CN115443080A - Anti-pathogen mask - Google Patents

Abstract

An antiviral mask and a method of using the same for inactivating a virus in contact with the mask are described herein. The mask may comprise: a fiber material impregnated with silicon nitride powder; and a layer surrounding the fibrous material. In some embodiments, the silicon nitride is present in the fibrous material at a concentration of about 1wt.% to about 15 wt.%.

Description

Anti-pathogen mask

Cross Reference to Related Applications

This application claims priority from U.S. provisional application No. 63/009,842, filed on day 14, month 4, 2020; the contents of the U.S. provisional application are incorporated herein by reference in their entirety.

Technical Field

The present disclosure relates to antiviral, antibacterial, and antifungal compositions, systems, methods, and devices. More particularly, the present disclosure relates to silicon nitride compositions, devices and coatings for inactivation and lysis of viruses, bacteria and fungi.

Background

There is a general need for safe and reliable inactivation, removal or lysis of viruses, bacteria and fungi. There is a wide need to control pathogens that affect human health. There is a need for materials with anti-pathogenic properties for human pharmacotherapy but also for the use of anti-pathogenic surface coatings and/or composites for various medical devices or equipment, examination tables, clothing, filters, masks, gloves, catheters, endoscopic instruments, and the like.

Masks and respirators are generally limited to single use because pathogens trapped on the filter can cause cross-contamination, new aerosol release and contaminated waste because they can survive on a surface for hours to days. Airborne particles are considered to be the major transmission pathway for pathogens such as influenza and SARS-CoV-2. Face coverings are critical to source control, but most masks produced today are simple filtering devices. Viral particles trapped in the mask not only contaminate the wearer during routine use, but are also re-aerosolized during adjustment or removal of the mask; and a contaminated mask is a significant biohazard to disposal. This is unfortunate because viral survival on surgical masks and respirators is clinically preventable. For example, copper has been used in general hospital and household goods for centuries because of its antimicrobial properties. It has been incorporated into surgical masks, but is toxic at concentrations above the nutrient level. Several other antiviral agents have also been proposed for use in masks or respirators. The antiviral agent comprises silver, zinc, iodine, chitosan, a peptide, a quaternary ammonium salt, and nanoparticles. The effectiveness of most of these compounds has not been clinically proven and their value remains questionable as they may be toxins, allergens, irritants or their bacterial or virucidal efficacy is limited or expensive.

Therefore, there is a need for a safe and reliable method for inactivating and killing viruses, bacteria and fungi that can be applied to masks, medical devices, equipment, clothing or other systems that may be in contact with the human body for extended periods of time.

Disclosure of Invention

Embodiments of an anti-viral mask for inactivating viruses and/or preventing the spread of viruses are provided herein. In one aspect, the facepiece can comprise a facepiece body comprising a fibrous material, wherein the silicon nitride powder is impregnated in the fibrous material. In some embodiments, the mask body may include an outer layer surrounding the fibrous material. In some embodiments, the silicon nitride may be present in the fibrous material at a concentration of about 1wt.% to about 15wt.%, and the silicon nitride inactivates viruses that come into contact with the fibrous material of the anti-viral mask. In some aspects, the silicon nitride in the fibrous material is present at a concentration of less than about 10 wt.%.

The mask body may be made of a fibrous material such that when droplets or aerosols containing the virus are captured by the mask fibers, the silicon nitride powder inactivates the virus. The virus may be in contact with the silicon nitride powder for at least 1 minute.

Also provided herein are embodiments of an antiviral mask comprising a mask body and one or more filters in the mask body, each filter comprising at least one layer, wherein silicon nitride powder is impregnated in the layer. The silicon nitride may be present in a concentration of about 1wt.% to about 15wt.% and inactivates viruses in contact with the one or more filters of the anti-viral mask. In some aspects, the silicon nitride in each filter is present at a concentration of less than about 10 wt.%.

The mask body and/or one or more filters are made of a fibrous material such that when droplets or aerosols containing the virus are captured by the one or more filters, the silicon nitride powder inactivates the virus. The virus may be in contact with the silicon nitride powder for at least 1 minute.

A method of preventing the spread of a virus is also described. The method can comprise contacting an antiviral facial mask with the virus, wherein silicon nitride powder is impregnated in the fibrous material of the facial mask at a concentration of about 1wt.% to about 15 wt.%. In some aspects, the silicon nitride in the fibrous material is present at a concentration of less than about 10 wt.%. The silicon nitride inactivates the virus.

In some aspects, the face mask and/or filter is made of a fibrous material such that droplets or aerosols containing the virus are captured by a mask or filter fibers and the silicon nitride powder inactivates the virus. The virus may be in contact with the silicon nitride powder for at least 1 minute.

Other aspects and iterations of the present invention are described more fully below.

Drawings

FIG. 1 is a schematic representation of influenza A virus.

Fig. 2A is exposure to 0wt.%, 7.5wt.%, 15wt.%, and 30wt.% Si ₃ N ₄ Schematic representation of the virus at 10 min.

FIG. 2B is a graph showing the exposure to Si for the assay according to FIG. 2A ₃ N ₄ Schematic representation of the viability of virus-inoculated cells.

FIG. 3A is exposure to 15wt.% Si ₃ N ₄ Graphical representation of the virus at 1 minute, 5 minutes, 10 minutes, and 30 minutes.

FIG. 3B is a graph for identifying a virus being exposed to Si according to FIG. 3A ₃ N ₄ Schematic representation of the latter method of viability.

Fig. 4A is a graph according to fig. 2A with exposure to 0wt.%, 7.5wt.%, 15wt.% and 30wt.% Si ₃ N ₄ Graph of PFU/100. Mu.l of influenza A at 10 min.

FIG. 4B is a graph according to FIG. 2B with exposure to 7.5wt.%, 15wt.%, and 30wt.% Si ₃ N ₄ Graph of cell viability of influenza a inoculated cells at 10 min.

FIG. 5 contains a graph of the results of using Si that has been exposed to various concentrations ₃ N ₄ Photographs of slurry seeded cells.

Fig. 6A shows fluorescence microscopy images of MDCK cells prior to seeding.

Fig. 6B shows fluorescence microscopy images of MDCK cells after inoculation with control-exposed virus.

FIG. 6C shows a graph with exposure to 30wt.% Si ₃ N ₄ Fluorescent microscopy images of MDCK cells after virus inoculation.

FIG. 7A is exposure to 15wt.% Si at room temperature ₃ N ₄ Plot of PFU/100 μ l for influenza A at 1 min, 5 min, 10 min, or 30 min.

FIG. 7B is a graph showing exposure to 15wt.% Si at room temperature ₃ N ₄ Graph of cell viability of influenza a vaccinated cells at 1 min, 5 min, 10 min or 30 min.

FIG. 8A is an exposure to 15wt.% Si at 4 ℃ ₃ N ₄ Plot of PFU/100 μ l for influenza A at 1 min, 5 min, 10 min, or 30 min.

FIG. 8B is a graph illustrating a graph showing exposure to 15wt.% Si at 4 deg.C ₃ N ₄ Graph of cell viability of influenza a inoculated cells at 1 min, 5 min, 10 min or 30 min.

Fig. 9A shows Raman spectra (Raman spectra) of influenza a virus before inactivation.

Figure 9B shows the raman spectral changes associated with chemical modification of RNA and hemagglutinin of influenza a virus after inactivation after 1 minute of exposure.

FIG. 10 shows NH ₃ Influenza a viruses are inactivated by a basic transesterification mechanism.

FIG. 11 shows O-P-O stretch in a pentacoordinated phosphate group after inactivation.

Fig. 12A shows the vibrational mode of methionine in the hemagglutinin structure.

Fig. 12B shows the structural change of methionine in the presence of ammonia.

FIG. 13 shows the C-S stretch of methionine to homocysteine after inactivation.

FIG. 14A is an exposure to 15wt.% or 30wt.% Si ₃ N ₄ Graphs of PFU/100. Mu.l of Feline calicivirus (Feline calicivirus) at 1 minute, 10 minutes or 30 minutes.

FIG. 14B is a graph with exposure to 30wt.% Si ₃ N ₄ Graph of cell viability of feline calicivirus inoculated cells at 1 minute, 10 minutes, 30 minutes, or 60 minutes.

Fig. 15A shows that H1 influenza a virus (nucleoprotein, NP) was stained red after exposure to a 15wt.% silicon nitride slurry for 10 minutes and green after inoculation into a biogenic medium containing MDCK cells in the presence of filamentous actin (F-actin).

Figure 15B shows NP-stained H1 influenza a virus from figure 15A.

Fig. 15C shows F-actin stained MDCK cells from fig. 15A.

Fig. 16A shows that H1 influenza a virus (nucleoprotein, NP) was stained red without exposure to silicon nitride and green after inoculation into biogenic medium containing MDCK cells in the presence of filamentous actin (F-actin).

Figure 16B shows NP-stained H1 influenza a virus from figure 16A.

Fig. 16C shows F-actin stained MDCK cells from fig. 16A.

Fig. 17 shows a trimodal distribution of silicon nitride powder.

FIG. 18 shows the viability of MDCK cells as beta-Si ₃ N ₄ Concentration (wt.%/mL).

FIG. 19 shows exposure of influenza A to Si ₃ N ₄ Direct comparison of viral titers before and after 30 minutes of powder.

FIG. 20 shows the viability of MDCK cells as alpha-Si ₃ N ₄ Concentration (wt.%/mL).

FIG. 21 shows exposure of influenza A to α -Si ₃ N ₄ Comparison of viral titers before and after 30 minutes of powder.

Figure 22 shows a trimodal particle size distribution of silicon nitride powder.

Figure 23 is an overview of the antiviral test method.

Figure 24A shows Vero cell viability measured 24 hours after exposure to silicon nitride at concentrations of 5, 10, 15 or 20wt.%/vol (n = 4) incubated with cell culture medium for 1, 5 and 10 minutes.

Figure 24B shows Vero cell viability measured 48 hours after exposure to silicon nitride at concentrations of 5, 10, 15, or 20wt.%/vol (n = 4) incubated with cell culture medium for 1, 5, and 10 minutes.

Figure 25A shows titers expressed as PFU/mL of silicon nitride at concentrations of 5, 10, 15, and 20wt.%/vol incubated for 1, 5, and 10 minutes with SARS-CoV-2 virus diluted in cell culture medium.

Figure 25B shows titers expressed as% inhibition of silicon nitride at concentrations of 5, 10, 15, and 20wt.%/vol for 1, 5, and 10 minutes of incubation with SARS-CoV-2 virus diluted in cell culture medium.

Fig. 26A, 26B, 26C and 26D are example antiviral masks.

Fig. 27A, 27B and 27C are example antiviral masks.

FIG. 28A is a cross-section of a body of an example antiviral mask.

FIG. 28B is a cross-section of the body of an example antiviral mask.

Fig. 28C is a cross-section of a body of an example anti-virus mask.

Fig. 29 is an exemplary method of manufacturing a fabric with silicon nitride particles embedded therein.

FIG. 30 is an exemplary system for manufacturing a fabric with silicon nitride particles embedded therein.

Detailed Description

Various embodiments of the disclosure are discussed in detail below. While specific embodiments are discussed, it should be understood that this is done for illustrative purposes only. A person skilled in the relevant art will recognize that other components and configurations may be used without parting from the spirit and scope of the disclosure. The following description and drawings are, accordingly, to be regarded in an illustrative sense and are not to be construed in a limiting sense. Numerous specific details are described to provide a thorough understanding of the present disclosure. However, in certain instances, well-known or conventional details are not described in order to avoid obscuring the description. A reference to one embodiment or an embodiment in this disclosure may be a reference to the same embodiment or any embodiment; also, such references mean at least one of the embodiments.

Several definitions will now be presented that apply throughout this disclosure. Reference to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. In addition, various features are described which may be exhibited by some embodiments and not by others.

As used herein, the terms "comprising", "having" and "including" are used in their open, non-limiting sense. The terms "a" and "an" and "the" are to be understood to cover the plural as well as the singular. Thus, the term "mixture thereof" also relates to "mixture thereof".

As used herein, "about" refers to a numerical value, including integers, fractions, percentages, and the like, whether or not explicitly indicated. The term "about" generally refers to a range of numbers that would be considered equivalent to the recited value (e.g., having the same function or result), e.g., ± 0.5-1%, ± 1-5% or ± 5-10% of the recited value.

As used herein, the term "device" encompasses compositions, devices, surface coatings and/or composites. In some examples, the apparatus may include various medical devices or equipment, examination tables, clothing, filters, masks, gloves, catheters, endoscopic instruments, and the like. The device may be metallic, polymeric, and/or ceramic (e.g., silicon nitride and/or other ceramic materials).

As used herein, the term "silicon nitride" includes Si ₃ N ₄ Alpha-phase or beta-phase Si ₃ N ₄ SiYAlON, siYON, siAlON or combinations of these phases or materials.

As used herein, "inactivation" or "inactivation" refers to viral inactivation in which the virus is prevented from contaminating a product or subject by completely removing the virus or rendering it non-infectious.

As used herein, "personal protective equipment" or "PPE" means any device, article, or apparatus that is worn or otherwise used by an individual to minimize contact with pathogens or other harmful substances. Non-limiting examples of PPE include body covers, headgear, shoe covers, masks, goggles, face and goggles, and gloves.

Within the context of this disclosure and in the specific context in which each term is used, the terms used in this specification generally have their ordinary meaning in the art. Alternative language and synonyms may be used for any one or more of the terms discussed herein, and no special meaning should be implied therefrom regardless of whether a term is detailed or discussed herein. In some cases, synonyms for certain terms are provided. The recitation of one or more synonyms does not exclude the use of other synonyms. The examples used anywhere in this specification (including examples of any terms discussed herein) are illustrative only and are not intended to further limit the scope and meaning of the disclosure or any example terms. As such, the present disclosure is not limited to the various embodiments presented in this specification.

Additional features and advantages of the disclosure will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the principles disclosed herein. The features and advantages of the disclosure may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features of the present disclosure will become more fully apparent from the following description and appended claims, or may be learned by the practice of the principles as set forth herein.

Provided herein are compositions comprising silicon nitride (Si) ₃ N ₄ ) To antipathogenic devices, compositions and apparatus for inactivating viruses, bacteria and fungi. Silicon nitride has a unique surface chemistry that is biocompatible and provides for many biomedical applications, including 1) osteogenesis, osteoinduction, osteoconduction, and bacteriostasis, as are concurrent in spinal and dental implants; 2) Killing both gram-positive and gram-negative bacteria according to different mechanisms; 3) Inactivation of human and animal viruses, bacteria and fungi; and 4) polymers or metal matrix composites, natural or synthetic fibers, polymers or metals containing silicon nitride powders retain the critical silicon nitride bone-healing, bacteriostatic, antiviral and antifungal properties.

In an embodiment, the antipathogenic composition may comprise silicon nitride. For example, the antipathogenic composition may comprise silicon nitride powder. In some embodiments, the antipathogenic composition can be a monolithic component comprising 100% silicon nitride. Such components may be fully dense, having no internal porosity, or porous, having a porosity in the range of about 1% to about 80%. The monolithic assembly may be used as a medical device or may be used in an apparatus where inactivation of viruses, bacteria, and/or fungi may be desired. In another embodiment, an anti-pathogenic composition may be incorporated into the device or coated to inactivate viruses, bacteria, and fungi. In some embodiments, the antipathogenic composition may be a slurry comprising silicon nitride powder.

In some embodiments, the anti-pathogenic composition can inactivate or reduce the spread of human viruses, bacteria, and/or fungi. Non-limiting examples of viruses that can be inactivated by the anti-pathogenic composition include influenza, enterovirus, and coronavirus (e.g., SARS-CoV-2, influenza A, H1N1, enterovirus, and feline calicivirus). For example, silicon nitride bioceramics can effectively inactivate influenza a viruses. In another example, silicon nitride powder may be effective for the inactivation of SARS-CoV-2. In some embodiments, the silicon nitride coating may reduce antibacterial and antiviral resistance and/or promote bone tissue restoration.

Without being bound by a particular theory, silicon nitride may provide a surface chemistry such that ammonia (NH) ₃ ) Can be used for inactivating viruses, bacteria or fungi. The surface chemistry of silicon nitride can be shown as follows:

Si ₃ N ₄ +6H ₂ O→3SiO ₂ +4NH ₃

SiO ₂ +2H ₂ O→Si(OH) ₄

nitrogen elutes faster (within minutes) than silicon because the surface silanol is relatively stable. For viruses, it was surprisingly found that silicon nitride can provide RNA cleavage by basic transesterification, which results in loss of genome integrity and viral inactivation. This may also reduce the activity of hemagglutinin.

In embodiments, the antipathogenic composition may exhibit elution kinetics that show: (i) Ammonia is slowly but continuously washed from the solid state rather than from the normally gaseous state; (ii) has no harm or negative effect on cells; and (iii) the elution increases intelligently as the pH decreases.

The device or apparatus may comprise silicon nitride on at least a portion of the surface of the device for antiviral, antibacterial or antifungal effects. In an embodiment, the device may comprise a silicon nitride coating on at least a portion of a surface of the device. The silicon nitride coating may be applied as a powder to the surface of the device. In some examples, the silicon nitride powder may be embedded or impregnated in at least a portion of the device. In some embodiments, the powder may have particles in the micron, submicron or nanometer size range. The average particle size may range from about 100nm to about 5 μm, from about 300nm to about 1.5 μm, or from about 0.6 μm to about 1.0 μm. In other embodiments, silicon nitride may be incorporated into the device. For example, the device may incorporate silicon nitride powder into the body of the device. In one embodiment, the device may be made of silicon nitride.

The silicon nitride coating may be present on a surface of the device or within the device at a concentration of about 1wt.% to about 100 wt.%. In various embodiments, the coating may comprise about 1wt.%, 2wt.%, 5wt.%, 7.5wt.%, 8.3wt.%, 10wt.%, 15wt.%, 16.7wt.%, 20wt.%, 25wt.%, 30wt.%, 33.3wt.%, 35wt.%, or 40wt.% silicon nitride powder. In at least one example, the coating comprises about 15wt.% silicon nitride. In some embodiments, the silicon nitride may be present in the device or apparatus or on the surface of the device or apparatus at a concentration of about 1wt.% to about 100 wt.%. In various embodiments, the apparatus or device may contain about 1wt.%, 2wt.%, 5wt.%, 7.5wt.%, 8.3wt.%, 10wt.%, 15wt.%, 16.7wt.%, 20wt.%, 25wt.%, 30wt.%, 33.3wt.%, 35wt.%, 40wt.%, 50wt.%, 60wt.%, 70wt.%, 80wt.%, 90wt.% to 100wt.% silicon nitride.

In various embodiments, the device or apparatus comprising silicon nitride for anti-pathogenic properties may be a medical device. Non-limiting examples of devices or apparatuses include orthopedic implants, spinal implants, pedicle screws, dental implants, indwelling catheters, endotracheal tubes, colonoscopes, and other similar devices.

In some embodiments, the silicon nitride may be incorporated into or applied as a coating to materials or devices with anti-pathogenic properties, such as polymers, fabrics, PPE, surgical gowns, tubing, clothing, air and water filters (e.g., filter devices for home, industrial or medical heating, ventilation and air conditioning, anesthesia machines, ventilators or CPAP machines), masks, tables such as hospital examination and operating tables, service tables, fixtures, handles, knobs, toys, or toothbrushes.

In an embodiment, silicon nitride may be incorporated into the PPE to inactivate or prevent the spread of viruses in contact with the PPE. In one embodiment, the PPE is a facemask and embedding silicon nitride into at least a portion of the facemask forms an antiviral facemask that captures and inactivates viruses in contact with the facemask. Without being bound by any one theory, the anti-viral mask may "trap and kill" viruses that come into contact with the silicon nitride within the mask, such that the viruses are not only trapped within the mask, but are also inactivated. The inactivation mechanism of silicon nitride can work rapidly to avoid cross-infection, and the virus can be neutralized in a strain-non-specific manner.

The term "antiviral mask" or "facepiece" as used herein may refer to a surgical facepiece, filtering facepiece, fabric washable facepiece, breathing mask, cup respirator, filtering face piece respirator, elastomeric half-mask respirator, elastomeric full-face respirator, full-face mask, half-mask or full-face mask with a canister, powered air purifying respirator, or any mask that may be worn on the face of a wearer to protect the wearer from potential pathogens. In at least one example, the mask may be a surgical mask. In another example, the mask is a respirator. The antiviral mask may comprise silicon nitride on at least a portion of the mask. In some instances, the antiviral mask may be disposable and intended for a single use. In other examples, the antiviral mask may be reusable such that it may be sterilizable and/or it may utilize a replaceable filter.

Fig. 26A-26D are non-limiting examples of antiviral masks that may include silicon nitride on at least a portion of the mask. Referring to fig. 26A, in some embodiments, the antiviral mask 100 may be a surgical mask. In this embodiment, the antiviral mask 100 may include a mask body 102 and one or more securement mechanisms 108 operable to secure the mask body to a wearer. In some examples, the mask body 102 may include one or more pleats 103 for assisting the mask in fitting the wearer's face. Fig. 26B is an example antiviral mask 100 having a mask body 102 without folds. In some embodiments, the mask body 102 may comprise at least one layer with silicon nitride powder incorporated or embedded within the layer.

In some embodiments, as seen for example in fig. 26C, the antiviral mask 100 may be a cup-type respirator. In this embodiment, the antiviral mask 100 may include a mask body 102, one or more securing mechanisms 108, and a deformable strap 104 on a top portion of the mask body 102 for adjusting the mask 100 over the nose of a wearer. The deformable strip 104 may be attached near the top edge 105 of the mask body 102 on the front surface 106. The transformable band 104 may be made of a material that is easily transformed by the wearer, including but not limited to plastic, spring steel wire wrapped in plastic, or ductile aluminum. In further embodiments, as seen, for example, in fig. 26D, the mask body 102 may further comprise one or more ports/valves 107 or one or more filters 109 for incorporation into a facemask. In one example, the filter 109 may comprise silicon nitride powder incorporated or embedded within the filter. The silicon nitride may be located in a layer or may be uniformly distributed throughout the filter. In some instances, the filter 109 may be disposable and replaceable.

In one embodiment, the antiviral mask 100 may include a disposable, replaceable filter 109. In other embodiments, the mask 100 may contain a bag (not shown) for receiving a disposable filter with silicon nitride powder incorporated or embedded within the filter. In further embodiments, the antiviral mask 100 may be made of washable fabric having a deformable strap 104, one or more securing mechanisms 108 (e.g., adjustable straps), a breather valve 107, and/or a chin guard. The filter may be integral or insertable into each of these mask configurations.

Fig. 27A-27C show further examples of masks that may contain silicon nitride within the mask, a filter inserted into the mask, a canister attached to the mask, and/or a canister attached to the mask. Fig. 27A is an example dual-barrel reusable half-mask that may include silicon nitride in the mask body 102 and/or one or more of the barrels 116. Fig. 27B is an example dual-cartridge reusable full face mask that may include silicon nitride in the mask body 102 and/or one or more of the cartridges 116. Fig. 27C is an example self-contained breathing apparatus that can include silicon nitride in the mask body 102, one or more cartridges 116, and/or one or more canisters 118.

Other non-limiting examples of respirators include a particulate half-respirator that may include silicon nitride in the mask body or filter, a dual-cartridge disposable half-respirator that may include silicon nitride in the mask body and/or in one or more cartridges, a canister respirator that may include silicon nitride in the mask body and/or in one or more canisters, a powered air purifying respirator that may include silicon nitride in the mask body and/or in one or more canisters, a continuous flow supplied air respirator that may include silicon nitride in the mask body and/or in one or more canisters, and a full face mask having two inhalation valves operable to accommodate a filter or cartridge and an exhalation valve.

Referring again to fig. 26A-27C, the mask 100 may be configured to be placed over the nose and mouth of a wearer and may contain one or more securing mechanisms 108 for attaching the mask to the wearer. The securing mechanism 108 may be one or more straps, rings, hooks, bands, or straps for securing the mask to the wearer's face. The securing mechanism 108 may be made of an elastic material or any fibrous material from which the mask body is made. In at least one example, the mask 100 may include two rings 108, each of which is operable to be secured to an ear of a wearer. In another example, the mask 100 may include two straps, each of which is operable to be secured behind the head of the wearer. In further examples, the mask 100 may include a plurality of straps or bands for securing around the head of the wearer. The outer layer 106 of the mask body 102 may contact the wearer's face so that the fibrous material is not in direct contact with the wearer.

The mask body 102 and/or filter 109 can comprise at least one layer, at least two layers, at least three layers, or at least four layers. In some embodiments, one or more layers of the mask body may be made of a fibrous material. The fibrous material may be woven or non-woven and may be air permeable or air impermeable. In some examples, the fibrous material may be a spunbond nonwoven. Non-limiting examples of fibrous materials include polypropylene, rayon, polyester, cellulose, non-oil resistant materials such as KN95, N97, N99, or N100 filters, oil resistant materials such as P95, P97, P99, or P100 filters, and/or semi-oil resistant materials such as R95, R97, R99, or R100 filters. Each layer of the mask body may comprise the same or different fibrous materials. The fibrous material may have silicon nitride embedded therein. In some embodiments, the fibrous material may be removable and/or disposable. For example, in some instances, the layer containing the fibrous material and/or the filter may be removed from the remainder of the mask body and may be discarded after a single use.

Fig. 28A-28C are non-limiting examples of cross-sections of the mask body 102 and/or the filter 109. In one example, as shown in FIG. 28A, the mask body 102 can comprise a fibrous material 111 and an outer layer 112. In this example, the mask body 102 may have an outer layer 112 surrounding the fibrous material 111, with silicon nitride powder incorporated or impregnated into the fibrous material 111 of the mask body 102. Fibrous material 111 may be completely surrounded by outer layer 112 such that outer layer 112 essentially serves as a first layer and a third layer, with fibrous material 111 being a second layer sandwiched between the first layer and the third layer. FIG. 28B is an example cross-section of a mask body 102 having three layers, a fiber material 111 having silicon nitride, a first outer layer 113, and a second outer layer 114. In some examples, the first outer layer 113 and the second outer layer 114 may be made of the same material such that they function similarly to the single outer layer 112 seen in fig. 28A. In other examples, the first outer layer 113 and the second outer layer 114 may be made of different materials. Fig. 28C is an example cross-section of the mask body 102 with four layers, a fiber material 111 with silicon nitride, a second inner layer 115, a first outer layer 113, and a second outer layer 114. In some examples, the first outer layer 113 and the second outer layer 114 may be made of the same material such that they function similarly to the single outer layer 112 seen in fig. 28A. In other examples, the first outer layer 113 and the second outer layer 114 may be made of different materials. The fibrous material may comprise a nonwoven fabric, such as a spunbond fabric. In some examples, fibrous material 111, second inner layer 115, first outer layer 113, second outer layer 114, and/or outer layer 112 may include, but is not limited to, polypropylene, polyester, rayon, nylon, acrylic fiber, N95 filter, zinc, copper, silver, iodine, citric acid, ammonium citrate, or other compounds having antiviral properties. In further examples, second inner layer 115, first outer layer 113, second outer layer 114, and/or outer layer 112 may comprise silicon nitride.

In some examples, the mask body may further include one or more ports or pockets for receiving one or more filters, canisters, or cartridges. In various embodiments, if the mask contains at least one filter, the filter may be layered similarly to the cross-sections in fig. 28A-28C. In some examples, a filter may include silicon nitride within at least a portion of the filter. In other examples, the filter may comprise an N95 filter or a carbon filter. In various instances, the filter may be disposable and replaceable.

In some embodiments, one or more layers and/or one or more filters of the mask body may be coated with a silicon nitride powder. In one example, the fiber material or filter may be coated with silicon nitride. Standard coating methods known in the art may be used to coat the mask body or filter.

In other embodiments, silicon nitride may be embedded, incorporated, or impregnated into a layer, filter, canister, or cartridge of the mask body using methods including, but not limited to, electrospinning, melt spinning, melt blowing, weaving, or ultrasonic impregnation/embedding.

In one embodiment, the silicon nitride may be embedded in a non-woven fabric such as polypropylene using sonication. The resulting silicon nitride embedded fabric can be used to form any PPE. Si may be achieved using a multi-step process ₃ N ₄ Proper surface chemistry, attachment and activation of the particles to the fabric. Fig. 29 is an example manufacturing method 1000 and fig. 30 is an example manufacturing system 200 for embedding silicon nitride into nonwoven spunbond polypropylene fibers.

The nonwoven (i.e., scrim) may need to be pre-cleaned based on packaging, shipping, or storage. The purpose of the pretreatment step is therefore to clean the fabric, improve its wetting properties, and add a coupling agent. First, the fabric 202 is pre-treated to improve cleanliness and wettability. In step 1002, as a first pretreatment step, the fabric 202 is washed in hot deionized water in a first ultrasonic pretreatment tank 204. The configuration of the tank 204 allows the fabric 202 scrim to move continuously through the pretreatment water bath at a distance between about 8 and 10cm above the bottom of the tank under the tension of the roller 216. The ultrasonic transducer 218 may be positioned at the outer bottom of the tank. In some examples, the ultrasonic transducer 218 may be operated with ultrasonic energy ≧ 1000W 25kHz and thermal energy of up to 2000W. The temperature of the pretreatment water bath can be set to be more than or equal to 95 ℃ and less than or equal to 100 ℃. The residence time of the fabric 202 in the bath may be up to about 5, 10, 15, or 20 minutes. For example, if the length of the fabric 202 in the pretreatment tank 204 is about 60cm at any one time, the speed of the fabric 202 through the bath may be 6 cm/min. The purpose of this first pretreatment tank 204 is to remove organic chemicals and loosely attached contaminants. The pretreatment tank 204 operates under a continuous circulation and filtration system to remove contaminants from the water. Upon exiting the pretreatment tank 204, the pressure wringer 220 squeezes excess water out of the fabric 202.

In step 1004, as a second pretreatment step, the fabric is treated with a coupling agent in a second ultrasonic pretreatment tank 206. The second ultrasonic pretreatment tank may contain a water bath with an organic coupling agent. The coupling agent can promote Si ₃ N ₄ The binding of the particles to the fabric. Various examples of coupling agents include quaternary ammonium compounds (bromides), hydroxides, fluorides, or chlorides, which may vary in carbon chain length but have the same or similar functional groups. In one embodiment, the coupling agent is n-Dodecyl Trimethyl Ammonium Bromide (DTAB). In another embodiment, the coupling agent may be dioctadecyldimethylammonium bromide (DODA). The water bath may contain the coupling agent in a weight ratio of about 1. For example, a 1. The ultrasonic transducer 218 may be positioned at the outer bottom of the tank. In some examples, the second ultrasonic pretreatment tank 206 may operate under the same conditions as the first pretreatment tank 204. Since the coupling agent is during this processWill adsorb to the fabric and therefore require a make-up solution. This can be accomplished by a metering system coupled with mechanical agitation within the ultrasonic pretreatment tank 206 itself, or as a separate larger mixing tank connected to the ultrasonic pretreatment tank 206 using a recirculating pumping system (not shown). Upon exiting the second ultrasonic pretreatment tank 206, the pressure wringer 220 squeezes excess water out of the fabric 202, and residual moisture can be removed from the fabric 202 using a heated air blower (not shown) operating at about 100 ℃.

In step 1006, in the presence of water, a dispersant and Si ₃ N ₄ The particles are sonicated in a sonication tank 208 to convert the Si ₃ N ₄ The particles are embedded in the fabric. In one embodiment, the fabric 202 scrim may be continuously fed to a scrim containing waterborne Si ₃ N ₄ In a third ultrasonic tank 208 of the dispersion. Si may be prepared prior to passing fabric 202 through ultrasonic bath 208 ₃ N ₄ A slurry dispersion. The composition of the slurry may comprise Si ₃ N ₄ Powder, dispersant and deionized water. The dispersant may be an ammonium salt of various organic compounds, such as ammonium citrate. The selection and use of dispersants is common to those skilled in the art. In one example, the dispersant may be Dolapix a88. In at least one example, the slurry may include 210g of Si ₃ N ₄ Powder, 2.1g Dolapix A88 dispersant and 790g deionized water. This composition corresponds to about 21wt.% Si ₃ N ₄ And (3) powder. The slurry composition can be adjusted to achieve Si ₃ N ₄ The desired concentration of particles. Typically, the slurry composition may be between about 5wt.% to about 40wt.% Si ₃ N ₄ Within the range of particles. The slurry may be prepared in a separate mixing tank using a high shear (propeller action) mixer, where the Si is pumped using a recirculating pumping system (not shown) ₃ N ₄ The powder, dispersant and water (as needed) are metered into the ultrasonic tank 208. The embedding itself occurs within the ultrasonic bath 208. Similar to the pretreatment, the ultrasonic transducer system 222 is operated with ultrasonic energy of > 1000W 25kHz and up to 2000W of thermal energy and at a temperature of 65 ℃ T75 ℃. The fabric 202 is in the ultrasonic groove 2The residence time in 08 may be about 5, 10, 15 or 20 minutes. Using the previous example, if the length of the fabric 202 in the ultrasonic embedment tank 208 is about 60cm at any one time, the speed of the fabric through the bath may be about 6 cm/min. Upon exiting the ultrasonic tank 208, the pressure wringer 220 squeezes excess stock out of the fabric 202.

In step 1008, the fabric 202 is then dried and thermally bonded with Si in the drying and thermal bonding oven 210 ₃ N ₄ And (3) particles. The thermal bonding oven 210 may be completely enclosed with the fabric inlet 209 and outlet 211 and the heating element 219. Thermal bonding can be accomplished by continuously feeding the fabric 202 into an oven to dry the fabric, and then passing it through a series of smooth-surfaced counter-rotating rollers 217 that simultaneously apply heat and pressure to the fabric (i.e., calendering, as shown in fig. 21). The oven 210 can be operated at 90 ℃. Ltoreq.T.ltoreq.100 ℃ and the calendering rolls 217 can be operated at 140 ℃. Ltoreq.T.ltoreq.145 ℃ with an applied pressure of 500psi ≥ 35 daN/cm. Alternatively, the fabric may be passed directly through preheated calender rolls without entering a drying oven (not shown).

In step 1010, fabric 202 is rinsed in an ultrasonic rinse tank 212 having water and a surfactant to remove excess silicon nitride particles that are not embedded in the fabric. In some embodiments, the washing and rinsing may be performed as two separate steps. In one embodiment, washing and rinsing may be combined in one step. Previous thermal bonding operations may minimize the amount of non-embedded particles. This step may be performed in a continuous ultrasonic bath similar to that used for the pretreatment and intercalation steps. The ultrasonic rinse tank 212 may contain a separate, larger mixing tank and recirculation system (not shown), with a pump as with the other ultrasonic tanks. Within the recirculation system, replaceable cartridge sub-micron filters may be utilized to retain particles released from the fabric. The composition of the rinse solution may comprise a surfactant and water. In some examples, the surfactant may be Triton X-100. The ultrasonic transducer 218 may be positioned at the outer bottom of the tank. Similar to the previous sonication step, the rinsing step 1010 can be conducted at a power level of sonication energy of ≧ 1000W 25kHz, thermal energy of up to 2000W, and a temperature of 60 ≦ T ≦ 70 ℃ in which the residence time of the fabric within the sonication tank is about 5, 10, 15, or 20 minutes. After rinsing, fabric 202 may be passed through wringer 220 to remove excess water.

In step 1012, the rinsed fabric 202 is dried in the drying oven 214. The thermal bonding oven 214 may be completely enclosed with the fabric inlet 213 and outlet 215 and the heating element 219. In some embodiments, the fabric 202 scrim may be fed into a continuous drying oven 214 operating at about 110 ℃ for a residence time of about 5, 10, 15, or 20 minutes. The fabric 202 may then be wound up onto a take-up roll 203.

The slots and/or ovens associated with each step may be operably connected such that a single roll of web 202 may pass through each slot and/or oven throughout the process. The web 202 may be provided as a continuous roll. For example, the web 202 may start at a source roll 201, unwind as it passes through various troughs and ovens, and end at a take-up roll 203. In at least one example, the fabric can be a nonwoven polypropylene spunbond fabric (i.e., a scrim, about 45 g/m) ² ). Polypropylene is hydrophobic in nature (i.e., non-wetting). The fabric may be received as a continuous roll approximately 280mm wide by about 1 km long.

Silicon nitride incorporated into PPE, mask bodies, filters, canisters, cartridges, and the like may be present at a concentration of about 1wt.% to about 30 wt.%. In various examples, the fibrous material may comprise at most about 1wt.%, at most about 2wt.%, at most about 5wt.%, at most about 7.5wt.%, at most about 10wt.%, at most about 15wt.%, at most about 20wt.%, at most about 25wt.%, or at most about 30wt.% silicon nitride powder embedded in the fibrous material. In at least one example, the silicon nitride in the fiber material is present at a concentration of about 1wt.% to about 15wt.% throughout the fiber material. In another example, the silicon nitride in the fibrous material is present at a concentration of less than about 10 wt.%. In various examples, the facemask or one or more filters of the facemask may comprise up to about 1wt.%, up to about 2wt.%, up to about 5wt.%, up to about 7.5wt.%, up to about 10wt.%, up to about 15wt.%, up to about 20wt.%, up to about 25wt.%, or up to about 30wt.% silicon nitride powder. In at least one example, the silicon nitride in the fibrous material is present in a concentration of about 1wt.% to about 15wt.% in at least a portion of the one or more filters in the facepiece. In another example, the silicon nitride in the one or more filters is present at a concentration of less than about 10 wt.%. In some examples, the silicon nitride may be present in a canister or barrel attached to the mask in a concentration of about 1wt.% to about 15wt.%, throughout at least a portion of the canister or barrel. In another example, the silicon nitride in the canister or barrel is present at a concentration of less than about 10 wt.%.

In some embodiments, the organic acid may be further incorporated into a layer of the fibrous material or mask. The acid may be selected from the group consisting of: citric acid, malic acid, tartaric acid, succinic acid, oxalic acid, benzoic acid, isocitric acid, acetic acid, lactic acid, ascorbic acid (e.g., acids commonly found in fruits and vegetables), and combinations thereof. In an embodiment, the acid may be mixed randomly with the silicon nitride powder and embedded in the mask at a concentration in the range of 0.5 to 5.0wt.% of the silicon nitride powder, and preferably in the range of 1.5 to 3.0wt.% and most preferably at about 2.0 wt.%.

The inclusion of one or a combination of these organic acids and their complex mixtures with silicon nitride acidifies the local environment and thereby activates the silicon nitride to release ammonia (NH) ₃ ). Without being bound by theory, during normal breathing of the mask wearer, moisture passes through the mask during exhalation and inhalation. The moisture partially dissolves the organic acid. It dissociates into a base and hydronium ions. Using acetic acid as an example, the reaction is:

the reaction lowers the local pH, thereby creating an acidified environment in the immediate vicinity of the silicon nitride particles. Meanwhile, in the presence of moisture, chemical reactions occur at the silicon nitride surface, releasing ammonia and ammonium, as shown below:

the concentrations of ammonium and ammonia at equilibrium vary with pH. As the pH increases, the amount of ammonium eluted from the silicon nitride decreases. Although the corresponding amount of ammonia eluted increases, its concentration is an order of magnitude lower than that of ammonium. According to Le Chatelier's principal, the release of ammonium tends to raise the local pH, thereby slowing the reaction of silicon nitride with water. The addition of organic acids counteracts this effect. It drives the pH down and reacts with some of the released ammonium. Using acetic acid as an example:

the reaction product consumes ammonium and releases water, which in turn accelerates the reaction with silicon nitride. Thus, the addition of organic acids to the local environment reduces the ammonium concentration, and by doing so, the reaction of silicon nitride with water tends to increase. More ammonium is then released, which also follows the le chatelier principle. This effectively activates the silicon nitride. It reacts with more and more water to form more and more ammonia and ammonium. The release of these moieties is the fundamental mechanism behind the anti-pathogenic effectiveness of silicon nitride. In addition, these organic acids (e.g., citric acid) may themselves exhibit anti-pathogenic properties, regardless of the reaction with silicon nitride described above, but primarily for the purpose of activating the silicon nitride as previously described. Finally, due to its low concentration and edible form, the use of mild organic acids does not create any biocompatibility or health hazard to the mask wearer.

In some embodiments, the layer having silicon nitride may inactivate viruses in contact with the layer of the antiviral mask. For example, droplets or aerosols containing the virus are captured by the mask fibers, and the silicon nitride powder inactivates the virus. Non-limiting examples of viruses that can be inactivated or prevented from transmission through the mask include coronavirus, SARS-CoV-2, influenza A, influenza B, enterovirus, and feline calicivirus. The virus may be contacted with the silicon nitride powder for at least 30 seconds, at least 1 minute, at least 2 minutes, at least 3 minutes, at least 4 minutes, at least 5 minutes, at least 30 minutes, at least 1 hour, or at least 2 hours to be inactivated.

In other embodiments, the silicon nitride powder may be incorporated into a composition including, but not limited to, a slurry, suspension, gel, spray, paint, or toothpaste. For example, adding silicon nitride to a slurry (e.g., paint) and then applying it to a surface can provide an antimicrobial, antifungal and antiviral surface. In other embodiments, the silicon nitride may be mixed with water along with any suitable dispersants and slurry stabilizers and then applied by spraying the slurry onto various surfaces.

In an example, the antipathogenic composition can be a slurry of silicon nitride powder and water. The silicon nitride powder may be present in the slurry at a concentration of about 0.1vol.% to about 20 vol.%. In various embodiments, the slurry may comprise about 0.1vol.%, 0.5vol.%, 1vol.%, 1.5vol.%, 2vol.%, 5vol.%, 10vol.%, 15vol.%, or 20vol.% silicon nitride.

Further provided herein is a method of inactivating a pathogen by contacting a virus, bacteria, and/or fungus with an anti-pathogenic composition comprising silicon nitride. In embodiments, the method may comprise coating the device or apparatus with silicon nitride and contacting the coated apparatus with a virus, bacteria, or fungus. The coating apparatus may comprise applying silicon nitride powder to a surface of the apparatus. In other embodiments, the silicon nitride powder may be incorporated or impregnated within a device or apparatus.

Without being bound by a particular theory, the antipathogenic composition may reduce viral action and decrease the activity of hemagglutinin by basic transesterification. It was surprisingly found that silicon nitride powder (i) significantly reduces the viral action by basic transesterification by breaking the RNA internucleotide bonds and (ii) significantly reduces the hemagglutinin activity, thus disrupting host cell recognition by denaturing the protein structure on the viral surface, leading to viral inactivation, regardless of the presence of the viral envelope.

In embodiments, the antipathogenic composition may exhibit elution kinetics that show: (i) Ammonia is slowly but continuously washed from the solid state rather than from the normally gaseous state; (ii) does not harm or negatively affect the cells; and (iii) the elution increases intelligently as the pH decreases. Furthermore, the inorganic nature of silicon nitride may be more beneficial than the use of petrochemical or organometallic bactericides, virucides and fungicides that are known to harm mammalian cells or have residual effects in soil, plants and vegetables or fruits.

It has surprisingly been found that silicon nitride particles can be electrically attracted and attached to spike proteins on the envelope or membrane of pathogens.

Also provided herein is a method of lysing or inactivating a pathogen at a location in a human patient. For example, the pathogen may be a virus, a bacterium, or a fungus. The method may comprise contacting the patient with an apparatus, device, or composition comprising silicon nitride. Without being bound by any one theory, silicon nitride inactivates pathogens. The device, apparatus, or composition may comprise from about 1wt.% to about 100wt.% silicon nitride. In some examples, the device or apparatus may comprise about 1wt.% to about 100wt.% silicon nitride on the surface of the device or apparatus. In an embodiment, the apparatus or device may be a monolithic silicon nitride ceramic. In another embodiment, the apparatus or device may comprise a silicon nitride coating, such as a silicon nitride powder coating. In another embodiment, a device or apparatus may incorporate silicon nitride into the body of the device. For example, silicon nitride powder may be incorporated or impregnated into the body of a device or apparatus using methods known in the art.

In some embodiments, the device or apparatus may be in contact with the patient or user for at least 1 minute, at least 5 minutes, at least 30 minutes, at least 1 hour, at least 2 hours, at least 5 hours, or at least 1 day. In at least one example, the device or apparatus may be permanently implanted in the patient. In at least one example, the apparatus or device may be worn externally by the user.

Examples of the invention

Example 1: effect of silicon nitride concentration on Virus inactivation

To show the effect of silicon nitride concentration on inactivation of virus, influenza a was exposed to various concentrations of Si ₃ N ₄ And (3) powder. For preparing silicon nitride, a certain weight is addedAn amount of silicon nitride powder was mixed with pure distilled water. For example, 7.5g of silicon nitride was dispersed in 92.5g of pure distilled water. Viruses were added to this mixture at concentrations of 1. These mixtures were then incubated at 4 ℃ for 10 minutes with gentle stirring. Influenza a was exposed to 0wt.%, 7.5wt.%, 15wt.% and 30wt.% Si at 4 ℃ ₃ N ₄ 10 minutes, as shown in fig. 2A. The mixture was then filtered to remove the silicon nitride powder.

Then for Si ₃ N ₄ Effectiveness in inactivating influenza A Martin-Darby Canine Kidney (MDCK) cells inoculated with influenza A virus were observed. The remaining mixture was then seeded into Petri dishes containing live MDCK cells in a culture medium of biological origin. The number of viable MDCK cells was then counted after 3 days of exposure using a staining method. According to FIG. 2B, with exposure to Si ₃ N ₄ The activity of MDCK cells was measured 3 days after inoculation of influenza a virus.

Fig. 4A is exposure to 0wt.%, 7.5wt.%, 15wt.%, and 30wt.% Si ₃ N ₄ Graph of PFU/100. Mu.l of influenza A at 10 min. FIG. 4B is a graph with exposure to 7.5wt.%, 15wt.%, and 30wt.% Si ₃ N ₄ Graph of cell viability of influenza a inoculated cells for 10 min.

Example 2: effect of Exposure time and temperature on Virus inactivation

To show the effect of silicon nitride on inactivation of virus, influenza a was exposed to fixed concentrations of Si at various times and temperatures ₃ N ₄ Powder (15 wt.%). The mixture was then incubated at room temperature and 4 ℃ for 1 to 30 minutes with gentle stirring. For example, influenza a is exposed to 15wt.% Si at room temperature or 4 ℃ ₃ N ₄ 1 minute, 5 minutes, 10 minutes, or 30 minutes, as illustrated in fig. 3A. Then for Si ₃ N ₄ Effectiveness in inactivating influenza a mardin-darby dog kidney (MDCK) cells inoculated with influenza a virus were observed. According to FIG. 3B, with exposure to Si ₃ N ₄ Influenza A virus of (A) inoculated MDCK cells 3After day, the viability of the cells was determined.

FIG. 7A is exposure to 15wt.% Si at room temperature ₃ N ₄ Plot of PFU/100 μ l for influenza A at 1 min, 5 min, 10 min, or 30 min. FIG. 7B is a graph with exposure to 15wt.% Si at room temperature ₃ N ₄ Graph of cell viability of influenza a inoculated MDCK cells at 1, 5, 10 or 30 minutes.

FIG. 8A is an exposure to 15wt.% Si at 4 ℃ ₃ N ₄ Plot of PFU/100 μ l for influenza A at 1 min, 5 min, 10 min or 30 min. FIG. 8B is a graph of Si with 15wt.% exposure to Si at 4 deg.C ₃ N ₄ Graph of the survival of influenza a vaccinated MDCK cells at 1 min, 5 min, 10 min or 30 min.

Example 3: effect of silicon nitride on inactivation of H1H1 influenza A

To show the effect of silicon nitride on inactivation of virus, influenza a was exposed to a slurry of 15wt.% silicon nitride for 10 minutes.

Fig. 15A-15C show that H1 influenza a virus (a/puerto rico/8/1934H 1N1 (PR 8)) was stained red (nucleoprotein, NP) after inoculation into a biologically derived medium containing MDCK cells stained green in the presence of filamentous actin (F-actin), which is present in all eukaryotic cells. Fig. 16A-16C show the effect of the virus on MDCK cells in the absence of silicon nitride.

Example 4: evaluation of silicon nitride for virucidal Activity against influenza A Virus in MDCK cells

This study was designed to examine beta-silicon nitride (beta-Si) at an incubation time point of 30 minutes and a concentration of 15wt.%/vol ₃ N ₄ ) Antiviral ability of the powder against influenza a virus. A 15wt.% suspension was prepared in 1.5mL of virus diluted in DMEM without any additives.

The plaque assay method was used. For adequate quantification of plaque assays, the viability of Madin-Darby Canine Kidney cells (MDCK) was assessed as exposure to varying concentrations of Si ₃ N ₄ The duration of 30 minutes to 72 hours of incubation period function was evaluated. As a result, theProve that, under preselected conditions, si ₃ N ₄ Is completely virucidal against influenza A virus in which the viral load is reduced>99.98 percent. The viability of MDCK cells was found to be time and dose dependent. For Si up to 15wt.%/vol ₃ N ₄ At concentrations where essentially no loss of viability was observed. Only the viability changes at the 15wt.% concentration at 24, 48 and 72 hours (i.e., 83.3%, 59.7% and 44.0% viability, respectively) were noted.

Si used in this study ₃ N ₄ The nominal composition of the powder is 90wt.% alpha-Si ₃ N ₄ 6wt.% yttria (Y) ₂ O ₃ ) And 4wt.% alumina (Al) ₂ O ₃ ). It is prepared by water mixing and spray drying of inorganic components, followed by sintering of the spray dried granules (about 1700 ℃ for about 3 hours), hot isostatic pressing (in N) ₂ Medium about 1600 ℃,2 hours, 140 MPa), water-based milling and freeze-drying. The resulting powder had a trimodal distribution with an average particle size of 0.8. + -. 1.0. Mu.m, as shown in FIG. 17. With Y ₂ O ₃ And Al ₂ O ₃ Doping of Si ₃ N ₄ Helping to densify the ceramic and transform it from the alpha phase to the beta phase in the sintered device. The mechanism of densification is by dissolution of the alpha phase and subsequent precipitation of beta phase grains, facilitated by the formation of transient intercrystalline liquids that solidify in the cooling device. Thus, beta-Si ₃ N ₄ Is composed of about 10wt.% intergranular vitreous phase (IGP) and 90wt.% crystalline beta-Si ₃ N ₄ A composite material composed of crystal grains.

Three consecutive assays were performed in this study: (1) MDCK viability test; (2) Influenza a supernatant titration test with and without centrifugation and filtration; (3) Use 15wt.%/vol Si ₃ N ₄ The virus was titrated as a viral inhibitor with a latency of 30 minutes.

In FIG. 18, the viability of MDCK cells is shown as beta-Si ₃ N ₄ Concentration (wt.%/mL). Starting from 15wt.%, serial dilutions were made to reach 0.047wt.%. At lower concentrations, cell viability was typical up to all time points of 72 hours>80 percent. It should also be noted that forAt all concentrations other than 15wt.%, cell viability generally increases with exposure time. At 15wt.% and 30 min exposure, the cell viability was about 94.5%.

After determining MDCK cell viability, twenty-four hours before adding virus and sample to cells, MDCK cells were plated in 6-well plates at 1 × 10 ⁶ Density of individual cells/well was plated in 2mL volume of du shi minimal essential medium (DMEM) supplemented with 10% Fetal Bovine Serum (FBS). On the day of measurement, a silicon nitride film containing 15wt.% of silicon nitride was measured at 1X 10 ⁴ Triplicate samples of PFU/mL virus diluted in DMEM without additives were incubated at room temperature for 30 minutes with shaking. After incubation, the samples were centrifuged at 4 ℃ and 12,000rpm for two minutes and further filtered through a 0.2 micron polyvinylidene fluoride (PVDF) filter. The samples were then serially diluted as 1. The samples were incubated at 37 ℃ for 1 hour with shaking every 15 to 20 minutes. After incubation, 2mL plaque assay medium was added to the wells and the culture was incubated at 35 ℃/5% CO ₂ The cells were incubated for 48 hours. After incubation, cells were stained with crystal violet and plaques were visually counted.

On the day of staining, the disturbing medium was removed and the monolayer cells were washed twice with DPBS. Cells were then fixed with 70% ethanol for 10 min at room temperature. The ethanol was removed and a 0.3% crystal violet solution was added to each well for 10 minutes at room temperature. After incubation, the crystal violet was removed and the monolayer washed twice with DPBS to remove residual crystal violet. The single layer was air dried overnight before plaque counting.

Virucidal testing was performed at a concentration of 15wt.%/vol and at 30 minutes. The process steps of centrifugation and filtration only reduced the viral load by about 0.25log ₁₀ . In view of this result, the virus was then exposed to Si without ₃ N ₄ The subsequent titration was carried out for 30 minutes. Based on ISO 21702 (antiviral activity measurement on plastics and other nonporous surfaces), without Si ₃ N ₄ The titre of (A) is selected a priori to be 4.4X 10 ³ pfu/ml。On exposure to Si ₃ N ₄ After a duration of 30 minutes, no plaques were formed on MDCK cells. Si ₃ N ₄ Is considered to be 100% effective in inactivating influenza a virus. In FIG. 19, the pairs are provided in exposure to Si ₃ N ₄ The powder was held for a direct comparison of the virus titer before and after 30 minutes. The data clearly demonstrate exposure to Si ₃ N ₄ Subsequent viral load reduction>3.5log ₁₀ (i.e., the ratio of,>99.98％)。

in summary, these tests demonstrate that Si is added at concentrations below 15wt.%/vol or at times ≦ 30 minutes ₃ N ₄ Exposure to MDCK cells had no adverse viability effects. At 15wt.%/vol Si ₃ N ₄ Under the antiviral test conditions of (1), at 4.4X 10 ³ Exposure to pfu/ml viral load for 30 min, si ₃ N ₄ Substantially inactivating 100% of the exposed virus particles. Under these conditions, si was found ₃ N ₄ Is virucidal against influenza a viruses.

Example 5: alpha-Si ₃ N ₄ Effect of powder on MDCK cells and influenza A

After 30 minutes, 24 hours, 48 hours and 72 hours of exposure, the alpha-Si was first evaluated ₃ N ₄ Toxicity of the powder to MDCK cells. A 15wt.% (wt.%) suspension was prepared in 1.5mL of Dule's Modified Eagle's Medium (DMEM) supplemented with 2% Fetal Bovine Serum (FBS).

Twenty-four hours before adding the sample to the cells, the α -Si prepared as described above was added ₃ N ₄ The powder suspension was incubated at room temperature for 30 minutes with shaking. After incubation, the suspension was centrifuged at 12,000rpm for two minutes at 4 ℃. The supernatant was further filtered through a 0.2 micron polyvinylidene fluoride (PVDF) filter and then serially diluted in 1/2 log increments. Six (6) concentrations were added to the pre-plated cells in triplicate in volumes of 200 μ L. The plates were incubated for 30 min, 24, 48 and 72 h, at which time the tetrazolium dye XTT (2, 3-bis (2-methoxy-4-nitro-5-sulfophenyl) -5- [ (phenylamino) carbonyl was used]-2H-tetrazole hydroxide) to assess cellular cytotoxicity, as described below.

The TC50 value of the test material is obtained by measuring the degree of reduction of the tetrazolium dye XTT. XTT in metabolically active cells is metabolized by the mitochondrial enzyme NADPH oxidase to soluble formazan products. XTT solution was prepared as 1mg/mL stock solution daily in DMEM without additives. A solution of Phenazine Methosulfate (PMS) was prepared in Duchen Phosphate Buffered Saline (DPBS) at a concentration of 0.15mg/mL and stored in the dark at-20 ℃. XTT/PMS stock was prepared immediately before use, adding 40 μ L of PMS per mL of XTT solution. Fifty μ L (50) of XTT/PMS was added to each well of the plate and the plate was incubated at 37 ℃ for 4 hours. It was empirically determined that the 4 hour incubation was within the linear response range of XTT dye reduction, where the number of cells per assay was specified. The plates were sealed and inverted several times to mix the soluble formazan product and read at 450nm (650 nm reference wavelength) using a molecular apparatus SpectraMax Plus 384 96 well plate spectrophotometer.

MDCK cells were treated with 6 concentrations of α -Si ranging from 15wt.% to 0.047wt.% ₃ N ₄ The powder treatment lasted 30 minutes, 24 hours, 48 hours and 72 hours. In FIG. 20, the viability of MDCK cells is shown as α -Si ₃ N ₄ Concentration (wt.%/mL). After 30 minutes of exposure, the viability of cells treated with all concentrations was greater than 90%, but cells treated with 4.7wt.% and 15wt.% had 89% and 83% viability, respectively. The viability of the cells treated with each concentration at 24 hours was still higher than 92%. In cells treated with 1.5wt.%, 4.7wt.%, and 15wt.%, viability decreased to below 90% (89.1%, 88.7%, and 74.0%, respectively) at 48 hours, but only 15wt.% of cells treated at 72 hours had viability below 90% (87.5%).

Then 15wt.% of alpha-Si was evaluated ₃ N ₄ Virucidal activity of the powder against influenza A virus strain A/PR/8/34 in MDCK cells. A 15wt.% suspension was prepared in 1.5mL of virus diluted in DMEM without any additives.

Twenty-four hours before adding virus and sample to cells, MDCK cells were plated in 6-well plates at 1 × 10 ⁶ Individual cell/well density plated in 2mL volume supplementIn Duchen Minimal Essential Medium (DMEM) with 10% Fetal Bovine Serum (FBS). On the day of measurement, will contain 15wt.% of α -Si ₃ N ₄ At 1 × 10 ⁴ Triplicate samples of PFU/mL virus diluted in DMEM without additives were incubated at room temperature for 30 minutes with shaking. After incubation, the samples were centrifuged at 4 ℃ and 12,000rpm for two minutes and further filtered through a 0.2 micron polyvinylidene fluoride (PVDF) filter. The samples were then serially diluted as 1. The samples were incubated at 37 ℃ for 1 hour with shaking every 15 to 20 minutes. After incubation, 2mL plaque assay medium was added to the wells and the culture was incubated at 35 ℃/5% CO ₂ The cells were incubated for 48 hours. After incubation, cells were stained with crystal violet and plaques were visually counted.

On the day of staining, the spotting medium was removed and the monolayer cells were washed twice with DPBS. Cells were then fixed with 70% ethanol for 10 min at room temperature. The ethanol was removed and a 0.3% crystal violet solution was added to each well for 10 minutes at room temperature. After incubation, the crystal violet was removed and the monolayer washed twice with DPBS to remove residual crystal violet. The monolayer was air dried overnight before counting plaques.

15wt.% alpha-Si was evaluated ₃ N ₄ Virucidal activity of the powder against influenza A virus strain A/PR8/34 in MDCK cells. The target virus titer was 1X 10 ⁴ PFU/mL, and the actual individual replica is 3.1X 10 ³ 、3.8×10 ³ And 4.7X 10 ³ PFU/mL, produced a mean titer (and standard deviation) of 3.9X 10 ³ ±0.8×10 ³ PFU/mL. This actual titer is within two-fold of the target PFU/mL. Via alpha-Si ₃ N ₄ The powder treated sample had one well with a single plaque, resulting in a PFU/mL of 4.1.

The log reduction was 2.98 and was calculated using the following equation: log (log) ₁₀ (A/B), wherein A is an untreated virus and B is a treated virus. The percent reduction was 99.89% and was calculated using the following equation: (A-B) x 100/A, wherein AIs untreated virus and B is treated virus. FIG. 21 provides a graph showing the results of exposure to α -Si ₃ N ₄ Comparison of viral titers before and after 30 minutes of powder. Thus, 15wt.% of α -Si ₃ N ₄ The powder was virucidal against influenza A virus strain A/PR/8/34 after 30 minutes exposure.

Example 6: two forms of Si ₃ N ₄ Virucidal Activity of powders against influenza A Virus in MDCK cells

5 and 10wt.% of α -Si was prepared in 1.5mL of virus diluted in DMEM without any additives ₃ N ₄ And beta-Si ₃ N ₄ A powder suspension.

Twenty-four hours before adding virus and sample to cells, MDCK cells were plated at 1 × 10 in 6-well plates ⁶ Density of individual cells/well was plated in 2mL volume of du shi minimal essential medium (DMEM) supplemented with 10% Fetal Bovine Serum (FBS). On the day of determination, 10 and 5wt.% of α -Si will be contained ₃ N ₄ And beta-Si ₃ N ₄ Powder of 1X 10 ⁴ Triplicate samples of PFU/mL virus diluted in DMEM without additives were incubated at room temperature for 30 minutes with shaking. After incubation, the samples were centrifuged at 4 ℃ and 12,000rpm for two minutes and further filtered through a 0.2 micron polyvinylidene fluoride (PVDF) filter. The samples were then serially diluted as 1. The samples were incubated at 37 ℃ for 1 hour with shaking every 15 to 20 minutes. After incubation, 2mL plaque assay medium was added to the wells and the culture was incubated at 35 ℃/5% CO ₂ The cells were incubated for 48 hours. After incubation, cells were stained with crystal violet and plaques were visually counted.

On the day of staining, the disturbing medium was removed and the monolayer cells were washed twice with DPBS. The cells were then fixed with 70% ethanol for 10 min at room temperature. The ethanol was removed and a 0.3% crystal violet solution was added to each well for 10 minutes at room temperature. After incubation, the crystal violet was removed and the monolayer was washed twice with DPBS to remove residual crystal violet. The monolayer was air dried overnight before counting plaques.

5 and 10wt.% of alpha-Si was evaluated ₃ N ₄ And beta-Si ₃ N ₄ Virucidal activity of the powder against influenza A virus strain AIPR8/34 in MDCK cells. This was done in four separate experiments. The target virus titer is 1 × 10 ⁴ PFU/mL。

In the first experiment, the individual replicates of the untreated virus sample were 5.3X 10 ³ 、5.9×10 ³ And 4.1X 10 ³ PFU/mL, produced a mean titer (and standard deviation) of 5.1X 10 ³ ±0.9×10 ³ PFU/mL. With 5wt.% and 10wt.% beta-Si ₃ N ₄ Treatment of 10 minutes of virus resulted in PFU/mL of virus treated with 10wt.%<21 and PFU/mL of virus treated with 5wt.% was 21 (formation of 1 plaque). In this sample, the log reduction was 2.4 and was calculated using the following equation: log10 (NB), where a is untreated virus and B is treated virus. The percent reduction was 99.5% and was calculated using the following equation: (A-B) x 100/A, wherein A is untreated virus and B is treated virus.

In a second experiment, the individual replicates of the untreated virus sample were 7.5X 10 ³ 、7.2×10 ³ And 5.0X 10 ³ PFU/mL, yielded a mean titer (and standard deviation) of 6.6X 10 ³ ±1.4×10 ³ PFU/mL. With 5wt.% and 10wt.% beta-Si ₃ N ₄ PFU/mL of both virus production treated for 5 min<21。

In the third experiment, the individual repeat was 6.9X 10 ³ 、7.8×10 ³ And 5.0X 10 ³ PFU/mL, yielded a mean titer (and standard deviation) of 6.6X 10 ³ ±1.4×10 ³ PFU/mL. With 5wt.% and 10wt.% of alpha-Si ₃ N ₄ PFU/mL of both virus-produced treated for 10 min<21。

In the fourth experiment, the individual repeat was 8.8X 10 ³ 、1.0×10 ⁴ And 7.5X 10 ³ PFU/mL, produced a mean titer (and standard deviation) of 8.8X 10 ³ ±1.3×10 ³ PFU/mL. With 5wt.% and 10wt.% of alpha-Si ₃ N ₄ PFU/mL of both virus production treated for 5 min<21。

In each experiment, the actual titer determined for the untreated virus control was within two-fold of the target PFU/mL. With 5 and 10wt.% of alpha-Si ₃ N ₄ And beta-Si ₃ N ₄ Both powder treatment of virus for 5 min and 10 min resulted in PFU/mL<1 (no plaque observed), but via beta-Si ₃ N ₄ The powder treated sample had one well with a single plaque, except at 5wt.% for 10 minutes, resulting in a PFU/mL of 21.

Example 7: in vitro inactivation of SARS-CoV-2 by silicon nitride

Preparation of alpha-Si with a nominal composition of 90wt.% by water mixing and spray drying of the inorganic ingredients ₃ N ₄ 6wt.% yttria (Y) ₂ O ₃ ) And 4wt.% alumina (Al) ₂ O ₃ ) Doped Si of ₃ N ₄ Powder (. Beta. -SiYAlON), then sintering the spray-dried particles (about 1700 ℃ C., about 3 hours), hot isostatic pressing (in N) ₂ Medium temperature about 1600 ℃,2 hours, 140 MPa), water-based milling and freeze-drying. The resulting powder had a trimodal distribution with an average particle size of 0.8. + -. 1.0. Mu.m, as shown in FIG. 22. By Y ₂ O ₃ And Al ₂ O ₃ Doping of Si ₃ N ₄ The ceramic is densified and transformed from the alpha phase to the beta phase in the sintered device. The mechanism of densification is by dissolution of the alpha phase and subsequent precipitation of beta phase grains, facilitated by the formation of transient intercrystalline liquids that solidify in the cooling device. Thus, beta-Si ₃ N ₄ Is composed of about 10wt.% intergranular vitreous phase (IGP) and 90wt.% crystalline beta-Si ₃ N ₄ A composite material composed of crystal grains.

Vero green African monkey kidney epithelial cells were chosen for this assay because of their ability to support high levels of SARS-CoV-2 replication and their use in antiviral assays. These cells were cultured in DMEM supplemented with 10% FBS, 1% L-glutamine and 1% penicillin/streptomycin. Cells were maintained at 37 ℃ and 5% CO ₂ The following steps. SARS-CoV-2 isolate USA-WA1/2020 from BEI Resources corporation. Vero cells were inoculated with SARS-CoV-2 (MOI 0.1) to produce a virus stock. Cell-free supernatants were collected 72 hours post infection and clarified by centrifugation at 10,000rpm for 10 minutes and filtered through a 0.2 μm filter. Stock virus was titrated according to the plaque assay protocol detailed below.

Mixing Si ₃ N ₄ The powder was suspended in 1mL DMEM growth medium in a microcentrifuge tube. The tubes were vortexed for 30 seconds to ensure adequate contact, and then placed on a tube spin mixer for 1 minute, 5 minutes, or 10 minutes. At each time point, the samples were centrifuged and the supernatant was collected and filtered through a 0.2 μm filter. The clarified supernatant was added to the cells for 24 or 48 hours. Untreated cells were maintained aside as controls. Cells were tested at each time point using CellTiter Glo, which measures ATP production, to determine cell viability.

SARS-CoV-2 was diluted to 2X 10 in DMEM growth medium ⁴ Concentration of PFU/mL. Four mL of diluted virus was added to tubes containing 20, 15, 10 and 5% (w/v) silicon nitride. Parallel treatment without Si ₃ N ₄ As a control. The tubes were vortexed for 30 seconds to ensure adequate contact, and then placed on a tube spin mixer for 1 minute, 5 minutes, or 10 minutes, while the virus-only control was incubated for up to 10 minutes. At each time point, the samples were centrifuged and the supernatant was collected and filtered through a 0.2 μm filter. The remaining infectious virus in the clarified supernatant was quantified by plaque assay. Figure 23 provides an overview of the antiviral test method. In step 1, SARS-CoV-2 virus is diluted in culture medium. In step 2, 4mL of diluted virus was added to a tube containing 20%, 15%, 10% or 5% (w/v) silicon nitride. In step 3, the tubes were vortexed for 30 seconds to ensure adequate contact, and then placed on a tube spin mixer for 1 minute, 5 minutes, or 10 minutes (virus-only controls were incubated for up to 10 minutes). In step 4, at each time point, the samples were centrifuged and the supernatant was collected and filtered through a 0.2 μm filter. In step 5, the clarified supernatant is subjected toThe solution was used to perform plaque assay. Samples were serially diluted (10 fold) and added to fresh Vero for 1 hour incubation, shaken every 15 minutes, then agarose media overlays were added and incubated for 48 hours. After 48 hours of incubation, cells were fixed with 10% FA and stained with crystal violet for counting.

One day before plaque assay, vero cells were plated at 2X 10 ⁵ Individual cells/well were seeded in 12-well plates. Clear supernatants from the anti-virus assay were serially diluted (10-fold) and 200 μ L was added to Vero cells at 37 ℃, 5% CO ₂ The mixture was incubated for 1 hour. Plates were shaken every 15 minutes to ensure adequate coverage, and 0.6% agarose and 2 xemes supplemented with 5% FBS, 2% penicillin/streptomycin, 1% nonessential amino acids (VWR, catalog number 45000-700), 1% sodium pyruvate, and 1% L-glutamine were added to cells at 1 hour at a ratio of 1 ₂ The cells were incubated for 48 hours. After incubation, cells were fixed with 10% formaldehyde and stained with 2% crystal violet in 20% ethanol for counting.

Test Si ₃ N ₄ Influence on the viability of eukaryotic cells. Si ₃ N ₄ Resuspended in cell culture media at 5, 10, 15 and 20% (w/v). Samples were collected at 1, 5 and 10 minutes and added to Vero cells. Vero cell viability was measured at 24 and 48 hours post-exposure (fig. 24A and 24B). No significant decrease in cell viability was observed at 24 or 48 hours after exposure to 5%, 10% or 15% silicon nitride. After exposure to 20% Si ₃ N ₄ Of the cells of (4), a small effect on cell viability was observed at 48 hours (about 10% decrease). Interestingly, about 10% increase in Vero cell viability was observed at 48 hours in the 5% -10 min and 10% -10 min samples (FIG. 24B), indicating that Si ₃ N ₄ It is possible to stimulate cell growth or cell metabolism under these conditions. These data show that Si is present ₃ N ₄ The impact on Vero cell health and viability was minimal and at most 20wt.%/vol.

Considering 5, 10, 15 and 20% Si ₃ N ₄ It is not toxic to Vero cells and therefore antiviral tests were performed at these concentrations. SARS-CExposure of oV-2 virions to Si at these concentrations ₃ N ₄ For 1, 5 or 10 minutes. In Si ₃ N ₄ After exposure, residual infectious virus in each solution was determined by plaque assay. At each time point, the samples were centrifuged and the supernatant was collected and filtered through a 0.2um filter. The clarified supernatant was used for plaque assays in duplicate. Parallel processing but only exposure to a solution containing 4.2X 10 ³ PFU/mL of cell culture medium. When exposed to all concentrations of Si ₃ N ₄ When tested, the SARS-CoV-2 titer was reduced (FIGS. 25A and 25B). SARS-CoV-2 exposure continued for 1 min and 5% Si ₃ N ₄ About 0.8log reduction in viral titer ₁₀ 、10％ Si ₃ N ₄ Reduction of about 1.2log ₁₀ 、15％ Si ₃ N ₄ Reduction of 1.4log ₁₀ And 20% Si ₃ N ₄ 1.7log reduction ₁₀ Inhibition was dose dependent (fig. 25A). Similar results were observed with 5 min and 10 min samples. This reduction in viral titer corresponds to 5% Si ₃ N ₄ 85% viral inhibition, 10% Si ₃ N ₄ At the time of 93%, 15% Si ₃ N ₄ At a time of 96% and 20% Si ₃ N ₄ At 98% viral inhibition (fig. 25B). Higher Si for longer periods ₃ N ₄ The concentration will increase the inhibition-produced at 20% Si ₃ N ₄ And 99.6% viral inhibition at 10 min exposure (fig. 25B). These data show that Si is present ₃ N ₄ Has strong antiviral effect on SARS-CoV-2.

It was surprisingly found that at 5% Si ₃ N ₄ One minute exposure to the solution resulted in inactivation of 85% of SARS-CoV-2, while Vero cell viability was barely affected even after 48 hours exposure to the same material at 20% concentration.

Example 8: embedding silicon nitride in a fabric

Pretreatment of

The pretreatment is carried out in two successive steps. In a first step, the scrim section is pre-cleaned by stirring for 10 minutes in a covered heated tank containing deionized water (90 ℃ C. ≦ T ≦ 100 ℃ C.). After cleaning, the scrim was air dried. This step tends to remove the organic chemicals used in the manufacture of the fabric as well as loosely attached contaminants due to shipping and storage. Detergents are avoided to prevent interference with the coupling agent. In the second step, the fabric was immersed in a room temperature water bath with stirring. Due to its hydrophobicity, the scrim must be held underwater. This was done by placing the fabric in a covered 304 stainless steel basket. An organic surfactant (i.e., a coupling agent) is added to the bath. The surfactant used was n-Dodecyl Trimethyl Ammonium Bromide (DTAB). The amount of DTAB added was calculated based on the weight of the scrim to be treated using: DTAB weight (g) = scrim weight (g) × 1.73. After addition of DTAB, the bath temperature was increased to 100 ℃ (boiling) and held at this temperature for 30 minutes. The scrim was then removed from the bath and laid flat in a 110 ℃ circulating air oven for 10 minutes to dry.

Embedding process

The embedding process takes three process steps. The first step involves the preparation of Si ₃ N ₄ Dispersion of the powder in deionized water. This is done by weighing and mixing water, organic dispersant and Si ₃ N ₄ Discharging into a vibratory or ball mill and agitating the ingredients for at least 30 minutes. The dispersion can also be achieved using a high intensity shear mixer (i.e., propeller action) for about the same length of time. The composition of the dispersion was as follows (based on about 1 liter batch size): 210.0g Si ₃ N ₄ Powder, 2.1g of Dolapix A88 dispersant and 790.0g of deionized water.

The second step involves reacting Si ₃ N ₄ The dispersion (i.e., slurry) was siphoned into a handheld HTE compatible spray gun and at a pressure of about 30psi (2.1 bar, 210kpa) and about 0.45ml/cm ² Is applied evenly to one side of the pretreated fabric by hand at a distance of about 0.5 meters. After air drying for about 10 minutes, the opposite side of the scrim was then coated in the same manner. The spray process was then repeated a second time (i.e., two applications per side). The third step involves a temperature of 65 ℃ T75 ℃ and about 60W and 20kHz, power setting, the coated scrim was immersed in residual Si in a Branson lab ultrasonic bath ₃ N ₄ The slurry was held for 10 minutes. Thereafter, the fabric was placed into a wringer to remove excess slurry and then placed flat in a drying oven at about 110 ℃ for about 10 minutes.

Thermal bonding

Si ₃ N ₄ The adhesion of the particles to the scrim was achieved by placing a single fabric between two precision heavy duty stainless steel plates in an oven at 145 ℃ for 90 minutes. The process generates a pressure on the fabric of about 0.1psi (about 0.7 kPa). This pressure is used to force the Si ₃ N ₄ It is important that the particles are embedded in the polypropylene fibers. The panel containing the fabric was then removed from the oven and allowed to cool to room temperature.

Washing and rinsing

Rinsing is an important step. Rinsing removed unbound Si from the fabric ₃ N ₄ And (3) granules. This is accomplished in a two-step operation. The first step involved washing the embedded scrim in deionized water using a nonionic surfactant in a Branson lab ultrasonic bath operating at a power setting of about 60W and 20 kHz. The composition of this washing step was as follows (based on 1 liter batch size): 10.0g Triton X-100 surfactant and 990.0g deionized water.

After the preparation of the washing bath, the fabric is immersed in water and sonicated at 60 ℃ T < 70 ℃ for five minutes. The scrim is then pulled through a wringer to remove excess liquid. The second step involved rinsing the scrim in clean deionized water. This was also done in an ultrasonic bath at a temperature of 60 ℃ T70 ℃ with power settings of about 60W and 20kHz for five minutes. Repeated rinse cycles are often performed until the rinse water is clear.

Drying the mixture

The cleaned and rinsed fabric was dried by simply laying it flat on a drying cabinet rack at about 110 c for about 10 minutes.

While several embodiments have been described, it will be appreciated by those of ordinary skill in the art that various modifications, alternative constructions, and equivalents may be used without departing from the spirit of the invention. In addition, many well known processes and elements have not been described in order to avoid unnecessarily obscuring the present invention. Accordingly, the above description should not be taken as limiting the scope of the invention.

Those skilled in the art will appreciate that the presently disclosed embodiments are taught by way of example and not limitation. It is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. The following claims are intended to cover all generic and specific features described herein, as well as all statements of the scope of the present method and system, which, as a matter of language, might be said to fall therebetween.

Claims (20)

1. An antiviral mask, comprising:

a mask body, the mask body comprising:

a layer of fibrous material comprising silicon nitride powder embedded in the fibrous material, wherein the silicon nitride is present in the inner surface at a concentration of about 1wt.% to about 15 wt.%; and is

Wherein the silicon nitride inactivates viruses that come into contact with the layer of the mask body.

2. The antiviral mask of claim 1, further comprising a second layer of material surrounding the fibrous material.

3. An antiviral mask as in claim 1, wherein said fibrous material comprises a spunbond nonwoven fabric.

4. An antiviral mask as in claim 3, wherein said spunbond nonwoven fabric comprises polypropylene.

5. The anti-viral facial mask according to claim 1, wherein droplets or aerosols containing the viruses are captured by fibers in the fibrous material, whereby the viruses are brought into contact with the silicon nitride embedded in the fibrous material, and the silicon nitride powder inactivates the viruses.

6. The anti-viral mask according to claim 1, wherein the virus is in contact with the silicon nitride powder for a duration of at least 1 minute.

7. The antiviral mask of claim 1 wherein said silicon nitride in said layer of fibrous material is present at a concentration of less than about 10 wt.%.

8. The anti-viral mask according to claim 1, wherein the virus is SARS-CoV-2.

9. An antiviral mask, comprising:

a mask body; and

one or more filters in the mask body, each filter of the one or more filters comprising:

a layer of fibrous material comprising a silicon nitride powder impregnated in the layer of fibrous material, wherein the silicon nitride is present at a concentration of about 1wt.% to about 15 wt.%;

wherein the silicon nitride inactivates viruses in contact with the one or more filters of the anti-viral mask.

10. An antiviral mask as in claim 9, wherein said fibrous material comprises a spunbond nonwoven fabric.

11. An antiviral mask as in claim 10, wherein said spunbond nonwoven comprises polypropylene.

12. The anti-viral facial mask according to claim 9, wherein droplets or aerosols containing the virus are captured by the fibrous material, whereby the virus is brought into contact with the silicon nitride embedded in the fibrous material, and the silicon nitride powder inactivates the virus.

13. The anti-viral mask according to claim 9, wherein the virus is in contact with the silicon nitride powder for a duration of at least 1 minute.

14. The antiviral mask of claim 9 wherein the silicon nitride in each filter is present at a concentration of less than about 10 wt.%.

15. The anti-viral mask according to claim 1, wherein the virus is SARS-CoV-2.

16. A method of preventing the spread of a virus, the method comprising:

providing an anti-viral face mask according to claim 1 to a wearer, wherein the silicon nitride powder inactivates the virus when the virus contacts the fibrous material of the face mask.

17. A method of embedding silicon nitride powder in a fibrous material, the method comprising:

pretreating the fibrous material in at least one pretreatment tank;

embedding silicon nitride particles in the fiber material using sonication in an ultrasonic bath;

drying the fibrous material and thermally bonding the silicon nitride particles in a drying and thermal bonding oven;

rinsing the fiber material in an ultrasonic rinsing tank to remove excess silicon nitride particles; and

the washed fibrous material is dried in a drying oven.

18. The method of claim 17, wherein the at least one pretreatment tank comprises an ultrasound transducer array and contains water and/or a coupling agent.

19. The method of claim 17, wherein the ultrasonic tank comprises an ultrasonic transducer array and contains water, a dispersant, and silicon nitride particles.

20. The method of claim 17, wherein the ultrasonic irrigation bath comprises an ultrasonic transducer array and contains water and a surfactant.

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