Personal protective equipment to protect users from airborne pathogens

Abstract

A disposable or optically clear mask is provided that includes a mask body having a periphery and a strap attached to the mask body proximate the periphery for removably holding the mask on a user's face, the mask body having an inner layer made of a polymeric plastic material having a plurality of passages therethrough, the inner layer having an inner surface and an outer surface, and a porous glass filter functionalized with a visible light photocatalyst and abutting the outer surface of the inner layer. Also provided is a garment including glass fibers functionalized with a visible light photocatalyst.

Description

Technical Field

[0001] The present technology is directed to disposable or optically transparent masks and other clothing that can be worn by a user to protect the user from airborne microorganisms including bacteria, fungi, and viruses. More specifically, the mask kills a significant percentage of airborne microorganisms upon contact, captures the microorganisms, and minimizes restriction of airflow to the user.

Background Art

[0002] It is well known that in order to sterilize liquids and gases, the filter needs to have a pore size of 0.2 micrometers (microns) or less. Nevertheless, disposable masks for protecting against disease have much larger pore sizes. For example, the N95 mask, which is recommended as a mask for the general public to wear, has a pore size of 0.3 microns. As its name indicates, this mask is designed to remove 95% of particulate matter with a diameter of 0.3 microns or more. Unfortunately, many bacteria are smaller than 0.3 microns. For example, the diameter of Haemophilus influenzae is about 0.2 microns to about 0.3 microns. Generally, viruses are smaller than bacteria, and their diameters can range from 30 nanometers (0.03 microns) for poliovirus to 120 - 150 nanometers (0.120 - 0.150 microns) for HIV-1 virus. The COVID-19 virus has been reported to range in diameter from about 0.06 microns to about 0.14 microns. Based on the above, it is clear that N95 masks are insufficient to protect the user from some bacteria and most viruses, which are the most common pathogens.

[0003] Another problem with disposable masks is contamination. Even if the mask reduces the passage of pathogens from the surroundings to the user, the mask then becomes contaminated. If the mask is not properly discarded or reused, the mask then becomes a source of infection.

[0004] Another problem with disposable masks is airflow. Because the pore size restricts airflow, these masks are unsuitable for users with reduced lung capacity and respiratory problems such as shortness of breath. One study showed that breathing through N95 mask material hinders gas exchange and places an additional workload on the metabolic system. Specifically, N95 mask material reduced mean tidal volume by 23.0% (95% CI: -33.5% to -10.5%, p<0.001) and minute ventilation by 25.8% (95% CI: -34.2% to -15.8%, p<0.001), but there was no significant change in respiratory rate compared to breathing ambient air. Oxygen consumption (VO2) and carbon dioxide emissions (VCO2) also decreased significantly, with VO2 decreasing by 13.8% (95% CI: -24.2% to -3%, p=0.013) and VCO2 decreasing by 17.7% (95% CI: -28.1% to -8.6%, p=0.001).

[0005] Another problem with conventional disposable face masks is that they obscure the user's facial expressions and movements. This is particularly problematic for the hearing impaired or hard of hearing, as well as for those who rely on lip-reading to follow conversations.

[0006] In related technology, Patent Document 1 (U.S. Patent Application Publication No. 2019 / 0125011) discloses a disposable face mask that changes color as an indicator of fever, providing a rapid and inexpensive method for hospitals to triage infected patients while limiting exposure to others. While this may help in the rapid identification of infected patients, it does not address concerns regarding the use of disposable masks. Specifically, it does not address mask contamination, insufficient gas exchange, and incomplete capture of pathogens.

[0007] Patent Document 2 (U.S. Patent Application Publication No. 2017 / 0013894) discloses a disposable mask comprising a plastic bag, which can be easily disposed of by sealing the mask body in the plastic bag after use. This disposable mask includes an outer shell and lining integrally formed into a single body by heat bonding. This disposable mask includes a mask body having a rectangular shape and comprising a wire positioned on the upper side of the mask body to ensure a tight fit to the user's face according to the contours of the face, and earbands positioned on both sides of the mask body; and a plastic bag positioned on the upper side of the mask body between the outer shell and lining, which allows for the hygienic disposal of the mask body after use. This disposable mask addresses the contamination problem by providing a bag for storing a contaminated mask inside, but does not provide a means to kill pathogens and does not address insufficient gas exchange and incomplete capture of pathogens.

[0008] Patent Document 3 (International Publication No. 2018 / 064747) discloses the use of iron-doped titanium dioxide in wastewater purification, which concerns a method for producing a visible light photocatalyst. This method comprises the steps of: preparing iron-doped nanocrystals by doping titanium dioxide nanocrystals with iron; washing the iron-doped nanocrystals with acid to produce acid-washed iron-doped titanium dioxide nanocrystals; and rinsing the acid-washed iron-doped titanium dioxide nanocrystals to remove acid residue, thereby obtaining a visible light photocatalyst. The visible light photocatalyst is iron-doped titanium dioxide with low iron oxide content.

[0009] Patent Document 4 (U.S. Patent Application Publication No. 2020 / 0164616) discloses a nonwoven cellulose fiber fabric produced in particular directly from a lyocell spinning solution, the fabric comprising a substantially endless network of fibers, wherein several different fibers are at least partially located in different, distinguishable, interconnected layers, and the fabric is optically transparent when wet.

[0010] Patent Document 5 (U.S. Patent Application Publication No. 2020 / 0132899) discloses a substrate having transparency to infrared body radiation and opacity in the visible light spectrum, as well as a system and method for producing the same. The IR radiation-transparent substrate is IR radiation-transparent and visible light opacity and has sufficient breathability and flexibility to be suitable for use in clothing for thermoregulation. Furthermore, the IR radiation-transparent substrate is made using nanofiber technology, forming micropores of a specific size between the nanofibers.

[0011] Patent document 6 (U.S. Patent Application Publication No. 2019 / 0282460) discloses that nanofibers are being applied in fields where optical properties such as high transparency utilizing the nanoscale effect are required. For example, by making the diameter of the nanofibers smaller than the wavelength of visible light, a transparent fabric can be achieved.

[0012] Patent Document 7 (U.S. Patent Application Publication No. 2015 / 0177423) discloses opto textiles that utilize and leverage the photo-interaction properties of the fiber or yarn itself, as well as the photo-interaction properties of the entire fabric, so that the fabric exhibits, for example, a given appearance or provides a given visual effect, appropriately cools the wearer / user, appropriately warms the wearer / user, and / or fulfills a lifestyle or therapeutic function. In various exemplary embodiments, the present invention provides fibers, yarns, and fabrics that utilize, for example, light-matter interactions, fluorescence, phosphorescence, photochromism, thermochromism, and thermally activated luminescence to control and manipulate optical properties such as wavelength, propagation direction, coherence, and intensity so that the needs for a particular application can be met.

[0013] By using the present invention, it becomes possible to create a fabric, whether woven or nonwoven, that can be highly transparent and, when illuminated with light of a specific spectral component, allows an observer to see an object behind the fabric. The same fabric becomes colored and no longer transparent when illuminated with light having a different spectral component.

[0014] The ability to become transparent or opaque depends on the type of illumination light and the type of fluorescent nanoparticles used in the fabric. The absorption and emission properties of fluorescent nanoparticles are such that, as long as the incident light wavelength is shorter than the wavelength containing the emission spectrum of the fluorescent particles, light of a specific wavelength is selectively absorbed and converted into light of a different wavelength. For example, consider a shirt made of a material containing fluorescent nanoparticles that emit green light. Green fluorescence has a specific wavelength. The nanoparticles can absorb any light with a wavelength shorter than the wavelength of green fluorescence. Light with a wavelength longer than the wavelength of green fluorescence is not absorbed, and the material becomes effectively transparent with light of these wavelengths. The wavelength of light required to provide transparency is determined by the light source, such as sunlight or artificial lighting used in homes, and since no one can choose this wavelength, this property would not be suitable for masks or other clothing items.

[0015] Patent document 8 (U.S. Patent Application Publication No. 2010 / 0190401) discloses a transparent planar material for architectural purposes having several coatings. This coating system is selective for wavelengths that have high transmittance in the visible spectral region and high reflectance in the infrared spectral region. The coatings described above are metallic coatings and metallic oxide coatings.

[0016] Patent document 9 (U.S. Patent No. 5,665,450) discloses a glass ribbon-reinforced transparent polymer composite that provides excellent optical transparency and low strain levels over a wide temperature range, while exhibiting superior mechanical properties compared to glass fiber-unreinforced polymer composites and properties equivalent to those of glass fiber-reinforced polymer composites. These products are solids and are used in applications such as windshields.

[0017] Patent document 10 (U.S. Patent No. 7,320,713) discloses a method for producing ultrafine particle dispersion water of precious metals, in which ultrafine particles of precious metals are dispersed in water by burning precious metals using hydrogen and oxygen in high-pressure water, and then processing textile products with the obtained dispersion water of precious metal particles to obtain high-performance textile products, mainly clothing, which have excellent health-promoting and cleanliness-enhancing functions.

[0018] Face shields, such as those described in Non-Patent Document 1 (https: / / www.thedentalmarket.ca / infection / face-shield-protective-cover-transparent-1-pk / ?gclid=EAIaIQobChMItomGptL27AIViR-tBh29-AeYEAQYASABEgK8kPD_BwE), have been shown to be less effective at preventing disease transmission than disposable or reusable face masks. In fact, when used by medical and dental professionals, face shields are used in conjunction with disposable masks.

[0019] Patent Document 11 (Chinese Patent Publication No. 101532229) discloses a method for post-planarization treatment of electronic-grade glass fiber cloth, aiming to provide a method for post-planarization treatment of electronic-grade glass fiber cloth having good resin impregnation, good water resistance, good surface smoothness, and low permeability. This method comprises the following steps, namely: The steps include obtaining an unde-sizing glass fiber cloth after weaving on a jet loom, The steps include washing and immersing the cloth in a washing device with water at a temperature of 50-90°C, Pressure of 10-70 kg / cm² 2 The steps include flattening and shaping the fabric using a cooling pressure roller with a cooling water temperature of 5-25°C, The process involves, after flattening and shaping, winding the unde-sizing glass fiber cloth onto an iron core and directly performing a heat de-sizing process in a heated de-sizing furnace to obtain a flattened glass fiber cloth with an organic residue content of less than 0.04%, and, The steps include: performing a coupling agent immersion treatment using a vertical surface processing machine to obtain a flattened electronic-grade glass fiber cloth; This method can be widely applied in the field of electronic-grade glass fiber cloth. However, this product is not suitable for use in face masks due to its low breathability.

[0020] Patent document 12 (International Publication No. 2013 / 149400) discloses a processing method for flattening electronic-grade glass fiber cloth and an electronic-grade glass fiber cloth manufactured using this method. First, a sizing finish is performed by winding the yarn monofilaments onto a warp beam while sizing them, and then a thick glass fiber cloth is obtained by weaving the resulting warp threads together. Next, the obtained thick glass fiber cloth is placed in a steam oven for fumigation and swelling. Due to the effects of saturated steam ejection and fumigation in a high-temperature, high-humidity environment, the highly expandable starch between the yarns swells rapidly under heat and humidity, and when the yarn bundles are maintained in a high-temperature, high-humidity environment for a while, secondary structural rearrangement is formed, increasing the space between the yarn bundles. After that, the obtained swollen glass fiber cloth is continuously heated and degreased by boiling at high temperature. Finally, the obtained degreased glass fiber cloth is opened by high-pressure injection, excess moisture is removed by extrusion, and a silane coupling agent is impregnated using a surface treatment machine.

[0021] [Other personal protective equipment] A primary concern for personal protective clothing used in the healthcare industry is the spread of disease while the clothing is removed. Currently, care must be taken to remove the clothing so that the wearer's body does not come into contact with surfaces that may be contaminated with pathogens. When the clothing is removed and then rolled up and discarded, it must be turned inside out. After that, the wearer must thoroughly disinfect their hands. If not done correctly, the wearer may unknowingly transmit pathogens to themselves or others.

[0022] Personal protective clothing can include gloves, caps, gowns, booties, and trousers, with gloves and gowns being the most commonly used. In addition, face shields are also used to protect medical staff.

[0023] Patent Document 13 (U.S. Patent Application Publication No. 2019 / 0297967) discloses a disposable contact isolation gown for protecting against nosocomial infections. The contact isolation gown includes a front body having a front edge, a pair of front shoulder edges, a pair of front side edges, and a front bottom edge. The gown also includes a back body coupled to the front body by a pair of side seams. The back body has a back edge, a vulnerable back line extending from the back edge to the back bottom edge, and a pair of back body portions joined together by the vulnerable back line. The gown also includes a pair of sleeves coupled between the front body and the back body. Each sleeve has a sleeve back edge, a sleeve front edge, and a sleeve collar edge. This gown does not address gown contamination.

[0024] Patent Document 14 (U.S. Patent Application Publication No. 2018 / 0228227) discloses a disposable hospital gown aimed at enabling rapid donning and rapid removal without sacrificing protection from harmful and contaminating substances for providers / users. This does not address gown contamination.

Prior Art Documents

Patent Documents

[0025]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

[0026] [Non-Patent Document 1] https: / / www.thedentalmarket.ca / infection / face-shield-protective-cover-transparent-1-pk / ?gclid=EAIaIQobChMItomGptL27AIViR-tBh29-AeYEAQYASABEgK8kPD_BwE [Overview of the project] [Problems that the invention aims to solve]

[0027] What is needed is a face mask that kills a significant proportion of airborne microorganisms upon contact, captures remaining microorganisms, and minimizes restriction of airflow to the user. Disposable would be preferable. Low manufacturing cost would be preferable. Furthermore, it would be preferable that it fits snugly to the user's face, covering the chin, mouth, and nostrils. An optically transparent face mask that allows the user's facial expressions and movements to be seen would be even preferable. Lip-reading would be preferable. In addition, it would be preferable to provide a mask that kills a significant proportion of airborne pathogens upon contact and captures remaining pathogens. Furthermore, it would be preferable to provide clothing and face shields that kill a significant proportion of airborne pathogens upon contact. Means for solving the problem

[0028] This technology provides a face mask that kills a significant proportion of airborne microorganisms upon contact, captures remaining microorganisms, and minimizes restriction of airflow to the user. This face mask is disposable and inexpensive to manufacture. It fits snugly to the user's face, covering the chin, mouth, and nostrils. In one embodiment, the face mask is optically transparent, allowing for lip-reading.

[0029] In one embodiment, a disposable mask is provided, comprising a mask body having a periphery, and a strap attached to the mask body near the periphery to detachably hold the mask on the user's face, wherein the mask body comprises an inner layer made of a polymer plastic material having a plurality of passages penetrating the inner layer, and having an inner surface and an outer surface, and a porous glass filter functionalized with a visible light photocatalyst and in contact with the outer surface of the inner layer.

[0030] In disposable masks, the visible light photocatalyst may be low-iron oxide iron-doped titanium dioxide nanoparticles.

[0031] In a disposable mask, the porous glass filter may be located within a filter region bounded by a boundary region, the boundary region may include an inner layer and extend from the filter region to the periphery.

[0032] In disposable masks, the porous glass filter may be made of glass fiber fabric.

[0033] In disposable masks, low-iron oxide iron-doped titanium dioxide nanoparticles may have a surface that is almost free of iron oxide.

[0034] In a disposable mask, the mask body may further include a moldable edge portion that is close to the peripheral edge of the inner surface of the inner layer.

[0035] In a disposable mask, the mask body may further have a transparent outer cover made of a polymer plastic material having multiple passages that penetrate the outer cover, and the outer cover may come into contact with a glass fiber filter.

[0036] In a disposable mask, the mask body may further have a filter layer, and the filter layer may be in contact with the outer surface of the inner layer.

[0037] In disposable masks, the filter layer may be composed of unbonded plastic polymer fibers.

[0038] In one embodiment, a face mask is provided having an optically transparent or optically translucent mask body. The face mask comprises a peripheral portion around the edge of an optically transparent or optically translucent mask body, and a strap attached to the mask body close to the peripheral portion to detachably hold the mask on the user's face, wherein the mask body comprises an inner layer which is an optically transparent or optically translucent material having an inner surface and an outer surface and having a plurality of passages penetrating the inner layer, and a glass fiber fabric layer which abuts the outer surface of the inner layer and includes a glass fiber ribbon.

[0039] In face masks, the glass fiber fabric may be functionalized with a visible light photocatalyst.

[0040] In a face mask, the refractive index of the optically transparent or optically translucent material of the inner layer and the refractive index of the glass fiber ribbon in the glass fiber fabric layer may be relatively within the range of about 0.06.

[0041] In a face mask, the visible light photocatalyst may be iron-doped titanium dioxide with low iron oxide content.

[0042] In face masks, low-iron oxide iron-doped titanium dioxide may also be in the form of nanoparticles.

[0043] In a face mask, low-iron oxide iron-doped titanium dioxide nanoparticles may have a surface that is almost free of iron oxide.

[0044] In a face mask, the mask body may further have a moldable edge close to the peripheral edge.

[0045] In a face mask, the mask body may have an outer cover made of an optically transparent or optically translucent material having multiple passages that penetrate the outer cover, and which is in contact with a glass fiber layer.

[0046] In a face mask, the refractive index of the optically transparent or optically translucent material of the outer cover, the refractive index of the optically transparent or optically translucent material of the inner layer, and the refractive index of the glass fiber ribbon of the glass fiber fabric layer may be relatively within the range of about 0.060.

[0047] In a face mask, the mask body may further include an optically transparent or optically semi-transparent filter layer, and the filter layer may be located between the outer surface of the inner layer and the glass fiber fabric layer.

[0048] In a face mask, the optically transparent or optically translucent filter layer may be composed of unbonded plastic polymer fibers.

[0049] In a face mask, the refractive index of the unbonded plastic polymer fibers, the refractive index of the optically transparent or optically translucent material of the outer cover, the refractive index of the optically transparent or optically translucent material of the inner layer, and the refractive index of the glass fiber ribbon of the glass fiber fabric layer may be relatively within the range of about 0.060.

[0050] In a face mask, the inner layer may contain silk fibroin or rayon material.

[0051] In a face mask, the inner layer may be made of silk fibroin material.

[0052] In a face mask, the outer layer may contain silk fibroin or rayon material.

[0053] In a face mask, the outer layer may be made of silk fibroin material.

[0054] In a face mask, the mask itself may be optically transparent.

[0055] In a face mask, the glass fiber fabric layer may consist of glass fiber ribbons functionalized with low iron oxide iron-doped titanium dioxide nanoparticles, having a surface that is almost free of iron oxide.

[0056] Another embodiment provides a method for manufacturing an optically translucent or optically transparent mask body for a face mask, the method comprising the steps of: selecting a glass fiber material consisting of a glass fiber ribbon functionalized with low iron oxide iron-doped titanium dioxide nanoparticles; shaping the glass fiber material into the form of a mask body; selecting an inner layer consisting of an optically transparent or optically translucent material having a refractive index of 0.06 or less relative to the refractive index of the glass fiber material; shaping the optically translucent material into the form of a mask body; and attaching the inner layer to the glass fiber material, thereby manufacturing an optically translucent or transparent mask body.

[0057] This method further comprises the steps of selecting an outer layer made of an optically transparent or optically translucent material having a refractive index of 0.06 or less relative to the refractive index of the glass fiber material and the inner layer, and attaching the outer layer to the glass fiber material to manufacture an optically translucent or transparent mask body.

[0058] In this method, the mask itself can reduce the average tidal volume by approximately 16.2% or less.

[0059] Another embodiment provides a personal protective clothing article comprising a glass fiber fabric functionalized with a visible light photocatalyst.

[0060] In articles, the visible light photocatalyst may be low iron oxide iron-doped titanium dioxide nanoparticles.

[0061] In articles, low iron oxide iron-doped titanium dioxide nanoparticles may have a surface that is almost free of iron oxide.

[0062] The items may be selected from a group consisting of a cap, a gown, a hooded gown, a pair of booties, and trousers.

[0063] In another embodiment, a face shield is provided, comprising a band and a transparent visor attached to the band, the transparent visor being functionalized with visible light.

[0064] In face shields, the visible light photocatalyst may be low-iron oxide iron-doped titanium dioxide nanoparticles.

[0065] In a face shield, low-iron oxide iron-doped titanium dioxide nanoparticles may have a surface that is almost free of iron oxide. [Brief explanation of the drawing]

[0066] [Figure 1] This is a perspective view of a disposable mask using this technology. [Figure 2] This is a cross-sectional view taken through line AA in Figure 1. [Figure 3] This is a cross-sectional view of an alternative embodiment passing through line AA in Figure 1. [Figure 4] Figure 1 shows the inside view of a disposable mask. [Figure 5] This is a cross-sectional view of an alternative embodiment shown in Figure 1. [Figure 6] This is a schematic diagram illustrating gas exchange between the user and the surrounding environment. [Figure 7] This is a schematic diagram of a glass fiber fabric or glass fiber ribbon functionalized with low iron oxide iron-doped titanium dioxide nanoparticles. [Figure 8A] This is an inside view of a disposable mask in an alternative embodiment. [Figure 8B] This is a cross-sectional view of the disposable mask in Figure 8A along line 8B-8B. [Figure 9] This is a block diagram showing the manufacturing process of fiberglass ribbons and the resulting fabrics. [Figure 10] This block shows another method for manufacturing fiberglass ribbon and the resulting fabric. [Figure 11] This is a schematic diagram of clothing made from functionalized glass fiber fabric. [Figure 12] This is a schematic diagram of a face shield. [Modes for carrying out the invention]

[0067] Unless otherwise explicitly provided, the following rules of interpretation apply to this specification (the description and claims). (a) All terms and phrases in this specification shall be interpreted as having gender and number (singular or plural) as required by the context. (b) The singular terms “a, an” and “the” used in the specification and the attached claims include a plural noun unless the context otherwise explicitly states. (c) The antecedent “about” applied to any listed range or value represents a deviation within a range or value known or expected in the art from the measurement method. (d) Unless otherwise specified, “herein, hereby, hereof, hereto, hereinbefore and hereinafter” and similar words refer to the entire Specified (e) Explanatory headings are for convenience only and do not govern or affect the meaning or structure of any part of this specification. (f) "or" and "any" are not mutually exclusive, and "include" is not restrictive. Furthermore, unless otherwise specified, the terms "comprising," "having," "including," and "containing" are interpreted as unrestricted terms (i.e., "including, but not limited to.")

[0068] The enumeration of numerical ranges in this specification is intended solely as an abbreviation for referring individually to separate values ​​that fall within that range, unless otherwise specified herein, and each separate value is incorporated into the specification as if it were individually enumerated herein. Where a particular range of values ​​is given, unless the context explicitly states otherwise, it is understood that each value between the upper and lower limits of that range, up to one-tenth of the lower limit, and any other stated or intermediate values ​​within that range are included within that range. All smaller sub-ranges are also included. Furthermore, the upper and lower limits of these smaller ranges are also included, subject to any specifically excluded limits within the range.

[0069] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art. Any methods and materials similar or equivalent to those described herein may also be used, but only acceptable methods and materials are described herein.

[0070] <Definition>

[0071] Pathogen: In the context of this technology, a pathogen is a living microorganism that causes disease. Pathogens include, but are not limited to, bacteria, fungi, or viruses.

[0072] Aerosol: In the context of this technology, an aerosol is a suspended solid / liquid particle in a gas.

[0073] Glass fiber fabric: In the context of this technology, glass fiber fabric is composed of plain-woven glass yarn. The fabric has an arbitrary thread count, for example, 20×14, 60×52, or 70×70, and an arbitrary thickness, for example, 2.5 microns to 250 microns, although this is not limited. The porosity of the final product is determined by the thread count and yarn thickness.

[0074] Iron-doped titanium dioxide having a low iron oxide surface: In the context of this technology, iron-doped titanium dioxide having a low iron oxide surface, as observed by X-ray photoelectron spectroscopy, has on its surface about 0.1 atomic% to about 2.0 atomic% iron, preferably 0.25 atomic% to about 0.75 atomic% iron, more preferably 0.5 atomic% iron and a very small amount of iron oxide (less than 5% of the surface is iron oxide).

[0075] Glass fiber ribbon: In the context of this technology, a glass fiber ribbon is a flattened fiber of a certain length.

[0076] Planarized Fibers, Glass Fiber Fabric: In the context of this technology, glass fiber fabric consists of plain-woven glass yarn. The glass yarn has an arbitrary thread count, for example, not limited to 20×14 to 60×52 or 70×70, and an arbitrary thickness, for example, not limited to 2.5 microns to 250 microns. The porosity of the final product is determined by the thread count and the thickness of the yarn. The glass yarn, also known as fibers, is all planarized into ribbons on a single plane, and this plane is parallel to the upper and lower surfaces of the face mask.

[0077] Optically transparent: In the context of this technology, optically transparent means that an image can be seen through the material.

[0078] Nearly iron oxide-free surface: In the context of this technology, a nearly iron oxide-free surface, as observed by X-ray photoelectron spectroscopy, has an iron oxide content equivalent to less than 0.001% iron atoms (less than 0.5% of the surface is iron oxide).

[0079] Fluid: In the context of this technology, a fluid is a gas, a liquid, or both.

[0080] Levitation: In the context of this technology, levitation includes aerosols and particles in the air.

[0081] Porous glass filter layer: In the context of this technology, the porous glass filter layer is a layer of glass fiber fabric or a layer of sintered glass.

[0082] <Detailed explanation> A disposable mask, generally referred to as reference numeral 10, is shown in Figure 1. The mask comprises a mask body 12, a nose piece 14, and two straps 16. The nose piece 14 is moldable and preferably made of aluminum or a flexible plastic that maintains its shape when fitted to the user's nose. The straps 16 are preferably made of elastomer and are held in place by the mask body 12. The mask body 12 has sufficient elasticity to maintain its shape during use. Its shape may be cup-shaped, as shown in the figure.

[0083] As shown in Figure 2, the mask body 12 is layered, having an outer cover 20, a glass fiber filter layer 22, and an inner layer 24. Preferably, the outer cover 20 is polyester or another plastic polymer and is transparent to visible light. This polyester or other plastic polymer is made of fibers that are bonded or woven together to provide passages. The glass fiber filter layer 22 is woven. This layer is functionalized with low iron oxide iron-doped titanium dioxide nanoparticles. The inner layer 24 is polyester or another woven plastic polymer. This polyester or other plastic polymer is made of fibers that are bonded or woven together to provide passages. The nasal foam 26 is attached to the inner layer 24 below the nose piece 14.

[0084] In an alternative embodiment, the outer cover 12 is made of silk fibroin material. The outer cover 12 may be woven, or it may be printed three-dimensionally or lithographically to obtain an appropriate pore size.

[0085] In another embodiment shown in Figure 3, the mask body is layered, having an outer cover 20, a glass fiber filter layer 22, a filter layer 30, and an inner layer 24. The outer cover 20 is preferably polyester or another plastic polymer and is transparent to visible light. In one embodiment, the outer cover 20 is optically transparent. This polyester or other plastic polymer is made from fibers that are bonded or woven together to provide passages. The glass fiber filter layer 22 is woven. In one embodiment, this layer is optically transparent. This layer is functionalized with low iron oxide iron-doped titanium dioxide nanoparticles. Preferably, the filter layer 30 is not bonded or woven and is made from plastic polymer fibers that also provide passages. The inner layer 24 is polyester or another woven plastic polymer. In one embodiment, the inner layer 24 is optically transparent. This polyester or other plastic polymer is made from fibers that are bonded or woven together to obtain passages. The nasal foam 26 is attached to the inner layer 24 below the nose piece 14.

[0086] In another embodiment shown in Figure 4, a moldable edge 42 is provided around the periphery of the mask body 12 (generally referred to as reference numeral 40). The moldable edge 42 is flexible and can conform to the user's face. Preferably, the moldable edge 42 is a thin layer (about 1 mm to about 3 mm) of foam or silicone rubber. The moldable edge 42 reduces the possibility of air flowing between the disposable mask 10 and the user's face.

[0087] In another embodiment shown in Figure 5, the mask body 12 is layered, having a glass fiber filter layer 22 and an inner layer 24. The glass fiber filter layer 22 is woven and optically transparent. This layer 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. This plastic polymer material or rayon material is made from fibers that are bonded or woven together to provide a passage. The nasal foam 26 is attached to the inner layer 24 below the nose piece 14.

[0088] As an example, Figure 6 shows the inflow and outflow of gas into a disposable or transparent mask using the embodiment shown in Figure 3. The passages in the outer cover 20 and inner layer 24 are large enough to minimize the impact on gas exchange. Therefore, the passages are about 0.3 microns to about 0.9 microns, preferably about 0.6 microns to about 0.9 microns. If present, the inner filter layer 30 has passages of about 0.3 microns to about 0.9 microns, preferably about 0.6 microns to about 0.9 microns.

[0089] As shown in Figure 7, the glass fiber filter layer 22 has interstitial spaces 50 between the woven fibers 52. Nanoparticles 54 are attached to the woven fibers 52. The weaving method shown is one over one, but other weaving methods are also possible. The interstitial spaces 50 have a width of about 0.5 microns to about 1.0 micron, preferably about 0.9 microns.

[0090] In one embodiment, the glass fibers are planarized as a ribbon 52 along a single plane 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 glass fiber ribbon, thus maximizing optical clarity. When different materials, including plastic polymer, rayon, or silk fibroin, are used in the layers, these materials match the refractive index of both the glass fiber ribbon 50 and the other layers. Specifically, the refractive index of the plastic polymer is within approximately 0.010 of the refractive index of the glass fiber ribbon at wavelengths of approximately 380 nm to approximately 700 nm.

[0091] The following table shows plastic polymers and their refractive indices that may impart transparency when used in fiberglass fabrics.

[0092] [Table 1]

[0093] Other possible materials include, but are not limited to, silk fibroin with a refractive index of 1.54 or rayon with a refractive index of 1.54 to 1.55.

[0094] In alternative embodiments, the refractive index of the plastic polymer material is within 0.1, preferably within 0.06, and most preferably within 0.03, relative to the refractive index of the borosilicate glass, and the mask body 12 is optically semi-transparent.

[0095] [Table 2-1] [Table 2-2]

[0096] As shown in Figure 8A, in an alternative embodiment, the mask body 12 has a sintered glass region 100 bounded by a boundary region 102. The boundary region 102 is flexible, allowing the mask body 12 to conform closely to the user's face and cover the mouth, chin, and nose. The mask body 12 may or may not include a moldable edge 42. As shown in Figure 8B, the sintered glass region 100 includes at least a functionalized sintered glass filter layer 104 and an inner layer 24. The outer cover 20 is optional and, if present, light-transmitting. The boundary region 102 includes at least the outer cover 20 and the inner layer 24, and may also include a filter layer 30. The functionalized thin sintered glass filter layer 104 is about 2 to 20 microns thick. Since the thickness determines flexibility, therefore, a minimum thickness is desirable. The flexibility of the functionalized thin sintered glass layer 104 is such that it can bend to an effective radius of less than 20 centimeters, preferably less than 5 centimeters, more preferably less than 1 centimeter, most preferably less than 0.5 centimeters, or some equivalent dimension. The thin sintered glass is functionalized after sintering.

[0097] In another embodiment, the sintered glass region is replaced with a glass fiber region instead of a glass fiber filter layer having the same dimensions as the mask body 12. This glass fiber region has functionalized glass fibers sandwiched at least between the outer cover and the inner layer.

[0098] In another alternative embodiment, there is no outer cover, and the outermost layer is a glass fiber filter layer.

[0099] In yet another alternative embodiment, the outermost layer is a glass fiber filter layer. A standard disposable mask is attached to the inner surface of the glass fiber filter layer. This embodiment does not address the poor gas exchange of the standard mask.

[0100] In all embodiments, the glass fiber filter layer is separated from the user's face by at least an inner layer, which captures any nanoparticles or glass fibers that may detach from the glass fiber filter layer.

[0101] Figure 9 shows one method for preparing an optically transparent fiberglass fabric. A borosilicate glass boule is heated to approximately 1200°C (step 100). The fiberglass is drawn out (step 102) to form a viscous liquid yarn. Once the drawn-out viscous liquid yarn has cooled (step 104), it is passed through a hot roller (step 106) to flatten the fibers into a ribbon (step 108). The fiberglass ribbon is then woven together with other flattened ribbons to create an optically transparent fiberglass fabric (step 110). The optically transparent fiberglass fabric is then wrapped around a column to create one roll of fabric (step 112).

[0102] Figure 10 shows a second method for preparing an optically transparent fiberglass fabric. The pre-made fiberglass fabric is heated to approximately 1100°C (step 120) to make the fibers an amorphous solid. The fiberglass is passed through a hot roller (step 122) to flatten the fibers in the fabric into a ribbon (step 124). Then, the optically transparent fiberglass fabric is wrapped around a column to make one roll of fabric (step 126).

[0103] Functionalized glass fiber fabrics, functionalized optically transparent glass fiber fabrics, or functionalized sintered glass are functionalized with iron-doped titanium dioxide, preferably containing about 0.5 atomic percent of iron, but the iron content may be about 0.1 atomic percent to about 2.0 atomic percent, with low iron oxide or nearly iron oxide-free content.

[0104] In another embodiment, the functionalized glass fiber fabric is about 50 microns to about 1 mm thick, preferably 60 microns thick, and is used for personal protective clothing. As shown in Figure 11, the clothing items include a cap 200, a gown 202, booties 204, a hooded gown 206, and pants 208.

[0105] The functionalized glass fiber fabric or functionalized sintered glass is functionalized with iron-doped titanium dioxide, which preferably contains about 0.5 atomic percent of iron, but may contain about 0.1 atomic percent to about 2.0 atomic percent of iron, and is low in iron oxide or nearly iron-free.

[0106] As shown in Figure 12, the glass or plastic face shield, generally referred to by reference numeral 210, includes a band 212 and a visor 214. The visor 214 is functionalized with iron-doped titanium dioxide, which preferably contains about 0.5 atomic percent of iron, but may contain about 0.1 atomic percent to about 2.0 atomic percent of iron, and is low in iron oxide or nearly iron-free.

[0107] The plastic or glass goggles have lenses functionalized with low-iron oxide or nearly iron-free iron-doped titanium dioxide, preferably containing about 0.5 atomic percent iron, but which may be about 0.1 atomic percent to about 2.0 atomic percent iron.

[0108] One method for preparing low-iron oxide iron-doped titanium dioxide-functionalized glass fibers, functionalized optically transparent glass fiber fabrics, or sintered glass is as follows:

[0109] Iron-doped titanium dioxide nanoparticles were prepared by the sol-gel method using titanium isopropoxide (TTIP) as a precursor and ferric nitrate (Fe(NO3)3·9H2O) as an iron source. First, desired amounts of ferric nitrate (0.25, 0.5, 1, 5, and 10 mol%) were 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 approximately pH 3 (approximately pH 2.5 to approximately pH 3.5) using HNO3 (other acids can also be used), thereby enabling better production of Fe-doped TiO2, i.e., Fe incorporation into TiO2 nanocrystals. Next, TTIP was added dropwise to the solution. Then, deionized water with a Ti:H2O ratio of 1:4 was added to the mixture. The solution was stirred for 2 hours, poured into a glass fiber fabric, and then dried at 80°C to form particles on the glass fiber fabric. Next, the mixture of these particles and the glass fiber fabric was washed three times with deionized water. Then, the mixture was fired at 400°C for 4 hours to attach the iron-doped titanium dioxide nanoparticles to the glass fibers of the fabric, thereby producing functionalized glass fibers. The functionalized glass fibers were washed in an HCl solution (acid washing), and then washed three times with deionized water. The acid washing was carried out in a solution with a pH of approximately 2.5 to approximately 3.5, or approximately 4, preferably using a monobasic acid, such as, 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 preferred. Through analysis, it was shown that the nanoparticles bonded to the glass fibers or sintered glass. The bond between the glass and Fe-doped TiO2 was not a bond between Si ions and Ti ions, but a bond between O ions.

[0110] A second method for preparing low-iron oxide iron-doped titanium dioxide-functionalized glass fibers, functionalized optically transparent glass fiber fabrics, or sintered glass is as follows:

[0111] Low iron oxide iron-doped titanium dioxide nanoparticles were prepared by the sol-gel method using titanium isopropoxide (TTIP) as a precursor and ferric nitrate (Fe(NO3)3·9H2O) as an iron source. First, desired amounts of ferric nitrate (0.25, 0.5, 1, 5, and 10 mol%) were 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 approximately pH 3 (approximately pH 2.5 to approximately pH 3.5) using HNO3 (other acids can also be used), thereby enabling better generation of Fe-doped TiO2, i.e., Fe incorporation into TiO2 nanocrystals. Next, TTIP was added dropwise to the solution. Then, deionized water with a Ti:H2O ratio of 1:4 was added. The solution was stirred for 2 hours and then dried at 80°C for 2 hours.

[0112] Next, the powder was washed three times with deionized water. Then, the powder was calcined at 400°C for 3 hours. The calcined powder was stirred in an HCl solution (acid washing), and then washed three times with deionized water. The acid washing was carried out in a solution with a pH of approximately 2.5 to approximately 3.5, or approximately 4, preferably using a monobasic acid, such as, 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 preferred. Low iron oxide iron-doped titanium dioxide was produced by acid washing. The low iron oxide iron-doped titanium dioxide nanoparticles were suspended in water and sprayed onto a glass fiber fabric or sintered glass, or the glass fiber fabric or sintered glass was immersed in water. A combination of glass fiber fabric and low-iron oxide iron-doped titanium dioxide nanoparticles was fired at 400°C for 4 hours, causing the low-iron oxide iron-doped titanium dioxide nanoparticles to adhere to the glass fibers in the fabric, thereby creating functionalized glass fibers. Analysis showed that these nanoparticles bond to the glass fibers or ribbons. The bond between the glass and Fe-doped TiO2 is not a bond between Si ions and Ti ions, but rather a bond between O ions.

[0113] A third method for preparing optically transparent, low-iron oxide iron-doped titanium dioxide-functionalized glass fibers is as follows: Using sputter deposition, 99.999% pure iron (produced by electrolytic refining) and 99.999% pure titanium dioxide are mixed together as an epitaxial layer on a glass fiber fabric. 99.999% pure argon, nitrogen, or xenon is used as the ionizing gas. A thin epitaxial layer of titanium dioxide is deposited, followed by an epitaxial layer of iron and a second epitaxial layer of titanium dioxide. One method adopted to control the amount of deposition to some extent involved depositing 100 nm of titanium dioxide, then 10 nm of iron, and then another 100 nm of titanium dioxide to achieve an epitaxial layer thickness of 210 nm. Next, this was annealed to homogenize the iron in the titanium dioxide, producing materials of 4.7 vol% iron-doped titanium dioxide or 8.7 wt% iron-doped titanium dioxide. By adjusting the thickness of the deposited iron epitaxial layer sandwiched between the titanium epitaxial layers, it is possible to synthesize iron doping within a certain range of concentrations. This method does not require acid washing.

[0114] In an alternative embodiment, a face mask 10 is provided having an optically translucent or optically transparent mask body 12, which includes a glass fiber fabric layer composed of glass fiber ribbons. The glass fiber ribbons and glass fiber fabric are not functionalized.

[0115] The mask body 12 is manufactured by selecting materials suitable for the inner and outer layers from the viewpoint of light transmission, and then confirming that their refractive index is sufficiently close to that of the glass fiber material. Once selected, the material is shaped (by cutting and potentially molding) into the form of the mask body 12. Either before or after shaping, the layers are attached to each other to obtain the mask body.

[0116] Regardless of the method used to fabricate the low-iron-oxide iron-doped titanium dioxide nanoparticle-functionalized glass fiber fabric, acid washing has been shown to remove a significant amount of iron oxide from the nanoparticle surface. The acid-washed iron-doped titanium dioxide nanoparticles function as catalysts under visible light.

[0117] The following are methods for reducing or eliminating airborne pathogens:

[0118] The user places a disposable mask or optically transparent mask of any of the embodiments described above over their mouth, nose, and chin, and places the elastomer straps around their ears or head, crimping the nose piece in a wavy shape to fit the shape of the user's nose. The user ensures there are no gaps between the user and the mask. When properly fitted, the mask covers part of the nose, including the nostrils, part of the cheeks, and part of the chin. The user breathes normally. When the air exhaled by the user is moist and the functionalized glass fiber layer is exposed to visible light, the nanoparticles act as a photocatalyst. Although not bound by theory, low iron oxide iron-doped titanium dioxide generates electrons and holes when exposed to visible light. Electrons combine with Fe+3 in the low iron oxide iron-doped titanium dioxide to form Fe+2, and holes combine with Fe+3 to form Fe+4. Fe+2 ions react with O2 in the air to form superoxide, an oxidation radical. Fe+4 ions react with OH ions from water in the air to form hydroxyl radicals. Therefore, moist air exhaled by the user initiates this reaction in the presence of visible light. The radicals then inhibit pathogen growth or eliminate pathogens. Even if there is insufficient moisture in the air during inhalation, the reaction can be triggered by moisture retained within the mask. The moisture is retained by the inner layer adjacent to the functionalized glass fiber layer, thereby allowing the functionalized glass fiber layer to absorb the moisture.

[0119] <Example 1> The mask in Figure 2, which has only one filter layer, reduced the average tidal volume by an average of 13.7% and the average minute ventilation by an average of 15.2% in a sample of five users.

[0120] <Example 2> The mask in Figure 3 has two filter layers and reduced the average tidal volume by an average of 16.2% in a sample of five users, and reduced the minute volume by an average of 18.4% in a sample of five users.

[0121] <Example 3> Low iron oxide iron-doped titanium dioxide-functionalized glass fibers or functionalized optically transparent glass fiber fabrics were tested for their virucidal activity. Surrogate coronaviruses, mouse hepatitis virus (MHV), and infectious gastroenteritis virus were used in the AATCC100 test with the viruses modified as follows.

[0122] Low iron oxide iron-doped titanium dioxide-functionalized glass fibers or functionalized optically transparent glass fiber fabrics, as well as control (unfunctionalized) glass fiber fabrics, are cut into samples of a size suitable for study.

[0123] Carefully apply 1.0 ml of the inoculant to the low-iron oxide iron-doped titanium dioxide-functionalized glass fiber and the control sample, ensuring that the suspension comes into contact only with the fabric. The inoculant must be completely absorbed so that more samples can be added as needed.

[0124] Additionally, to serve as a "zero-hour" control, 1.0 ml of the inoculant is applied to a separate set of untreated cotton samples.

[0125] The "zero time" control is immediately neutralized in a suitable medium. The suspension is diluted stepwise, and each dilution is applied to a monolayer of host cells in four different ways.

[0126] During the contact time, low-iron oxide iron-doped titanium dioxide-functionalized glass fiber samples and control samples can be cultured at a selected temperature.

[0127] At the end of the contact time, the low-iron oxide iron-doped titanium dioxide-functionalized glass fibers and the control sample are neutralized. The recovered suspension is diluted stepwise, and each dilution is applied to a monolayer of host cells in four different ways.

[0128] Enumeration assays typically involve culturing the test virus at an appropriate temperature for 7 days.

[0129] The counting assay is scored using standard cell culture techniques.

[0130] Low-iron oxide iron-doped titanium dioxide-functionalized glass fibers are expected to reduce or eliminate inoculants compared to the control.

[0131] While exemplary embodiments are described in relation to what is currently considered to be the most practical and / or appropriate possible embodiments, it should be understood that this description is not to be limited to the disclosed embodiments, but rather intended to encompass various variations and equivalent configurations that fall within the spirit and scope of the exemplary embodiments. Those skilled in the art will be able to identify or confirm many equivalents of the specific exemplary embodiments described herein by means of conventional experimentation alone. Such equivalents, if appended to this specification or filed after filing, are intended to be included in the claims.

Claims

1. In disposable masks, A mask body having a peripheral edge, and A strap is attached to the mask body near the periphery so as to removably hold the mask on the user's face, Equipped with, The aforementioned mask body is An inner layer, a polymer plastic material having a plurality of passages penetrating the inner layer, having an inner surface and an outer surface, the inner layer and, A porous glass filter functionalized with low iron oxide iron-doped titanium dioxide nanoparticles, which contacts the outer surface of the inner layer, and The outer cover is transparent and has multiple passages that penetrate the outer cover, and the outer cover is in contact with the porous glass filter, A disposable mask having [the following features].

2. A disposable mask according to claim 1, wherein the diameter of the passage in the inner layer and the passage in the transparent outer cover are 0.3 to 0.9 microns.

3. A disposable mask according to claim 2, wherein the porous glass filter defines a filter region bounded by a boundary region, the boundary region is composed of the inner layer and extends from the filter region to the periphery.

4. A disposable mask according to claim 2 or 3, wherein the porous glass filter is a glass fiber fabric.

5. A disposable mask according to any one of claims 1 to 4, wherein the low iron oxide iron-doped titanium dioxide nanoparticles have a surface that is substantially free of iron oxide.

6. A disposable mask according to any one of claims 1 to 5, wherein the mask body further has a moldable edge portion adjacent to the peripheral edge of the inner surface of the inner layer.

7. A disposable mask according to any one of claims 1 to 6, wherein the transparent outer cover is made of a polymer plastic material.

8. A disposable mask according to any one of claims 1 to 7, wherein the mask body further comprises a filter layer, and the filter layer is in contact with the outer surface of the inner layer.

9. A disposable mask according to claim 8, wherein the filter layer is made of unbound plastic polymer fibers.

10. A disposable mask according to any one of claims 1 to 3, wherein the porous glass filter is sintered glass.

11. A disposable mask according to claim 4, wherein the glass fiber fabric includes interstitial spaces having a width of 0.5 to 1.0 microns.

12. A disposable mask according to any one of claims 1 to 6, wherein the transparent outer cover is made of silk fibroin material.

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