PERSONAL PROTECTION EQUIPMENT FOR PROTECTING A USER FROM AIRBORNE PATHOGENS

Abstract

A disposable mask or optically transparent mask comprising a mask body is provided. The disposable mask includes a periphery, and straps attached to the mask body proximate the periphery for releasably retaining the mask on a user's face, the mask body including: an inner layer, which is a polymeric plastic material with a plurality of passageways therethrough, and which has an inner surface and an outer surface; and a porous glass filter which is functionalized with a visible light photocatalyst and abuts the outer surface of the inner layer. Apparel comprising fiberglass which is functionalized with a visible light photocatalyst is also provided.

Claims

1. A disposable mask comprising a mask body, which includes a periphery, and straps attached to the mask body proximate the periphery for releasably retaining the mask on a user's face, the mask body including: an inner layer, which is a polymeric plastic material with a plurality of passageways therethrough, and which has an inner surface and an outer surface; and a porous glass filter which is functionalized with a visible light photocatalyst and abuts the outer surface of the inner layer.

2. The disposable mask of claim 1, wherein the visible light photocatalyst is a low iron oxide, iron-doped titanium dioxide nanoparticle.

3. The disposable mask of claim 2, wherein the porous glass filter is in a filter zone bounded by a boundary zone, the boundary zone comprising the inner layer and extending from the filter zone to the periphery.

4. The disposable mask of claim 2 or 3, wherein the porous glass filter is a fiberglass fabric.

5. The disposable mask of any one of claims 2 to 4, wherein the low iron oxide, iron-doped titanium dioxide nanoparticles have substantially iron oxide free surfaces.

6. The disposable mask of any one of claims 2 to 5, the mask body further comprising a formable border proximate the periphery of the inner surface of the inner layer.

7. The disposable mask of any one of claims 2 to 6, the mask body further comprising a transparent outer cover which is a polymeric plastic material with a plurality of passageways therethrough and abuts the fiberglass filter.

8. The disposable mask of any one of claims 2 to 7, the mask body further comprising a filter layer, the filter layer abutting the outer surface of the inner layer.

9. The disposable mask of claim 8, wherein the filter layer consists of unbonded plastic polymer fibers.

10. A method of reducing pathogens in air inhaled and exhaled by a user, the method comprising providing a disposable mask which a mask body, which includes a periphery, and straps attached to the mask body proximate the periphery for releasably retaining the mask on a user's face, the mask body including: an inner layer, which is a polymeric plastic material with a plurality of passageways therethrough, and which has an inner surface and an outer surface; and a porous glass filter which is functionalized with a visible light photocatalyst and abuts the outer surface of the inner layer; the user putting the disposable mask on their face; and the user breathing through the disposable mask.

11. The method of claim 10, wherein the mask body reduces mean tidal volume by no more than about 16.2%.

12. A face mask comprising an optically transparent or optically semi-transparent mask body, a periphery about an edge of the optically transparent or optically semi-transparent mask body and straps attached to the mask body proximate to the periphery or attached to the periphery for releasably retaining the mask on a user's face, the mask body including: an inner layer, which is an optically transparent or optically semi-transparent material with a plurality of passageways therethrough, and which has an inner surface and an outer surface; and a fiberglass fabric layer which abuts the outer surface of the inner layer and which comprises fiberglass ribbons.

13. The face mask of claim 12, wherein the fiberglass fabric is functionalized with a visible light photocatalyst.

14. The face mask of claim 13, wherein a refractive index of the optically transparent or optically semi-transparent material of the inner layer and a refractive index of the fiberglass ribbons of the fiberglass fabric layer are within about 0.06 of one another.

15. The face mask of claim 13 or 14, wherein the visible light photocatalyst is low iron oxide, iron-doped titanium dioxide.

16. The face mask of claim 15, wherein the low iron oxide, iron-doped titanium dioxide is nanoparticles.

17. The face mask of claim 16, wherein the low iron oxide, iron-doped titanium dioxide nanoparticles have substantially iron oxide free surfaces.

18. The face mask of any one of claims 12 to 17, the mask body further comprising a formable border proximate to the periphery.

19. The face mask of any one of claims 15 to 18, the mask body further comprising an outer cover which is an optically transparent or optically semi-transparent material with a plurality of passageways therethrough and which abuts the fiberglass fabric layer.

20. The face mask of claim 19, wherein a refractive index of the optically transparent or optically semi-transparent material of outer cover, the refractive index of the optically transparent or optically semi-transparent material of the inner layer and the refractive index of the fiberglass ribbons of the fiberglass fabric layer are within about 0.060.

21. The face mask of any one of claims 15 to 20, the mask body further comprising an optically transparent or optically semi-transparent filter layer, the filter layer between the outer surface of the inner layer and the fiberglass fabric layer.

22. The face mask of claim 21, wherein the optically transparent or optically semi-transparent filter layer consists of unbonded plastic polymer fibers.

23. The face mask of claim 22, wherein a refractive index of the unbonded plastic polymer fibers, the refractive index of the optically transparent or optically semi-transparent material of the outer cover, the refractive index of the optically transparent or optically semi-transparent material of the inner layer and the refractive index of the fiberglass ribbons of the fiberglass fabric layer are within about 0.060.

24. The face mask of any one of claims 15 to 23, wherein the inner layer comprises a silk fibroin or a rayon material.

25. The face mask of claim 24, wherein the inner layer is a silk fibroin material.

26. The face mask of any one of claims 15 to 25, wherein the outer layer comprises a silk fibroin or rayon material.

27. The face mask of claim 26, wherein the outer layer is a silk fibroin material.

28. The face mask of any one of claims 12 to 27 wherein the mask body is optically transparent.

29. The face mask of any one of claims 12 to 28, wherein the fiberglass fabric layer consists of fiberglass ribbons functionalized with low iron oxide, iron-doped titanium dioxide nanoparticles that have substantially iron oxide free surfaces.

30. A method of manufacturing an optically semi-transparent or optically transparent mask body for a face mask, the method comprising: selecting a fiberglass material consisting of fiberglass ribbons functionalized with low iron oxide, iron-doped titanium dioxide nanoparticles; shaping the fiberglass material into a mask body shape; selecting an inner layer consisting of an optically transparent or optically semi-transparent material with a refractive index within 0.06 of a refractive index of the fiberglass material; shaping the optically transparent of optically semi-transparent material into the mask body shape; and attaching the inner layer to the fiberglass material, thereby manufacturing an optically semi-transparent or transparent mask body.

31. The method of claim 30, further comprising selecting an outer layer consisting of an optically transparent or optically semi-transparent material with a refractive index within 0.06 of the refractive index of the fiberglass material and the inner layer; and attaching the outer layer to the fiberglass material, thereby manufacturing an optically semi-transparent or transparent mask body.

32. An article of personal protection apparel, the article comprising a fiberglass fabric functionalized with a visible light photocatalyst.

33. The article of claim 32, wherein the visible light photocatalyst is a low iron oxide, iron-doped titanium dioxide nanoparticle.

34. The article of claim 33, wherein the low iron oxide, iron-doped titanium dioxide nanoparticles have substantially iron oxide free surfaces.

35. The article of any one of claims 32 to 34, wherein the article is selected from the group consisting of a cap, a gown, a hooded gown, a pair of booties and a pair of pants.

36. A face shield, the face shield comprising a band and a transparent visor which is attached to the band, the transparent visor functionalized with a visible light photocatalyst.

37. The face shield of claim 36, wherein the visible light photocatalyst is a low iron oxide, iron-doped titanium dioxide nanoparticle.

38. The face shield of claim 37, wherein the low iron oxide, iron-doped titanium dioxide nanoparticles have substantially iron oxide free surfaces.

Description

FIGURES

[0065] FIG. 1 is a perspective view of the disposable mask of the present technology.

[0066] FIG. 2 is a sectional view through lines A-A of FIG. 1.

[0067] FIG. 3 is a sectional view of an alternative embodiment through lines A-A of FIG. 1.

[0068] FIG. 4 is an inside view of the disposable mask of FIG. 1.

[0069] FIG. 5 is a sectional view of an alternative embodiment of FIG. 1.

[0070] FIG. 6 is a schematic showing gaseous exchange between the user and an ambient environment.

[0071] FIG. 7 is a schematic of fiberglass fabric or fiberglass ribbons functionalized with low iron oxide, iron-doped titanium dioxide nanoparticles.

[0072] FIG. 8A is an inside view of an alternative embodiment disposable mask; FIG. 8B is a sectional view of the disposable mask along line 8B-8B.

[0073] FIG. 9 is a block diagram showing the manufacturing of the fiberglass ribbons and the resultant fabric.

[0074] FIG. 10 is a block diagram showing an alternative method of manufacturing the fiberglass ribbons and the resultant fabric.

[0075] FIG. 11 is a schematic of functionalized fiberglass fabric apparel.

[0076] FIG. 12 is a schematic of a face shield.

DESCRIPTION

[0077] Except as otherwise expressly provided, the following rules of interpretation apply to this specification (written description and claims): (a) all words used herein shall be construed to be of such gender or number (singular or plural) as the circumstances require; (b) the singular terms “a”, “an”, and “the”, as used in the specification and the appended claims include plural references unless the context clearly dictates otherwise; (c) the antecedent term “about” applied to a recited range or value denotes an approximation within the deviation in the range or value known or expected in the art from the measurements method; (d) the words “herein”, “hereby”, “hereof”, “hereto”, “hereinbefore”, and “hereinafter”, and words of similar import, refer to this specification in its entirety and not to any particular paragraph, claim or other subdivision, unless otherwise specified; (e) descriptive headings are for convenience only and shall not control or affect the meaning or construction of any part of the specification; and (f) “or” and “any” are not exclusive and “include” and “including” are not limiting. Further, the terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted.

[0078] Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. Where a specific range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range, is included therein. All smaller sub ranges are also included. The upper and lower limits of these smaller ranges are also included therein, subject to any specifically excluded limit in the stated range.

[0079] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the relevant art. Although any methods and materials similar or equivalent to those described herein can also be used, the acceptable methods and materials are now described.

Definitions

[0080] Pathogen—in the context of the present technology, a pathogen is a living microbe that causes disease. Pathogens include but are not limited to a bacterium, a fungus or a virus.

[0081] Aerosol—in the context of the present technology an aerosol is a suspension of solid and/liquid particles in a gas.

[0082] Fiberglass fabric—in the context of the present technology, fiberglass fabric is comprised of glass threads in a plain weave. It may have any thread count, for example, but not limited to 20×14 to 60×52, to 70×70 and may have a thickness, of, for example, but not limited to 2.5 microns to 250 microns. The thread count and the thickness of the threads determines the porosity of the end product.

[0083] Iron-doped titanium dioxide with a low iron oxide surface—in the context of the present technology, iron-doped titanium dioxide with a low iron oxide surface has about 0.1 atomic % iron to about 2.0 atomic % iron, preferably 0.25 atomic % iron to about 0.75 atomic % iron, and more preferably 0.5 atomic % iron and very small amounts of iron oxide on its surface (less than 5% of the surface being iron oxide) when viewed with X-ray photoelectron spectroscopy.

[0084] Fiberglass ribbons—in the context of the present technology, a fiberglass ribbon is a length of fiber that has been flattened.

[0085] Flattened fiber, fiberglass fabric—in the context of the present technology, fiberglass fabric is comprised of glass threads in a plain weave. It may have any thread count, for example, but not limited to 20×14 to 60×52, to 70×70 and may have a thickness, of, for example, but not limited to 2.5 microns to 250 microns. The thread count and the thickness of the threads determines the porosity of the end product. The glass threads, also known as fibers, are all flattened into ribbons on the same plane and that plane is parallel to the upper and the lower surface of the face mask.

[0086] Optically transparent—in the context of the present technology, optically transparent means that images can be seen through the material.

[0087] Substantially iron oxide free surface—in the context of the present technology, a substantially iron oxide free surface has an iron oxide content corresponding to less than about 0.001% atomic iron (less than 0.5% of the surface being iron oxide) when viewed with X-ray photoelectron spectroscopy.

[0088] Fluid—in the context of the present technology, a fluid is a gas, a liquid or both.

[0089] Airborne—in the context of the present technology, airborne includes aerosols and particles in the air.

[0090] Porous glass filter layer—in the context of the present technology, a porous glass filter layer is a layer of fiberglass fabric or a layer of sintered glass.

DETAILED DESCRIPTION

[0091] A disposable mask, generally referred to as 10 is shown in FIG. 1. The mask has a mask body 12, a nose piece 14 and two straps 16. The nose piece 14 is formable and is preferably aluminum or a pliable plastic, which when molded on a user's nose retains its shape. The straps 16 are preferably elastomeric and are retained on the mask body 12. The mask body 12 is sufficiently resilient to maintain its shape when in use. It may be, as shown, cup-shaped.

[0092] As shown in FIG. 2, the mask body 12 is lamellar with an outer cover 20, a fiberglass filter layer 22 and an inner layer 24. The outer cover 20 is preferably a polyester or other plastic polymer and is transparent to visible light. The polyester or other plastic polymer is made of fibers which are either bonded to one another or are woven, in order to provide passageways. The fiberglass filter layer 22 is woven. It is functionalized with low iron oxide, iron-doped titanium dioxide nanoparticles. The inner layer 24 is a polyester or other woven plastic polymer. The polyester or other plastic polymer is made of fibers which are either bonded to one another or are woven, in order to provide passageways. Nose foam 26 is attached to the inner layer 24 under the nose piece 14.

[0093] In an alternative embodiment, the outer cover 12 is a silk fibroin material. It may be woven or printed, such as three dimensionally printed or lithographically printed to provide a suitable pore size.

[0094] In another embodiment, shown in FIG. 3, the mask body is lamellar with an outer cover 20, a fiberglass filter layer 22, a filter layer 30 and the inner layer 24. The outer cover 20 is preferably a polyester or other plastic polymer and is transparent to visible light. In one embodiment it is optically transparent. The polyester or other plastic polymer is made of fibers which are either bonded to one another or are woven, in order to provide passageways. The fiberglass filter layer 22 is woven. In one embodiment it is optically transparent. It is functionalized with low iron oxide, iron-doped titanium dioxide nanoparticles. The filter layer 30 is preferably made of plastic polymer fibers which are not bonded and not woven and provide passageways. The inner layer 24 is a polyester or other woven plastic polymer. In one embodiment it is optically transparent. The polyester or other plastic polymer is made of fibers which are bonded to one another or are woven, in order to provide passageways. Nose foam 26 is attached to the inner layer 24 under the nose piece 14.

[0095] In another embodiment, shown in FIGS. 4, the periphery of the mask body 12, generally referred to as 40, is provided with a formable border 42. The formable border 42 is pliable and can be molded to a user's face. The formable border 42 is preferably a thin layer of foam or silicone rubber (about 1 mm to about 3 mm). The formable border 42 reduces the chance of air flow between the disposable mask 10 and the user's face.

[0096] In another embodiment, shown in FIG. 5, the mask body 12 is lamellar with a fiberglass filter layer 22 and an inner layer 24. The fiberglass filter layer 22 is woven and is optically transparent. It is functionalized with low iron oxide, iron-doped titanium dioxide nanoparticles. The inner layer 24 is a plastic polymer material or rayon material and is optically transparent. The plastic polymer material or rayon material is made of fibers which are either bonded to one another or are woven, in order to provide passageways. Nose foam 26 is attached to the inner layer 24 under the nose piece 14.

[0097] Using the embodiment of FIG. 3 as an example, the flow of gases into and out of the disposable mask or transparent mask is shown in FIG. 6. The passageways of the outer cover 20 and the inner layer 24 are large enough to have a minimal impact on gas exchange. Accordingly, the passageways are in the range of about 0.3 microns to about 0.9 microns, preferably about 0.6 microns to about 0.9 microns. When present, the inner filter layer 30 has passageways of about 0.3 microns to about 0.9 microns, preferably about 0.6 microns to about 0.9 microns.

[0098] As shown in FIG. 7, the fiberglass filter layer 22 has interstitial spaces 50 between the woven fibers 52. Nanoparticles 54 are attached to the woven fibers 52. Although the weave shown is a one over one weave, other weaves are contemplated. The interstitial spaces 50 are about 0.5 microns to about 1.0 microns across, preferably about 0.9 microns.

[0099] In one embodiment, the fiberglass fibers are flattened into ribbons 52 along a single plane which is parallel to the outer cover 20, if present, the inner layer 24 and the filter layer 30, if present. The plastic polymer, rayon or silk fibroin in each layer is matched to the refractive index of the fiberglass ribbons, thus maximizing optical clarity. If different materials including a plastic polymer, rayon or silk fibroin are used in the layers, they are matched to the refractive index of both the fiberglass ribbons 50 and the other layer or layers. Specifically, the refractive index of the plastic polymer is within about 0.010 of the refractive index of the fiberglass ribbons at wavelengths between about 380 nm and about 700 nm.

[0100] Potential plastic polymers that provide transparency when used with the fiberglass fabric and their refractive indices are as follows.

TABLE-US-00001 TABLE 1 Poly(2-chloroethyl methacrylate) 1.503 Poly(cyclohexyl methacrylate) 1.507 Poly(isobutene) 1.507 Poly(2-hydroxyethyl methacrylate) 1.507 Poly(tetrahydrofurfuryl methacrylate) 1.508 Poly(acrylic acid), PAA 1.508 Poly(acrylonitrile) 1.513 Poly(methyl isopropenyl ketone) 1.520 Polyisoprene 1.521 Poly(w-dodecanamide), Nylon 12 1.525 Poly(vinyl alcohol) 1.526 Poly(N-methyl-methacrylamide) 1.529 Poly(N-methyl-methacrylamide) 1.529 Poly(caprolactam), ylon 6 1.530 Poly(hexamethylene adipamide), Nylon 6,6 1.530 Poly(vinyl chloride), PVC 1.531 Poly(2-bromoethyl methacrylate) 1.535 Poly(hexamethylene sebacamide), Nylon 6,10 1.539

[0101] Other potential materials, such as, but not limited to, are silk fibroin with a refractive index of 1.54 or rayon with a refractive index of 1.54-1.55.

[0102] In an alternative embodiment, the refractive index of the plastic polymeric materials is within 0.1, preferably within 0.06 and most preferably within 0.03 of that of borosilicate glass and the mask body 12 is optically semi-transparent.

TABLE-US-00002 TABLE 2 Poly(2,2,3,3-tetrafluoropropyl methacrylate) 1.420 Poly(vinylidene fluoride), PVDF 1.426 Poly(isobutyl vinyl ether) 1.451 Poly(oxymethylene) 1.453 Poly(ethylene glycol) 1.458 Poly(methyl vinyl ether) 1.458 Poly(pentyl vinyl ether) 1.459 Poly(vinyl methyl ketone) 1.459 Poly(hexyl vinyl ether) 1.459 Poly(octyl vinyl ether) 1.461 Poly(3-ethoxypropyl acrylate) 1.462 Poly(4-methyl-1-pentene) 1.462 Poly(isopropyl methacrylate) 1.463 Poly(ethyl vinyl ether) 1.463 Poly(tert-butyl methacrylate) 1.464 Poly(dodecyl methacrylate) 1.465 Poly(butyl acrylate), PBA 1.465 Polylactic acid, PLA 1.465 Poly(ethyl acrylate), PEA 1.467 Poly(2-ethoxyethyl acrylate) 1.474 Poly(methyl acrylate), PMA 1.476 Poly(ethylene) 1.476 Poly(vinyl formate) 1.476 Poly(isobutyl methacrylate) 1.480 Poly(hexyl methacrylate) 1.481 Poly(3-methoxypropyl acrylate) 1.483 Poly(butyl methacrylate) 1.483 Poly(propyl methacrylate) 1.484 Poly(vinyl acetate) 1.484 Poly(vinyl butyral) 1.485 Poly(methyl methacrylate) 1.491 Poly(2-ethoxyethyl methacrylate) 1.495 Poly(1-butene) 1.497 Poly(ethyl methacrylate) 1.498 Poly(2-chloroethyl methacrylate) 1.503 Poly(cyclohexyl methacrylate) 1.507 Poly(isobutene) 1.507 Poly(2-hydroxyethyl methacrylate) 1.507 Poly(tetrahydrofurfuryl methacrylate) 1.508 Poly(acrylic acid), PAA 1.508 Poly(acrylonitrile) 1.513 Poly(methyl isopropenyl ketone) 1.520 Polyisoprene 1.521 Poly(w-dodecanamide), Nylon 12 1.525 Poly(vinyl alcohol) 1.526 Poly(N-methyl-methacrylamide) 1.529 Poly(N-methyl-methacrylamide) 1.529 Poly(caprolactam), nylon 6 1.530 Poly(hexamethylene adipamide), Nylon 6,6 1.530 Poly(vinyl chloride), PVC 1.531 Poly(2-bromoethyl methacrylate) 1.535 Poly(hexamethylene sebacamide), Nylon 6,10 1.539 Poly(1,4-butadiene) 1.539 Poly(2-phenylethyl methacrylate) 1.547

[0103] As shown in FIG. 8A, in an alternative embodiment, the mask body 12 has a sintered glass zone 100 which is bounded by a boundary zone 102. The boundary zone 102 is flexible and allows the mask body 12 to form-fit a user's face, covering their mouth, chin and nose. The mask body 12 may or may not include the formable border 42. As shown in FIG. 8B, the sintered glass zone 100 includes at least a functionalized sintered glass filter layer 104 and the inner layer 24. The outer cover 20 is optional and if present, is light transparent. The boundary zone 102 includes at least the outer cover 20 and the inner layer 24 and may include the filter layer 30. The functionalized thin sintered glass filter layer 104 is about 2 microns to about 20 microns thick. The thickness dictates the flexibility, thus a minimal thickness is desired. Flexibility in the functionalized thin sintered glass layer 104 is sufficient to permit bending to an effective radius of curvature of less than 20 centimeters, preferably less than 5 centimeters, more preferably less than 1 centimeter, and most preferably less than 0.5 centimeter or some equivalent measure. The thin sintered glass is functionalized after sintering.

[0104] In another embodiment, the sintered glass zone is replaced with a fiberglass zone, rather than the fiberglass filter layer having the same dimensions as the mask body 12. The fiberglass zone has functionalized fiberglass sandwiched between at least the outer cover and the inner layer.

[0105] In another alternative embodiment, the outer cover is not present and the outermost layer is the fiberglass filter layer.

[0106] In yet another alternative embodiment, the outermost layer is the fiberglass filter layer. A standard disposable mask is attached to the inner surface of the fiberglass filter layer. This embodiment does not address poor gas exchange of a standard mask.

[0107] In all embodiments, the fiberglass filter layer is separated from the user's face with at least the inner layer. This layer traps any nanoparticles or fiberglass fibers that might break away from the fiberglass filter layer.

[0108] One method of preparing the optically transparent fiberglass fabric is shown in FIG. 9. A boule of borosilicate glass is heated 100 to about 1200 C. Glass fibers are pulled 102 into a viscous liquid thread. As the pulled viscous liquid thread is cooling 104 it is passed 106 through hot rollers, flattening 108 the fibers into ribbons. The fiberglass ribbon is then woven 110 together with other flattened ribbons to make the optically transparent fiberglass fabric. The optically transparent fiberglass fabric is then wound 112 around a post to make a bolt of fabric.

[0109] A second method of preparing the optically transparent fiberglass fabric is shown in FIG. 10. Pre-made fiberglass fabric is heated 120 to about 1100 C, such that it the fibers are an amorphous solid. The fiberglass fiber is passed 122 through hot rollers, flattening 124 the fibers in the fabric into ribbons. The optically transparent fiberglass fabric is then wound 126 around a post to make a bolt of fabric.

[0110] The functionalized fiberglass fabric, the functionalized optically transparent fiberglass fabric or the functionalized sintered glass are functionalized with low iron oxide, or substantially iron oxide free, iron-doped titanium dioxide which preferably contains about 0.5 atomic % iron but can range from about 0.1 atomic % iron to about 2.0 atomic % iron.

[0111] In another embodiment the functionalized fiberglass fabric is between about 50 microns to about 1 mm thick and preferably 60 microns thick and is used in personal protection apparel. As shown in FIG. 11, the apparel includes a cap 200, a gown 202, booties 204, a hooded gown 206 and pants 208.

[0112] The functionalized fiberglass fabric or the functionalized sintered glass are functionalized with low iron oxide, or substantially iron oxide free, iron-doped titanium dioxide which preferably contains about 0.5 atomic % iron but can range from about 0.1 atomic % iron to about 2.0 atomic % iron.

[0113] As shown in FIG. 12, a glass or plastic face shield, generally referred to as 210 includes a band 212 and a visor 214. The visor 214 is functionalized with low iron oxide, or substantially iron oxide free, iron-doped titanium dioxide which preferably contains about 0.5 atomic % iron but can range from about 0.1 atomic % iron to about 2.0 atomic % iron.

[0114] Plastic or glass goggles have lenses that are functionalized with low iron oxide, or substantially iron oxide free, iron-doped titanium dioxide which preferably contains about 0.5 atomic % iron but can range from about 0.1 atomic % iron to about 2.0 atomic % iron.

[0115] One method of preparing the low iron oxide, iron-doped titanium dioxide functionalized fiberglass, functionalized optically transparent fiberglass fabric or sintered glass is as follows:

[0116] The iron-doped titanium dioxide nanoparticles were prepared by the sol-gel method using titanium isopropoxide (TTIP) as the precursor and ferric nitrate (Fe(NO3)3.9H2O) as the iron source. Firstly, the desired amount of ferric nitrate (0.25, 0.5, 1, 5 and 10 molar %) was dissolved in water and then the solution was added to 30 mL of anhydrous ethyl alcohol and stirred for 10 minutes. The acidity of the solution was adjusted to about pH 3 (about pH 2.5 to about pH 3.5) using HNO3 (other acids could also be used), which produces better Fe doped TiO2, i.e., incorporation of Fe into the TiO2 nanocrystals. Secondly, TTIP was added dropwise to the solution. Then deionized water with the ratio of Ti:H2O (1:4) was added to the mixture. The solution was stirred for two hours, poured onto the fiberglass fabric and then dried at 80° C. to form particles on the fiberglass fabric. The combination of the particles and the fiberglass fabric was then washed three times with deionized water. Next, the combination was calcined at 400° C. for four hours to adhere the iron-doped titanium dioxide nanoparticles to the fiberglass fibers of the fabric, thus producing functionalized fiberglass. The functionalized fiberglass was washed in an HCl solution (acid washed) and then washed with deionized water three times. The acid washing was in a solution of about pH 2.5 to about pH 3.5, or about pH 4, with, preferably, a monoprotic acid, such as, for example, but not limited to acetic acid (CH3CO2H or HOAc), hydrochloric acid (HCl), hydroiodic acid (HI), hydrobromic acid (HBr), perchloric acid (HClO4), nitric acid (HNO3) or sulfuric acid (H2SO4), with HCl being the preferred. Through analysis, it was shown that the nanoparticles bind to the fiberglass fibers or the sintered glass. The binding between the glass and Fe doped TiO.sub.2 is between the oxygen ions and not between Si and Ti ions.

[0117] A second method of preparing the low iron oxide, iron-doped titanium dioxide functionalized fiberglass, functionalized optically transparent fiberglass fabric or sintered glass is as follows:

[0118] The low iron oxide, iron-doped titanium dioxide nanoparticles were prepared by the sol-gel method using titanium isopropoxide (TTIP) as the precursor and ferric nitrate (Fe(NO.sub.3)3.9H.sub.2O) as the iron source. Firstly, the desired amount of ferric nitrate (0.25, 0.5, 1, 5 and 10 molar %) was dissolved in water and then the solution was added to 30 mL of anhydrous ethyl alcohol and stirred for 10 minutes. The acidity of the solution was adjusted to about pH 3 (about pH 2.5 to about pH 3.5) using HNO.sub.3 (other acids could also be used), which produces better Fe doped TiO.sub.2, i.e., incorporation of Fe into the TiO.sub.2 nanocrystals. Secondly, TTIP was added dropwise to the solution. Then deionized water with the ratio of Ti:H.sub.2O (1:4) was added to the mixture. The solution was stirred for two hours and then dried at 80° C. for two hours.

[0119] The powders were then washed three times with deionized water. Next, the powder was calcined at 400° C. for three hours. The calcined powder was stirred in an HCl solution (acid washed) and then washed with deionized water three times. The acid washing was in a solution of about pH 2.5 to about pH 3.5, or about pH 4, with, preferably, a monoprotic acid, such as, for example, but not limited to acetic acid (CH.sub.3CO.sub.2H or HOAc), hydrochloric acid (HCl), hydroiodic acid (HI), hydrobromic acid (HBr), perchloric acid (HClO.sub.4), nitric acid (HNO.sub.3) or sulfuric acid (H.sub.2SO.sub.4), with HCl being the preferred. The acid washing produced low iron oxide, iron-doped titanium dioxide. The low iron oxide, iron-doped titanium dioxide nanoparticles were suspended in water and either sprayed onto the fiberglass fabric or sintered glass, or the fiberglass fabric or sintered glass was immersed in the water. The combination of the fiberglass fabric and the low iron oxide, iron-doped titanium dioxide nanoparticles was calcined at 400° C. for four hours to adhere the low iron oxide, iron-doped titanium dioxide nanoparticles to the fiberglass fibers of the fabric, thus producing functionalized fiberglass. Through analysis, it was shown that the nanoparticles bind to the fiberglass fibers or ribbons. The binding between the glass and Fe doped TiO.sub.2 is between the oxygen ions and not between Si and Ti ions.

[0120] A third method of preparing the optically transparent, low iron oxide, iron-doped titanium dioxide functionalized fiberglass is as follows: High purity iron of 99.999% (made by electrolytic refining) and titanium dioxide of 99.999% purity are mixed together as epi-layers on the fiberglass fabric using sputter deposition methods. Argon, nitrogen or xenon of 99.999% purity are used as the ionized gas. A thin epi layer of titanium dioxide is deposited followed by an epi layer of iron and a second epi layer of titanium dioxide. One method employed, which has some control over the amount of the deposition, involved depositing 100 nm titanium dioxide, then depositing 10 nm iron followed by depositing another 100 nm layer of titanium dioxide for an epi-layer thickness of 210 nm. This was then annealed to homogenize the iron within the titanium dioxide producing a material of 4.7 vol % iron doped titanium dioxide or 8.7 wt % iron doped titanium dioxide. Adjusting the thickness of the deposited iron epi-layer sandwiched between the titanium epi-layers allows for the synthesis of a range of concentrations of iron doping. This method does not require acid washing.

[0121] In an alternative embodiment, a face mask 10 with an optically semi-transparent or optically transparent mask body 12 is provided that includes a fiberglass fabric layer consisting of fiberglass ribbons. The fiberglass ribbons and the fiberglass fabric is not functionalized.

[0122] The mask body 12 is manufactured by selecting the appropriate materials for the inner layer and the outer layer in terms of optical transmission and then checking that the refractive indices are close enough to the refractive index of the fiberglass material. Once selected, the materials are shaped (cutting and potentially forming) to the shape of the mask body 12. Either before shaping or after shaping the layers are attached to one another to provide the mask body.

[0123] Regardless of the method of producing the low iron oxide, iron-doped titanium dioxide nanoparticle functionalized fiberglass fabric, the acid washing was shown to remove a significant amount of iron oxide from the surface of the nanoparticles. The acid-washed iron-doped titanium dioxide nanoparticles function as catalysts under visible light.

[0124] The method of reducing or eliminating airborne pathogens is as follows:

[0125] A user places the disposable mask or optically transparent mask of any of the embodiment described above over their mouth, nose and chin, places the elastomeric straps around their ears or around their head and crimps the nose piece so that it conforms to the shape of the user's nose. The user checks to ensure that there are no gaps between the user and the mask. The mask covers part of the nose, including the nostrils, part of the cheeks, and part of the chin, if fitted correctly. The user breaths normally. As the air being expelled from the user is moist, and the functionalized fiberglass layer is exposed to visible light, the nanoparticles act as photocatalysts. Without being bound to theory, the low iron oxide iron doped titanium dioxide produces electrons and holes when exposed to visible light. The electrons combine with Fe+3 in the low iron oxide iron doped titanium dioxide to form Fe+2 and the hole combines with Fe+3 to form Fe+4. The Fe+2 ion reacts with O2 from the air to form superoxide, an oxidizing radical. The Fe+4 ion reacts with OH— ions from water in the air to form the hydroxyl radical. Thus, the moist air that is expelled from the user initiates this reaction in the presence of visible light. The radicals then inhibit growth or eliminate the pathogens. During inhalation, moisture that it retained in the mask allows for the reaction to occur, even in the absence of sufficient moisture in the air. The moisture is retained by the inner layer, which is adjacent to the functionalized fiberglass layer, allowing moisture to wick into the functionalized fiberglass layer.

Example 1

[0126] The mask of FIG. 2, which has only one filtration layer, reduced mean tidal volume by an average of 13.7% in a sample of five users and lowered minute ventilation by an average of 15.2% in a sample of five user.

Example 2

[0127] The mask of FIG. 3, which has two filtration layers reduced mean tidal volume by an average of 16.2% in a sample of five users and lowered minute ventilation by an average of 18.4% in a sample of five users.

Example 3

[0128] The low iron oxide, iron-doped titanium dioxide functionalized fiberglass or functionalized optically transparent fiberglass fabric will be tested for its virucidal activity. Surrogate coronaviruses, mouse hepatitis virus (MHV) and transmissible gastroenteritis virus, were used in the AATCC 100 test, modified for viruses, as follows:

[0129] Low iron oxide, iron-doped titanium dioxide functionalized fiberglass or functionalized optically transparent fiberglass fabric and control (not functionalized) fiberglass fabrics are cut to swatches of the appropriate size for the study.

[0130] A 1.0 ml inoculum volume is applied to the low iron oxide, iron-doped titanium dioxide functionalized fiberglass and control swatches, taking care to ensure that the suspension touches only the fabric. The inoculum must be fully absorbed-more swatches can be added if necessary.

[0131] A 1.0 ml inoculum volume is also applied to a separate set of untreated cotton swatches to serve as the “Time Zero” control.

[0132] The “Time Zero” control is immediately neutralized in the appropriate media. The suspension is serially diluted and each dilution is plated in quadruplicate to host cell monolayers.

[0133] The low iron oxide, iron-doped titanium dioxide functionalized fiberglass swatches and control swatches are allowed to incubate at the selected temperature for the duration of the contact time.

[0134] At the close of the contact time, the low iron oxide, iron-doped titanium dioxide functionalized fiberglass and control swatches are neutralized. The harvest suspensions are serially diluted and each dilution is plated in quadruplicate to host cell monolayers.

[0135] The enumeration assay is allowed to incubate at the appropriate temperature for the test virus, usually for 7 days.

[0136] The enumeration assay is scored using standard cell culture techniques.

[0137] It is anticipated that the low iron oxide, iron-doped titanium dioxide functionalized fiberglass will reduce or eliminate the inoculum relative to the control.

[0138] While example embodiments have been described in connection with what is presently considered to be an example of a possible most practical and/or suitable embodiment, it is to be understood that the descriptions are not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the example embodiment. Those skilled in the art will recognize or be able to ascertain using no more than routine experimentation, many equivalents to the specific example embodiments specifically described herein. Such equivalents are intended to be encompassed in the scope of the claims, if appended hereto or subsequently filed.