|Title of Invention||
"DEVICE FOR PRODUCING SINGLET OXYGEN"
|Abstract||Device for Producing Singlet Oxygen, comprising a housing (1) forming a chamber which has two opposite surfaces, one surface covered by a coating made dye excitable by light source (3) light emitting diodes for irradiating the surfaces (6) and other transparent surface (4) covered by a glass or plastic (thermoplastic) or acrylic sheet and uniformly a thin layer of dye adhesive comprising a finely roughened surface introduced by polishing. The depth of the indentations or pores determines the thickness of the layer of dye. The light emitting diodes are located in a spectral region to the absorption peak between 600nm - 680nm.|
|Full Text||DEVICE FOR PRODUCING SINGLET OXYGEN
This invention relates to a device for producing singlet oxygen of the type mentioned in the preamble of claim 1 as well as to a method for producing a surface coated with a dye for such device.
Such device for producing a Singlet Oxygen is known from the WO 9729044 -which shows a structure comparable to that of figure 1 of the present application. With this apparatus, a chamber is formed having two surfaces, one of these surfaces being the transparent, whereas the other surface is covered by coating made from a dye excitable by light radiation. This surface coated with the dye is irradiated with light from a light source disposed adjacent to the transparent surface. The light source is preferably a halogen lamp, and the transparent surface filters out a certain part of the radiation, such that a radiation having a predetermined frequency is obtained. This light radiation acts upon the dye disposed on the surface coated with the dye and the oxygen flowing over this surface is brought into an excited condition for forming singlet oxygen. The dye coating is applied by a kinetic, thermal or chemical methods on a finely roughened surface or a microporous surface. The efficiency of this apparatus is only low, and the production of the dye coated surface is quite expensive and further large amounts of heat are produced by the use of the halogen lamp.
The document in WO 9729044 proposes the use of natural light or artificial light, preferably a halogen lamp. It is proposed to cover the halogen lamp with a glass cover eliminating a certain portion of the light to achieve radiation within a specific frequency pattern. No hint is given to the use of light emitting diodes having a light emission comprising a wavelength located within the range of maximum radiation absorption of the dye. Such light emitting diodes were available long time before the filing date of the document, but in spite of this, in the document it was obviously considered that the light output of light emitting
diodes would be insufficient so that the halogen lamps with higher light output and a corresponding high heat dissipation have been used which of course is disadvantageous.
This document, while teaching the use of a microporous surface similar to the present invention, there is no hint to use the step of polishing and applying pressure for introducing the dye into the micropores. This document further teaches a coating by application of the chromophore particles by "kinetic, thermal or chemical methods". This "kinetic methods" only might be compared with the subject matter of original claims 15 and 16 of the present invention and are used with the present invention only for preparing the surface for the inventive step of polishing and thereby applying pressure to the chromophore particles on the surface, such that the depths, such that the depth of the indentations or the micropores determines the thickness of the layer of dye. This reduced thickness of the layer of chromophores increases the efficiency and allows the use of lower levels of light irradiation and therefore the use of light emitting diodes. Further, an exact control of the thickness of the layer of chromophores is made possible.
US- Patent 4 579 837- is further known to deposit on a substrate several layers of polycristaline organic dye, like for instance trypaflavin, eosine or tetracene. Also in this case the production of the surface covered with dye is quite expensive.
The object of invention is to provide a device as well as a method of the type mentioned above, which allows the production of singlet oxygen with high efficiency and low expense.
This problem is solved by the features set out in claims 1 and 4 respectively. Advantageous developments and embodiments of the invention are set out in the respective sub claims.
With the device according to the invention, a single layer of the dye is introduce into the pores on the surface of the substrate by exerting the pressure and friction,
said surface being finely roughened and the dye being introduced by polishing it into the indentions of the finely roughened surface. The depth of the indentions or pores determines the thickness of the layer of dye. In this manner, the effort for producing the surface covered with dye is quite low. Further with this method, the characterstics of the dye are not impaired.
The excitation of the dye is performed preferably by light emitting diodes having an emission wavelength adapted to the absorption peak of the respective dye, this absorption peak lying, with most of the dyes mentioned below, mostly in the region of 600 through 680 nm, a region for which light emitting diodes having a relatively narrow wave length emission are commercially available.
Since the conventional light emitting diodes maybe used for exciting the dye, on one hand, a simple and cost effective structure is obtained and on the other hand, a high total efficiency of the device is obtained in view of the high efficiency of light emission of such light emitting diodes.
The dye may be for instance blue and green phthalocyanine, methylene blue, rose Bengal, porphyrine (Zinc tetraphenylporphyrin) or eosin.
The substrate may preferably be a glass or acrylic glass disc or even a metal disc having an insulated surface, preferably an anodized aluminum disc.
For its uniform distribution, the dye may be dissolved in a solvent and may be uniformly distributed on the surface within an electromagnetic field, or the substrate may be electrostatically charged and exposed to a dye mist.
For obtaining the recessed or pores, the substrate may be roughened in a sand blast procedure.
The invention will be explained in more detail with reference to embodiments
shown in the drawings, wherein :
Figure 1 is an embodiments of the device for the activation of air.
Figure 2 is an embodiment of the device for activating liquids.
The embodiments of the device shown in figure 1 comprises a housing which in the embodiment shown has a cynical section, but may also be elongated or may have any other cross section. This housing forms a chamber bounded by a first surface (4) formed by a covering glass plate or any other light transparent plate, as well as by a surface (6) coated with a dye, and a air guide and / or a spacer (5) may be disposed to obtain an intimate contact between the oxygen or the oxygen containing gas guided through the chamber and the coated surface (6).
On the side of covering glass plate (4) opposite to the coated surface (6), a printed circuit board (2) is disposed, which carries light emitting diodes (3), which illuminate the dye on the surface (6) via the covering glass plate (4).
The surface (6) is coated with dye by taking this surface as an upper surface of a substrate which is finely roughened and thereby provided with micropores into which the dye is polished by exerting pressure.
For obtaining a uniform distribution of the dye on the coated surface (6), the dye either may be dissolved in an appropriate solvent and then uniformly distributed on the surface within an electromagnetic field or the substrate is electrostatically and is exposed to a dye mist, whereby the electrostatic charge attracts the dye powder, such that also a uniform thin distribution of the dye particles on the surface is obtained.
In both cases, the surface subsequently is polished such that a stable and uniformly thin adhesion of the dye on the finely roughened surface is obtained.
As a dye, specially, phthalocyanine, porphyrine (Zinc tetraphenylporphyrine) and eosine are useful. These dyes have a wavelength region of peak absorption between about 600 nm and light emitting diodes having a light emission in this wavelength are without any problem commercially available. The excitation peak
of singlet oxygen into its base state, is at 634.3 nm. The excitation energy for the oxygen preferably should have a wavelength somewhat shorter than the 634.3 nm.
On the dye surface excited by the light radiation from the light emitting diodes, exitonic hits against the oxygen molecules are produced, which are contained within the gas fed through chamber, the peripheral electrons of the oxygen molecules reacting with the jumps to the next incompletely occupied electron orbits, such that a singlet oxygen condition results.
The gas containing oxygen or pure oxygen may be fed to the chamber formed between the covering plate 4 and the surface 6 coated with the dye by means of an inlet 7 and may be removed via an outlet 8 as shown in figure 1.
In the embodiment shown in figure 2, the gas inlets and gas outlets are omitted and a light transparent substrate is used over which a gas containing oxygen is disposed. The side of the substrate which is not coated with the dye is in direct contact with the surface 9 of a body or with a liquid which shall be exposed as exitons produced in the dye by the light radiation.
DE 19 835 456- is quite different from the present application, it describes the use of a molded body containing a photosensibilator which is embedded into a polymetric matrix. No hint is given to use a substrate comprising a finally roughened surface into which the dye is introduced by polishing. This document describes the use of optical fiber 2 being covered at its distant end with a layer 3 containing a photo sensibilisator. The photosensibilsators comprises several compositions which are partly similar to the photo sensibilisator or dyes indicated in claim 3 through 9 of the present invention.
US4 921 589 - is similar to DE 19 853 457 and hence uses a polymetric matrix containing a photo sensitiser.
The US examiner additionally cited the US patent 4 302 480, which is even more distant from the present invention then all other documents. This particular document US patent 4 302 480, teaches applying a coating of staining material on
a thin cover sheet " of a nature such that as far as possible no reagents are
absorbed therein or held fast thereto". This in contrary to the present invention wherein the carrier has a surface provided with micropores so that the dye is at least partially absorbed and held fast thereto. This document would not allow the polishing step of the present invention since the solution of colorant of this document would simply wiped of the thin sheet on trying to polish it.
In summary none of the citation does give any hint to the polishing step which has the benefit that a very thin layer of the dye is introduced which is readily exited by lower levels of light emission such as may be produced by light emitting diodes.
We Claim :
1. A device for producing singlet oxygen, comprising a housing (1) forming a chamber which has at least two opposite surfaces, one (4) of these surface being transparent, characterized in that other surface (6) is roughened to form indention or micropores into which a dye excitable light is introduced a light source (3) for irridiation the other surface (6) covered with said dye is covered by a coating made of a dye excitable by light and a light source (3) for irradiating the other surface (6) covered with the dye, wherein said other surface covered with dye wherein the said light source is formed by light emitting diodes (3) whose light emission comprises a wavelength located within the range of maximum radiation absorption of the dye of the coated surface (6) coated with the said dye.
2. Device according to claim 1, wherein said dyes are reflected from one or more of Phthalocyanine, Green Phthalocyanine, Blue Phthalocyanine, Methylene Blue, Methylene Blue, Zinc Tetraphenylporphyrin and Eosin.
3. Device as claimed in any preceding claim, wherein the light emission of the light emitting diodes is located in a spectral region between about 600nm and 680 nm.
4. Device as claimed in any preceding claim, wherein the said substrate comprises a glass or plastic or acrylic glass disc.
5. Device as claimed in any preceding claim, wherein the said substrate comprises a glass disc.
6. Device as claimed in any preceding claim, wherein the said substrate comprises an anodized aluminum plate.
7. A method for producing a dye coated surface for a device for producing singlet oxygen as claimed in any preceding claim comprising of a housing characterized in that said method comprises the steps of providing a
substrate with finely roughened surface to form micropores uniformly distributing a dye on said finely roughened surface and introducing the dye into the micropores of the finely roughened surface by exerting pressure and polishing.
8. A method as claimed in any preceding claim, wherein the step of uniformly distributing the dye comprises of dissolving the dye in a solvent and uniformly distributing the dissolved dye on the said surface within an electromagnetic field.
9. A method as claimed in any preceding claim, wherein the step of uniformly distributing the dye comprises of electrostatically charging the substrate and exposing the substrate to a dye mist.
10. A method as claimed in any preceding claim, wherein a plastic material disc is used as substrate and is finely roughened by a sand blasting method to form the indentations or micropores.
|Indian Patent Application Number||646/DELNP/2003|
|PG Journal Number||22/2011|
|Date of Filing||28-Apr-2003|
|Name of Patentee||NATURAL ENERGY SOLUTIONS AG.|
|Applicant Address||REISERTSTASSE 21, D-53773 HENNEF, GERMANY.|
|PCT International Classification Number||C01B 13/02|
|PCT International Application Number||PCT/EP01/11255|
|PCT International Filing date||2001-09-28|