013

Grant Date

27-Dec-2013

Date of Filing

14-Jul-2005

Name of Patentee

INDIAN INSTITUTE OF TECHNOLOGY

Applicant Address

INDIAN INSTITUTE OF TECHNOLOGY, KANPUR, INDIA.

Inventors:

#	Inventor's Name	Inventor's Address
1	KAMAL KRISHNA KAR	DEPARTMENT OF MECHANICAL ENGINEERING AND MATERIALS SCIENCE PROGRAMME INDIAN INSTITUTE OF TECHNOLOGY, KANPUR, INDIA.
2	PRASHANT KUMAR	DEPARTMENT OF MECHANICAL ENGINEERING AND PROGRAMME INDIAN INSTITUTE OF TECHNOLOGY, KANPUR, INDIA.
3	NG RAMAKANTH IYENGER	DEPARTMENT OF AEROSPACE ENGINEERING INDIAN INSTITUTE OF TECHNOLOGY, KANPUR, INDIA.
4	PRABHAT KUMAR AGNIHOTRI	MATERIALS SCIENCE PROGRAMME INDIAN INSTITUTE OF TECHNOLOGY, KANPUR, INDIA.

PCT International Classification Number

B82B1/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA