System And Method For Treating Microorganisms

Abstract

A system for the treatment of microorganisms includes: a textile web having optical fibers in warp and/or weft woven with binding threads in warp and/or weft, each of the optical fibers having invasive alterations along the fiber and allowing the emission of light propagating in the fiber at these alterations; a light source arranged opposite one or both free ends of the optical fibers. The textile web includes metallic warp and/or weft threads woven with the binding threads, the metallic threads being based on a metal having a negative effect on the growth of microorganisms. The light source generates a light beam having at least one wavelength in the visible or ultraviolet spectrum.

Claims

1. A system for the treatment of microorganisms comprising: a textile web comprising optical fibers in warp and/or weft woven with binding threads in warp and/or weft, each of the optical fibers having invasive alterations along the fiber and allowing the emission of light propagating in the fiber at these alterations; a light source arranged opposite one or both free ends of the optical fibers characterized in that the textile web further comprises metallic warp and/or weft threads woven with said binding threads, said metallic threads being based on a metal having a negative effect on the growth of microorganisms, the negative effect comprising the inactivation of the microorganisms or the reduction of their microbial activity; and in that the light source generates a light beam comprising at least one wavelength in the visible or ultraviolet spectrum.

2. The treatment system according to claim 1, wherein the light source generates type A ultraviolet radiation or radiation with a wavelength of between 315 nm and 400 nm.

3. The treatment system according to claim 1, wherein the light source generates near UV visible radiation or with a wavelength of between 400 nm and 500 nm.

4. The treatment system according to claim 1, wherein the metal threads are made of material having antimicrobial properties.

5. The treatment system according to claim 1, wherein the metal threads are made of a material selected from the group comprising silver and copper.

6. The treatment system according to claim 1, wherein the textile web has two opposite visible surfaces, and in which optical fibers and metal threads held by binding threads are visible on the two opposing sides of the web.

7. The treatment system according to claim 1, wherein the textile web comprises a superposition of textile layers, each layer being formed of optical fibers and metal threads held by binding threads.

8. The treatment system according to claim 1, wherein the textile web has two opposite visible surfaces, and in which the optical fibers are visible on one of the surfaces, and the metal threads are visible on the other surfaces.

9. The treatment system according to claim 1, wherein the textile web has two opposite visible surfaces, and in which the optical fibers are visible on one of the surfaces, and the metal threads are visible on both surfaces.

10. The treatment system according to claim 1, wherein the textile web has two opposite visible surfaces, and in which the optical fibers are visible on the two surfaces, and the metal threads are visible on one of the two surfaces.

11. The treatment system according to claim 1, wherein the textile web further comprises a coating layer incorporating photocatalytic particles deposited on all or part of the optical fibers and/or on all or part of the binding threads, before weaving the optical fibers and the binding threads.

12. The treatment system according to claim 1, wherein the textile web further comprises a coating layer incorporating photocatalytic particles deposited on all or part of at least one of the surfaces of the fabric formed by the optical fibers and binding threads.

13. The treatment system according to claim 12, wherein the photocatalytic particles are formed from a material selected from the group consisting of titanium dioxide, zinc oxide, zirconium dioxide, and cadmium sulfide.

14. A method for treating microorganisms in a liquid or gaseous medium, comprising: placing the textile web according to claim 1 in the said medium; and illuminating the free ends of the optical fibers with said light source.

Description

BRIEF DESCRIPTION OF FIGURES

[0052] Other characteristics and advantages of the invention will become clear from the following description, given with reference to the attached drawings and which is indicative and not limiting, in which:

[0053] FIG. 1 is a perspective view of a textile web according to any embodiment of the invention;

[0054] FIGS. 2A-2G are cross-sectional views of the textile web according to different variants in the arrangement of the optical fibers and of the metallic threads;

[0055] FIG. 2A is a cross-sectional view of the textile thread according to a variant in which the optical fibers and metal threads are woven so as to be visible on both surfaces of the textile web;

[0056] FIG. 2B is a cross-sectional view of the textile thread according to another variant in which the optical fibers and the metal threads are woven in such a way as to be visible on both surfaces of the textile web;

[0057] FIG. 2C is a cross-sectional view of the textile web according to a variant in which the optical fibers and the metal threads are woven in such a way as to be visible on a single surface of the textile web;

[0058] FIG. 2D is a cross-sectional view of the textile web in another variant in which the optical fibers and metal threads are woven so as to be visible on different surfaces of the textile web;

[0059] FIG. 2E is a cross-sectional view of the textile web according to another variant in which the metal fibers are visible on both surfaces and the optical fibers are visible only on one surface of the textile web;

[0060] FIG. 2F is a cross-sectional view of the textile web according to another variant in which the optical fibres are visible on both surfaces and the metal threads are only visible on one surface of the textile web;

[0061] FIG. 2G is a cross-sectional view according to another variant in which a textile web based on optical fibres is combined with another textile based on metal threads;

[0062] FIG. 3 is a schematic representation of the textile web in use;

[0063] FIG. 4 is a graphical representation showing the antimicrobial effect of the textile web provided with copper and/or silver metal threads;

[0064] FIG. 5 is a graphical representation showing the antimicrobial effect of copper combined or not with TiO.sub.2;

[0065] FIG. 6 is a graphical representation showing the antimicrobial effect of the textile web in a gaseous medium.

[0066] It will be noted that in these figures, the same references designate identical or similar elements, and the various structures are not to scale. Furthermore, only the essential elements for understanding the invention are shown in these figures for reasons of clarity.

DETAILED DESCRIPTION OF THE INVENTION

[0067] The treatment solution of the invention is described below, by way of non-limiting example, in the specific case of an antimicrobial treatment. according to any embodiment of the invention, the treatment solution therefore comprises a textile web obtained by weaving optical fibers, metallic threads, and binding threads. The end of the optical fibers is coupled to a light source configured to generate UV radiation.

[0068] The textile web 1 according to any embodiment is illustrated in FIG. 1 and therefore incorporates side-emitting optical fibers 2 and metallic threads 4 having in particular antibacterial and/or antimicrobial properties. The optical fibers 2 and the metal threads 4 extend parallel to each other.

[0069] These optical fibers 2 and these metallic threads are arranged in warp and/or weft and are woven with binding threads 3 arranged in warp and/or weft. The ends 6 of the optical fibers 2 are intended to be arranged facing a light source 7 configured to generate ultraviolet radiation, in particular of the UV-A type.

[0070] In practice, the binding threads may be woven according to a plain-type weave which provides optimum mechanical strength and surface uniformity. Other types of weaving may be envisaged, such as satin, twill or other. The binding threads may be formed from a material chosen from the group comprising polyamide, polyester, polyethylene, and polypropylene, or any other textile fiber.

[0071] Furthermore, the optical fibers can comprise a core formed from a material chosen from the group comprising polymethyl methacrylate (PMMA), polycarbonate (PC), and cyclo-olefins (COP). In this case, the optical fibers are made of two materials and have a core covered with a sheath which may be of different nature. The optical fibers may also be formed from a material chosen from the group comprising glass, quartz, and silica. In this case, a polymer sheath may cover the optical fibers to protect them. Also, these optical fibers either have a modification of the material of the optical cladding, or invasive alterations on their outer surface, so that the light propagating in the fiber escapes from the fiber through the modified cladding or these alterations. These alterations may be carried out in various ways, including by abrasion processes, chemical attack, or by laser treatment. In addition, these alterations may be distributed progressively over the surface of the optical fibers so as to ensure homogeneous lighting. The surface density or the dimension of the alterations can thus vary from one zone to another of the web. In general, close to the light source, the surface density of alterations is low, while it increases the further one moves away from the source.

[0072] The light source 7 intended to illuminate the free ends 6 of the optical fibers 2 may be of different types and is chosen from among those capable of generating radiation including UV-A ultraviolet radiation which is not very harmful. For example, the light source 7 may be in the form of light-emitting diodes, or even comprise a collector capable of focusing natural sunlight, which comprises about 4-5% UVA, in the direction of the free ends of the optical fibers.

[0073] In order to ensure antimicrobial action, the metal threads may be based on silver or copper metal threads. The metal threads can thus be pure silver threads or pure copper threads comprising for example 99.9% silver or copper, respectively. The metal threads may also be metal-coated textile threads. The diameter of the metal threads is unimportant and depends on the weaving technique or even on the desired flexibility of the textile web. By way of example, it is possible to use textile threads coated with silver having a titer of the order of 100 Dtex, or pure copper threads having a diameter on the order of 0.1 mm.

[0074] To increase the antimicrobial effect of the textile web, it is possible, according to another embodiment, to integrate photocatalytic particles having an effectiveness on the bacterial inactivation, such as titanium dioxide (TiO.sub.2).

[0075] For example, the photocatalytic particles may first be deposited on the optical fibers and/or the binding threads before weaving, in the form of a coating layer so as to form a sheath around each optical fiber and/or around each binding thread. The optical fibers and the metallic threads are then held together by weaving with the binding threads. To prevent premature aging of the optical fibers caused by the titanium dioxide, it is possible to provide for the deposition of a protective layer based on silica prior to the deposition of the photocatalytic layer. It is also possible to provide for the deposition of the photocatalytic layer after weaving the optical fibers and the metal threads with the binding threads. Thus, after weaving, a coating layer incorporating photocatalytic particles, as well as the intermediate layer of silica, is deposited.

[0076] Furthermore, depending on the application in which the textile web is intended to be implemented, it is possible to provide different configurations in the arrangement of the optical fibers and the metal threads.

[0077] It is in particular possible to envisage choosing to make the metallic threads and/or the optical fibers visible on the two opposite surfaces of the web or on only one of the two surfaces.

[0078] For example, the optical fibers 2 and the metallic threads 4 may be positioned so as to be visible on the two opposite surfaces 10, 11 of the textile web 1 (FIGS. 2A and 2B).

[0079] The weaving technique of the binding threads with the optical fibers and the metal threads is such that the textile web has on each of these two opposite surfaces 10, 11 an alternation of optical fibers and metallic threads. Different configurations of alternation between the optical fibers and the metallic threads may be envisaged on each of the surfaces of the textile web, such as those illustrated in FIGS. 2A and 2B. It is also possible to envisage an alternation between groups of optical fibers and groups of metal threads. In other words, each of the surfaces may comprise an alternation of optical groups and metal groups, each optical group being made up of one or more optical fibers and each metal group being made up of one or more metal threads.

[0080] The optical fibers 2 and the metal threads 4 can also be visible only on one and the same single surface 10 (FIG. 2C) of the textile web 1. In this case, the textile layer comprises only one luminous surface provided with metallic threads.

[0081] The optical fibers 2 and the metallic threads 4 can also be visible on opposite surfaces 10, 11 (FIG. 2D) of the textile web 1. Thus, the optical fibers are only visible on one side of the textile web and the metallic threads are only visible on the other side of the textile web.

[0082] Another variant consists in making the metallic threads 4 visible on the two surfaces 10, 11 of the web while the optical fibers 2 are only visible on one side of the textile web 1 (FIG. 2E), or else in making the fibers optical 2 visible on both sides 10, 11 and the metal thread 4 visible on one side of the textile web (FIG. 2F).

[0083] According to another variant, the textile web may be formed from a superposition of textile layers, each textile layer comprising optical fibers and metal threads which are held together by binding threads, and which are visible on one or both surfaces of the layer, for example according to at least one of the variants set out above. The textile web thus has more interstices (and therefore contact surfaces) to capture/trap the target microorganisms.

[0084] In another variant illustrated in FIG. 2G, a textile web based on optical fibers is superimposed onto another textile web based on metallic threads. The textile web can thus comprise a superposition of textile layers, a first textile layer 1b formed of optical fibers 2 held by binding threads and a second textile layer 1a being formed of metal threads 4 held by binding threads.

[0085] According to the same principle of the superposition of textile layers, it is possible to superimpose several textile webs, each of which may be according to any of the variants set out above.

[0086] The use of such a textile web formed of optical fibers and metal thread, in particular copper, provided or not with a photocatalytic layer is illustrated in FIG. 3. The textile web 1 is represented in a simplified manner. A light source 7 is positioned facing the free ends 6 of the optical fibers 2. These may be grouped together in bundles or not. Thus, the light emitted laterally by the optical fibers 2 may be transmitted on either side of the textile web 1 perpendicular to each of these surfaces, but also inside the textile web.

[0087] Surprisingly, it has been found that the combination of copper threads and UV-A radiation emitted by the optical fibers arranged near the copper threads makes it possible to significantly reduce or destroy the bacteria, in particular E. coli, contained in an aqueous medium. In addition, part of the copper ions released by the copper threads into the aqueous medium may be redeposited on the surface of the textile web, thus making it possible to maintain a copper stock for longer and therefore to ensure an antimicrobial effect over a longer period. duration. Thus, during the treatment process, the textile web may therefore have deposits of metal ions on the surface that were released by the metal threads during use.

[0088] As may be seen from the curves in FIG. 4, the result of the invention is not the simple combination of the effects of the metal copper or silver and UV. There is a real increase and a synergy of the antibacterial effect of the textile web provided with copper and/or silver threads combined with UV radiation and in particular with UV-A radiation.

[0089] The protocol for the tests making it possible to obtain the curves C1-C7 is as follows: a standardized bacterial suspension of E. coli in an aqueous medium is produced. 180 mL of this solution are placed in a reactor and temporal measurements of the concentration of E. coli in the medium are carried out in the following cases: [0090] curve C0: a textile web (dimensions 100*100 mm) made from fibers optics held by binding threads is immersed in the aqueous medium. The textile web is devoid of metallic threads and photocatalyst and is not connected to any light source. The aqueous medium is therefore not illuminated; [0091] curve C1: the textile web used for the curve C0 is now connected to a light source generating UV-A radiation with a wavelength on the order of 365 nm. The aqueous medium is therefore illuminated with UV-A radiation; [0092] curve C2: a textile web (dimensions 100*100 mm) according to any embodiment of the invention, incorporating metal threads but devoid of TiO.sub.2photocatalyst, is immersed in the aqueous medium. The textile web is not connected to any light source, and the assembly is placed in the dark so as to avoid any light radiation. Each metal thread is specially formed of a thread consisting of copper and silver twisted with polyester textile thread; [0093] curve C3: a textile web (dimensions 100*100 mm) according to any embodiment of the invention, incorporating metal threads also devoid of TiO.sub.2 layer, is immersed in the aqueous medium. The assembly is also placed in the dark so as to avoid any light radiation. The textile web is not connected to any light source, and the assembly is also placed in the dark so as to avoid any light radiation. Each metal thread is a pure copper monofilament with a diameter of 0.1 mm; [0094] curve C4: The textile web used for the curve C4 curve is similar to that used for the curve C2 except that each metal thread is obtained by assembling a polyamide thread impregnated with silver and a polyester. The textile web is immersed in the aqueous medium and the assembly is also placed in the dark so as to avoid any light radiation; [0095] curve C5: the textile web used to obtain curve C2 is now connected to a light source, an LED, generating UV-A radiation with a wavelength of about 365 nm; [0096] curve C6: the textile web used to obtain curve C3 is now connected to the light source generating UV-A radiation with a wavelength of about 365 nm; [0097] curve C7: the textile web used to obtain curve C4 is now connected to the light source generating UV-A radiation with a wavelength on the order of 365 nm.

[0098] The medium is in recirculation. Measurements are taken every hour for 8 hours. In particular, the quantity of viable cultivable bacteria remaining in the medium is determined by counting the bacteria on a rich medium.

[0099] There is a real increase and a synergy of the antibacterial effect of the textile web provided with lateral emission optical fibers woven with silver and/or copper metallic threads (curves C5, C6 and C7) combined with UV radiation and in particular with UV-A radiation. The result of the invention is therefore not the simple combination of the effects of copper or silver metal and UV.

[0100] FIG. 5 also shows the notorious effect of the textile web of the invention based on copper threads and optical fibers diffusing UV-A radiation. The test protocol is identical to that described above. A standardized bacterial suspension of E. coli in an aqueous medium is made. 180 mL of this solution is placed in a reactor and time measurements of the concentration of E. coli in the medium are performed in the following cases: [0101] curve C8: a textile web (dimensions 100*100 mm) based on optical fibers held by binding threads is immersed in the aqueous medium. The textile web is devoid of metal threads and of the TiO.sub.2 particle and is connected to a light source generating UV-A radiation with a wavelength of about 365 nm; [0102] curve C9: a textile web (dimensions 100*100 mm) according to any embodiment of the invention incorporating pure copper threads and devoid of a TiO.sub.2layer, is immersed in the aqueous medium. The textile web is not connected to a light source and the assembly is placed in the dark so as to avoid any light radiation; [0103] curve C10: the web used to obtain curve C9 is this time connected to a light source generating UV-A radiation with a wavelength of about 365 nm; [0104] curve C11: a textile web (dimensions 100*100 mm) according to any embodiment of the invention integrating TiO.sub.2 particles and pure copper threads, is immersed in the aqueous medium and is connected to the light source generating UV-A radiation with a wavelength of about 365 nm.

[0105] There is also an additional advantage of the antibacterial effect of the textile web coated with photocatalyst (TiO.sub.2) according to the invention combined with UV-A radiation (curve C11) compared to a textile web of the invention without TiO.sub.2 (Curve C10).

[0106] In a gaseous medium, for example in the surrounding air, the bacteria may be temporarily suspended in the air and the protocol used therefore aims to mimic this type of aerial bacterial contamination. An aerosol of a standardized E. coli bacterial solution is generated for 5 hours in continuous flow through a sealed device (chamber) containing the textile web of the invention integrating copper threads and a photocatalyst. At the outlet of the sealed device, the air flow containing the bacterial aerosol bubbles through a bottle containing an aqueous solution, making it possible to collect the bacteria still suspended in the air. Thus, curve C12 represents the quantity of viable cultivable bacteria present initially, determined by counting the bacteria on rich medium and curve C13 represents the quantity of bacteria counted at the end of the test after 5 hours under UV-A irradiation via the textile web of the invention. Under these experimental conditions, significant bacterial inactivation is observed when UV-A activates the TiO.sub.2 compared to the results obtained with the control conditions.

[0107] This invention thus finds various applications such as the treatment of air in hospitals, of liquids, or of surfaces. The very structure of the textile web allows in particular easy installation in places where the supply of light radiation is not always easy, for example in a shoe for a disinfection phase via the connection of the textile web. to an LED generating UV radiation.

[0108] The treatment solution of the invention is essentially described in relation to the E. Coli bacterium, but it can also be implemented for the inactivation or elimination of other microorganisms such as those identified for copper and silver.