Patent Application
20240182682
The present application generally related to antimicrobial agents (e.g., pathogen inactivating materials) and, more particularly, to such agents infused within an ablative or sacrificial polymer.
Air filters for heating, ventilation, and air conditioning (HVAC) systems provide excellent filtration of particles. Depending upon the rating of the filter, smaller and smaller particles may be filtered out of the air. A specific type of filter, high efficiency particulate air (HEPA) filter, is utilized to filter micron and submicron particles from the air.
While very fine particle filters offer trapping of allergens and other problematic materials such as fine dust, all of these passive air filters do not allow for the inactivation of pathogens that may be borne by the air as it flows through the HVAC system. High Efficiency Particulate Air (HEPA) filters may also cause a high pressure drop across the filter, resulting in poor airflow through the HVAC system.
Thus, there is therefore a need for a long-lasting, pathogen inactivating, and high percentage capture air filter for HVAC systems that minimizes the pressure drop in the air flow after the filter.
The embodiment is the use of air filter or filters comprised of paper, woven fiberglass, nonwoven fiberglass, nonwoven polymers, and the like where the air filter or filters further comprise a method of inactivating pathogens through the use of a compound or compounds that are infused or coated into or onto the air filters.
The air filter or filters further comprise a polymer that is infused or mixed with a compound, such as an antimicrobial agent (e.g., a biocide or pathogen inactivating material), that will kill or inactivate pathogens such as viruses, bacteria, and/or fungi. The polymer may also have ablative or sacrificial characteristics where the surface of the polymer may wear away with time (as described and defined in greater detail below), exposing a new fresh surface of the polymer. While in many instances this application will refer to a pathogen inactivating material, in all such instances the application should be read to support the concept that the pathogen inactivating material can be any antimicrobial agent (which as a class is broader than pathogen inactivating materials), e.g., any substance that can kill and/or inhibit the growth of any microorganism such as bacteria, viruses, fungi, etc., on contact or interaction.
The ablative or sacrificial polymer may be an emulsion polymer comprised of a polyvinyl acetate and acrylate backbone where the outer surface of the polymer will be worn away over time, exposing a new surface to the environment.
The ablative or sacrificial polymer may also be from the group of polycaprolactone (PCL), poly(lactic-co-glycolic acid) (PLGA), and polyglycidyl methacrylate (PGMA). These polymers will degrade readily in standard temperature and pressure (STP) conditions such as the environment of an office building, school, or residence. In the case of a residence, the residence may be temporary, such as a hotel or motel, or permanent, such as a house or apartment.
The pathogen inactivating material or biocide infused polymer may also be compounded such that, when coated onto the filter substrate, provides a supply of the pathogen inactivating material or biocide to the air that is flowing through the filter. Through the wearing away of the polymer, in various embodiments, the supply of pathogen inactivating material can be supplied to the air continuously and/or intermittently.
One method of accomplishing this is to introduce a large excess of pathogen inactivating material or biocide into the polymer mixture such that the pathogen inactivating material or biocide comes to the surface of the polymer through surface energy, diffusion, capillary action, or other passive transport mechanisms.
Yet another method of supplying a replenishing (continuously or intermittently) amount of pathogen inactivating material is for the ablative or sacrificial polymer matrix to wear away over time while continuously exposing the pathogen inactivating material that has been infused into the polymer matrix to the environment.
The polymer matrix may refer to the ablative or sacrificial polymer alone or the ablative or sacrificial polymer infused or mixed with other materials, such as a pathogen inactivating material.
The polymer that is coated on the filter system may also be of such a nature that it is incompatible with the biocide or pathogen inactivating material such that the biocide or pathogen inactivating material, or any other material that would inactivate a pathogen, is allowed to ooze or flow out of the polymer matrix. This would be similar to a permanently oiled bearing where oil is infused into a sintered bearing and thus has long life lubrication as the oil oozes out of the sintered bearing. The polymer matrix may be a solid, solution, or emulsion type. The polymer may be borne by an organic solvent or may be waterborne or maybe 100% solids.
The pathogen inactivating material or biocide may be a blend of pathogen inactivating materials or biocides, each having a different target area of pathogens. As a result, multiple pathogens, such as Legionella, the pathogen causing Legionnaires' disease, and SARS-CoV-2, the virus causing the Covid-19 pandemic, may be inactivated at the same time. Also, bacteria and fungi may be inactivated.
Filter papers are used in many types of applications including air filters for HVAC units and automobiles, coffee filters, fuel filters, chromatography separation, laboratory filters, and teabags to name a few applications. Porous air filters in HVAC systems may be manufactured in a manner to allow particles of different sizes to be trapped while other sizes may pass through the filter.
These filter papers have benefited from continued refinement and engineering to provide sustained and precise filtration methods for various materials.
Single-digit and fractional micron filtration is possible with many different types of filter paper. The filter papers may also be treated with biocides and pathogen inactivating material s to improve the protection from infectious particles that may be circulating in the air.
The coating of the filter substrate may be accomplished by a spray, dip, roll, print, or other transfer process whereby an ablative or sacrificial polymer is transferred to the surface of the specialty paper. The ablative or sacrificial polymer may contain pathogen inactivating material such as a biocide or pathogen inactivating material. The roll process may be a Mayer rod process or a gravure process.
A fiberglass base material may be utilized for the HVAC filter. Here, the ablative or sacrificial polymer with a biocide or a pathogen inactivating material, or any other material that would inactivate a pathogen, is transferred to the fiberglass substrate. The fiberglass substrate may be woven or nonwoven. The ablative or sacrificial polymer will wear away over time and expose a new surface to the environment while it is coated on the fiberglass substrate.
The rating of the air filter may be of various levels. The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) utilizes the standard as prescribed by ANSI/ASHRAE 52.2 for the Minimum Efficiency Reporting Value (MERV). A standard of MERV 13 or higher has been prescribed by the Center for Disease Control (CDC).
There are various antimicrobial agents (e.g., biocides and pathogen inactivating materials) available in the marketplace for the inactivation of pathogens, including the SARS-CoV-2 virus that is causing the Covid-19 pandemic. The biocides and pathogen inactivating materials include materials that incorporate chlorinated molecules such as quaternary ammonium salts with a chlorine molecule attached. Benzalkonium chloride is an example of a material with a quaternary ammonium component and a chlorine component. Many other types of biocides and pathogen inactivating materials are available such as sodium hypochlorite (commonly known as bleach), hydrogen peroxide, and isopropyl alcohol. Other molecules include boron, iodine, and other chlorine containing molecules.
The polymers that are utilized in this embodiment have special characteristics for the changes of the polymers over time. Both ablative polymers and sacrificial polymers may be utilized for the coating material on the air filters. Ablative polymers tend to break down from the surface due to external forces such as the flow of a fluid, such as air, over the surface of the ablative polymer. Sacrificial polymers tend to break down in a bulk manner where the entire sacrificial polymer begins to break down from external forces such as the flow of the fluid over the surface of the sacrificial polymer. Various polymeric properties may be manipulated to produce either an ablative polymer or a sacrificial polymer.
In one aspect, embodiments of the disclosure related to a polymer matrix that includes a polymer mixed with an antimicrobial agent, where the polymer is an ablative polymer or a sacrificial polymer that will degrade over time in either a surface or bulk degradation method.
In various embodiments, the polymer matrix can also include a degradation labile molecule built into a backbone of the polymer. In some instances, the degradation molecule is polymerized into the backbone of the polymer. In some instances, the degradation molecule is copolymerized into the backbone of the polymer. The polymer matrix can also include an enzyme adapted to increase the speed of the degradation of the polymer matrix either through an ablative process or a sacrificial process. In some cases, the polymer matrix has a high second Damköhler number (e.g., greater than 1). In other cases, the polymer matrix has a low second Damköhler number (e.g., less than 1). The polymer matrix can also include an absorptive material (e.g., silica gel, molecular sieve, clay, or zeolite material). The antimicrobial agent can be a pathogen inactivating material and/or a biocides. In some embodiments, the disclosure relates to an air filter that includes a substrate and the polymer matrix.
In another aspect, embodiments of the disclosure relate to a method of making a polymer matrix, the method including the steps of: mixing a polymer with an antimicrobial agent, where the polymer is an ablative polymer or a sacrificial polymer that will degrade over time in either a surface or bulk degradation method.
In various embodiments, the method can include the step of building a degradation labile molecule into a backbone of the polymer and/or adding an enzyme adapted to increase the speed of the degradation of the polymer matrix either through an ablative process or a sacrificial process. In some cases, the polymer has a high second Damköhler number. In some cases, the polymer has a low second Damköhler number. In some embodiments, the method includes adding an absorptive material.
The foregoing aspects and other features of the disclosed embodiments are explained in the following description, taken in connection with the accompanying drawings, wherein:
The embodiments described herein disclose a HVAC filters system that is coated with a polymer where the polymer contains an agent for inactivating viruses. Specifically, the pathogen inactivating material in the polymer is used to inactivate the SARS-CoV-2 virus causing the Covid-19 pandemic.
The polymer may be an ablative or sacrificial polymer that will wear away at the surface over time, thus exposing new material to the environment. The polymer may also be a material that's incompatible with the inactivating agent such that the inactivating agent, a biocide or pathogen inactivating material for example, will ooze out of the polymer for a long period of time and thus inactivate viral particles when they impinge on the filter coated with this polymeric configuration.
An ablative or sacrificial polymer may also be known as a sacrificial material with the polymer subject to wear from environmental conditions. The ablation of a polymeric matrix may occur from thermal interaction, UV interaction, and other energetic, oxidating, or hydrogenating environmental interactions. The ablative or sacrificial polymer may also be comprised of nano composites. The sacrificial polymer may wear away and/or break down from environmental interactions.
The polymeric material, blended with a pathogen inactivating material, or any other pathogen inactivating material, may be applied to the substrate by various means such as spraying, dipping, roll coating, and printing. Once the polymer is applied to the substrate, it may be cured or dried through various processes such as UV cure, drying in a heated oven, or air dried.
Test procedures, such as ISO-18184:2019, may be utilized to demonstrate the anti-viral capacity of a porous substrates. In accordance with ISO-18184:2019, samples of a non-woven fiberglass with a MERV rating of 13 treated with a polyvinyl acetate/acrylate copolymer infused with Stepan BTC-885, a benzalkonium chloride containing mixture, were tested. A material containing essentially 99.9% benzalkonium chloride was also tested. The pathogen that was tested utilizing the ISO-18184:2019 standard was the SARS-CoV-2 virus, WA1 strain. The results of the testing show that the polymer and pathogen inactivating material infused non-woven fiberglass MERV 13 filter inactivated all of the SARS-CoV-2 WA1 virus in 15 minutes. The test results are listed below in Table 1.
The substrate that the polymer is coated onto may be composed of various materials. The materials include both woven and nonwoven fiberglass, paper, nonwoven polymeric matrices, woven polymeric matrices, and similar support materials.
A second set of testing was undertaken to determine the effect of a specific level of pathogen inactivating material. Table 2 is a listing of the test material.
The materials in table 2 were tested against the SARS-CoV-2 virus, Washington strain, utilizing a modified protocol as delineated in ISO-18184. The results are shown in table 3.
Utilizing the coated filter, IPAC-06272022-003, a reduction in the amount of virus was shown versus the uncoated material control, IPAC-06272022-004. Thus, the polymer matrix infused with a pathogen inactivating material showed an inactivation of the SARS-CoV-2 virus.
A third set of results show the data in table 3 where different levels of benzalkonium chloride were infused into the polyvinyl acetate/acrylate polymer. The benzalkonium chloride in this test was a 99.5% material while the BTC-885 material is 50% active with the other 50% being surfactant materials.
Table 5 shows the results of the testing of the materials in table 2.
This test is designed to evaluate the virucidal effectiveness of the polymer matrix consisting of at least a base ablative or sacrificial polymer and a pathogen inactivating material infused into the polymer matrix against SARS-associated Coronavirus Type 2 (SARS-CoV-2). The test determined the virucidal effectiveness of the pathogen inactivating material (indeed any antimicrobial agent) infused polymer matrix to inactivate the test virus via direct contact. The test is designed to simulate consumer use; and is based on the International Standard ISO 18184 method, “Textiles—Determination of Antiviral Activity of Textile Products”.
The results show the complete inactivation of the SARS-CoV-2 virus at a 10% level of the pathogen inactivating material and a complete inactivation to a 4.03 log reduction of the SARS-CoV-2 virus at a 5% level of the pathogen inactivating material.
The polymeric coated substrate may then be fitted into a frame such that it may easily be inserted into an HVAC system that currently accepts regular types of filtration media.
Another pathogen inactivating material is hypochlorous acid (HOCl). It has virucidal efficacy against viruses such as SARS-CoV-2. HOCl exists naturally in the human body. It is created by white blood cells as a defense system against infection, bacteria, fungi, and viruses. HOCl attacks invading pathogens by breaking down cell walls. HOCl as an antimicrobial acid is lethally effective as the body's natural response to bacteria. Thus, HOCl may be utilized as an effective virucidal and biocidal agent in an air filter device.
Another pathogen inactivating material is didecyldimethylammonium chloride (DDMAC). It is a broad spectrum bactericide, pathogen inactivating material, and fungicide and can be used as disinfectant cleaner for linen, recommended for use in hospitals, hotels and industries.
Yet another pathogen inactivating material is chlorhexidine. It is a broad spectrum disinfectant and antiseptic utilized in surgical procedures.
Other pathogen inactivating materials may also be utilized. These include chlorinated material, quaternary ammonium salts, peroxides, acids, bases, and others.
The inventors appreciate and recognize that, at a molecular level, almost all materials are constantly in a state of change and, in its most extreme construction, one could take the position, at the molecular level, that most materials and objects are wearing away at all times. However, in this application, Applicant is acting as its own lexicographer and uses “wear away” having a very particular meaning as described in the following disclosure.
The change that occurs polymers over time takes place in various forms. Two major changes typically observed are surface changes and bulk changes of the polymer matrix. One measurement for the active transport process in polymers is the second Damköhler number. The Damköhler number was defined by German chemist Gerhard Damköhler in 1936 and is commonly used to characterize the relative magnitude of convection time scale and chemical reaction time scale. In its most commonly used form, the first Damköhler number relates the reaction timescale to the convection time scale, volumetric flow rate, through the reactor for continuous (plug flow or stirred tank) or semi-batch chemical processes or general chemical reaction processes. The second Damköhler number relates to diffusion-controlled chemical reaction processes. Thus, the second Damköhler number tends to be an indicator of either surface or bulk degradation of a polymer.
In reacting systems that include interphase mass transport, the second Damköhler number (Da
The second Damköhler number may be utilized to describe surface versus bulk degradation based on the mass transfer of materials at the polymer/environmental interface.
Where keff=reaction rate constant with units of time of 1/seconds, DH
Bulk degradation is the breaking of any polymer bond breaking at any time. An example of this is hydrolytic degradation where water diffuses freely through out the polymer structure. As a result of the bulk degradation, the volume remains constant but the chemical bonds decrease in number.
Surface degradation, on the other hand, is where only the polymer bonds on the surface are degraded and the core of the polymer remains intact. As a result of the constant surface degradation, the volume will decrease with time but within the remailing solid, the bonds are constant.
Thus, very high keff and a low DH
Ablative polymers will be associated with a very high keff and a low DH
Polymers with surface degradation will have a high second Damköhler number while polymers with bulk degradation will have a low second Damköhler number. In some embodiments, polymers exhibiting surface degradation will have a second Damköhler number greater than 1 (e.g., in a range from 1-2, 1-3, 1-5, or 1-10). In some embodiments, polymers exhibiting bulk degradation will have a second Damköhler number less than 1 (e.g., in a range from 0-1, 0-0.5, or 0.5-1).
The second Damköhler number (Da
This process is also seen in degradable sutures. Typically, the absorbable stitches or degradable sutures are copolymers of poly glycolic acid, PGA, and poly lactic acid, PLA. Starting with a homopolymer of PGA, there is lower diffusivity of water and thus a longer time to degrade. As more PLA is copolymerized with PGA, the diffusivity of water increases and the degradation increases as well. However, what may be somewhat counterintuitive, a homopolymer of PLA has a similar or slightly longer time of degradation as does a homopolymer of PGA due to the low diffusivity of water for the homopolymer of PLA. The low diffusivity of water is due to the ordered polymer chains for the homopolymer of PGA in the homopolymer of PLA. When a copolymer is produced, the polymer becomes more amorphous and allows for a higher diffusivity of water and thus a faster degradation. So, dissolvable sutures may be throttled as to their dissolution rate depending upon the ratio of the PGA to PLA in the copolymer making up the sutures. They may also be throttled as to their dissolution rate based on the tacticity, in and out of plane bending, of the polymer constituents (PLA has an extra methyl group versus PGA and thus a different tacticity).
A degradation labile molecule may be built into the backbone of the polymer so as to increase the ablation or sacrifice of the polymer over time. This degradation labile molecule may include a starch molecule or a cellulose molecule.
The degradation labile molecule may also be subject to enzymatic degradation through the use of a specific enzyme that is incorporated into the polymer matrix.
The enzyme in the polymer matrix may be encapsulated so as to be released over time. The encapsulation of the enzyme may be such that the encapsulation will degrade and release the enzyme at different time intervals. This may be accomplished through the use of the material such as polyvinyl alcohol where the molecular weight of the polyvinyl alcohol is modified to increase or decrease the degradation of the encapsulation portion of the encapsulated enzyme.
The activation of the enzymatic process may also be triggered by an external event such as a change in pH or a change in the humidity of the air flowing through the air filter.
The tacticity of the polymer will also have an effect on the degradation of the polymer matrix. The tacticity of a polymer is the relative stereochemistry of adjacent chiral centers within a macromolecule such as a polymer. The changes in the stereochemistry will allow for more or less diffusivity into the polymer matrix of materials that will cause degradation of the polymer matrix, such as water.
The release of the pathogen inactivating material or biocide from the ablative or sacrificial polymer may also be modulated through the use of oil absorbent materials such as silicas, talcs, clays, molecular sieves, materials with a high degree of porosity such as diatomaceous earth, Zeolites, silica gel and other absorptive materials that may be incorporated into the polymer matrix. The oil absorption indicates how much resin or polymer the mineral absorbs, also known as the resin demand.
The absorptive materials may be microporous, mesoporous, or macroporous. Microporous materials will have pores that are less than 2 nm. Mesoporous materials will have pores from 2 nm to 50 nm. Macroporous materials will have poor openings from 20 to 100 nm.
Release of a pathogen inactivating material or biocide from the oil absorptive materials will depend upon the environmental conditions once they are exposed to the environment after the sloughing off of the ablative polymer or the breakdown of the sacrificial polymer. Temperature, atmospheric pressure, and humidity will play a role in the release of the pathogen inactivating material or biocide from the absorptive materials once exposed to the environment.
The ablation or sacrifice of the polymer matrix may be modulated through the modification of the polymer matrix by the incorporation of materials such as cellulosic materials and starch materials. The process of ablation or sacrifice of the polymer matrix may be increased through the use of hydrophilic moieties and enzymatic materials which will help to increase the speed of degradation, either through ablation or sacrificial processes, of the polymer matrix.
The ablation or sacrifice of the polymer matrix may also be modulated through the modification of the polymeric bonds so as to increase or decrease the ablation or sacrifice of the polymeric matrix. For instance, ester bonds may be grafted into the backbone of the polymer matrix to allow for an area of chain scission via hydrolysis from interaction with water molecules.
Another molecule that may be grafted into the backbone of the polymeric matrix are starch molecules. For instance, a polyvinyl acetate-starch copolymer may be produced.
A polyvinyl acetate butyl acrylate copolymer may also be copolymerized with the starch molecule such that a starch molecule is built into the backbone of the vinyl acetate butyl acrylate copolymer.
The use of a starch enzyme may allow for cleavage of the polymer backbone of the vinyl acetate butyl acrylate copolymer starch complex. One such enzyme is amylase. The enzymatic action of the amylase enzyme will allow for the breakdown of the polymeric matrix over time.
Another molecule may be grafted into the backbone of the polymer matrix is cellulose. A cellulose type molecule grafted into the backbone of a vinyl acetate acrylic acid copolymer, such as a vinyl acetate butyl acrylate copolymer or a vinyl acetate 2-ethyl hexyl acrylate copolymer will allow the polymeric matrix to be susceptible to both surface breakdown, and thus a ablative polymer matrix, and bulk breakdown, and thus a sacrificial polymer matrix.
Enzymes that will act on the cellulosic portion of a vinyl acetate acrylic acid cellulose polymer matrix include cellulase, cellobiohydrolase, and beta-glucosidase.
The polymer matrix with molecules polymerized into the backbone, such as starch and cellulose, may be blended with appropriate enzymes such that the polymer matrix will break down over time. The enzymes may be blended into the polymer matrix in a large amount or a small amount, depending upon how fast the polymer matrix is intended to break down over time.
In another embodiment, the enzyme is encapsulated in a secondary polymer, such as polyvinyl alcohol. This encapsulated enzyme is then incorporated into the polymer matrix, such as a vinyl acetate butyl acrylate copolymer, a vinyl acetate 2-ethyl hexyl acrylate copolymer, or modified version of a polymeric matrix such as a starch or cellulose modified version of a polymeric matrix.
As the ablative or sacrificial polymer degrades, the encapsulated enzyme may be released so as to further degrade the polymeric matrix. The encapsulating polymer for the enzyme may be modified to degrade at different rates depending upon the intended degradation of the polymer matrix. Also, the amount of the encapsulated enzyme in the polymer matrix may be modified so as to modify the ablative or sacrificial nature of the polymer matrix.
The enzymatic material may also be adsorbed onto adsorptive substrate such as silica gel, molecular sieves, and zeolites. This will allow the enzymatic material to be released over time as it desorbs from the adsorptive substrate.
Natural polymers, such as a mixture of amylose and amylopectin, may also be utilized as a polymer matrix. Here, amylase may be utilized as an enzymatic degradation material to break down the amylose and amylopectin.
Enzymes may also be utilized to scission the backbone of the polymer forming the polymer matrix. These include both lipases and esterases. Enzymes act in a “lock” and “key” methodology where the enzyme will catalyze a chemical process at a high rate of reaction by temporarily bonding to a molecule (the “key”) to turn on a chemical reaction (the “lock”) and produce a new reaction product. This enzymatic interaction typically lowers the activation energy of the reaction process.
The enzymatic process may be throttled through several means including changes in pH, the elimination or addition of enzymatic cofactors, the addition of inhibitors that will bind to enzymatic sites, and changes in temperature. This enzymatic throttling process may be used to increase or decrease the ablative or sacrificial nature of the polymeric material.
Thus, several types of polymer matrix are described wherein a chemical moiety, such as a starch or cellulose, may be polymerized into the backbone of the polymer matrix so as to facilitate the ablative or sacrificial nature of the polymer matrix. This process may also be modified through the use of enzymatic materials where the enzymatic materials themselves may be modified to be more or less active through both encapsulation and enzymatic inhibition.
The coating of a substrate with the polymer matrix may be seen, in one aspect, by various magnifications of a scanning electron microscope (SEM). The polymer matrix is an ablative or sacrificial polymer infused with a pathogen inactivating material.
A micrograph of uncoated fiberglass fibers in a nonwoven configuration 150 is shown at 50 times magnification in
In
In
In
Air flow tests for a nonwoven fiberglass MERV-14 substrate were conducted utilizing two test criteria. The first test criteria was the airflow through an uncoated nonwoven fiberglass substrate and a nonwoven fiberglass MERV-14 substrate that was spray coated with an emulsion polymer matrix containing a polyvinyl acetate 2-ethylhexyl acrylate polymer infused with a Stepan BTC-885 pathogen inactivating material. The test performed was ASTM D-737 Air Permeability Test utilizing an SDL Atlas MO21A air permeability tester.
The results of the airflow testing of the nonwoven fiberglass materials may be seen in Table 6. The units of measure are ft3/minute/ft2. Sample 001 is an uncoated nonwoven fiberglass substrate and Sample 002 is a coated fiberglass substrate. It may seen that the air flow is similar for the both the uncoated substrate and the coated substrate.
Thus, the spray coating of the pathogen inactivating material infused polymer matrix applied to the nonwoven substrate did not interfere with the airflow through the MERV-14 nonwoven fiberglass substrate.
The flow of particles through both an uncoated and a coated substrate was tested utilizing NIOSH procedure TEB-APR-STP-0059 on a Automatic TSI 8130 filter tester.
Table 7 shows the results of the particle air flow test utilizing the Automatic TSI 8130 filter tester.
pm)
.17
1442 3 AFS
.
8
1442 3 AFS
1442 3 AFS
2.72
1442 3 AFS
1441 3 AFS
1441 3 AFS
1441 3 AFS
1441 3 AFS
A bank cell indicates that no data was available.
indicates data missing or illegible when filed
The IPAC-001-14-DEC-21 sample is the control with no polymer matrix coated on the fiberglass substrate and the IPAC-002-14-DEC-21 sample is spray coated with the pathogen inactivating material infused polymer matrix. The fiberglass substrate is a nonwoven MERV-14 filter material.
The test material and preconditioning of the samples for the particle transmission in accordance with NIOSH procedure TEB-APR-STP-0059 are shown in table 8.
The test results in table 7 show that there is no difference in the particle flow between the uncoated sample and the coated sample.
In the case of a spray process, the particles in the spray stream may be modified so as to penetrate into the woven or nonwoven substrate that is being utilized as the base material for the air filter. This may be done through regular atomization of the polymer matrix and pathogen inactivating material mixture. The atomization of the spray of the polymer matrix and pathogen inactivating material matrix solution may also be enhanced through various methods such as the use of a high velocity low pressure (HVLP) spray nozzle. A piezoelectric spray nozzle may also be utilized to improve the atomization of the polymer matrix and pathogen inactivating material solution.
In one aspect of the polymer matrix with the pathogen inactivating material, an indicator dye or colorants may be utilized so as to indicate the coverage of the sprayed material onto a substrate. An indicator dye or colorants may be utilized also to indicate the lifespan of the filter system and when a replacement is necessary. For instance, a blue dyed may be added to the polymer matrix and pathogen inactivating solution such that, after the solution is sprayed and dried onto a substrate, the die will fade over time, such as 30 days, the indicate the need for the replacement of the air filter.
The air filter may also have a means for detecting viral material that is impinged upon the filter. One such means for detecting the viral material is the utilization of single-stranded DNA couple to a microchip. When a material binds to the single-strand DNA, such as a single-strand RNA that is characteristic of the SARS-CoV-2, a difference in electrical charge may be determined by the microchip attached to the single-strand DNA. This electrical difference in the microchip will allow for the determination of the attachment of a specific RNA strand to a detector. As more and more RNA strands attached to the single-strand DNA, more of an indication may be seen from the microchip attached to the DNA single-strand material. This will generate a signal that will show the amount of single-stranded RNA attached to the single-strand DNA and thus identify both the viral load and the variant of the virus that is being detected. For instance, a single-stranded DNA with the sequence that matches the single stranded RNA of the Delta variant of the SARS-CoV-2 virus will bind with the viral RNA and cause a change in the electrical characteristics of the biosensor chip. This will show not only that the Delta variant is present but also the amount of Delta variant that is present.
The single-stranded DNA (ssDNA) detector may also be utilized to check the efficacy of the pathogen inactivating material filter. An ssDNA detector may be mounted downstream of a pathogen inactivating material infused filter such that the air passing through the pathogen inactivating material infused filter will subsequently come in contact with the ssDNA detector. The ssDNA detector will then detect any viral load that is coming through the pathogen inactivating material infused filter, indicating that the efficacy of the pathogen inactivating material infused filter has been lessened and report this lower pathogen inactivating material all activity through an electronic communication means.
The ssDNA detector may also be utilized as part of a system to indicate viral loads in a building or structure. The detectors may be placed in various areas of the building or structure and connected into a communications system, similar to a fire reporting communications system, such that viral infections in a building or structure, such as a hospital, may be registered and recorded and dealt with appropriately.
Another aspect of this embodiment is the use of a specialized pathogen inactivating material, such as an RNA nuclease, to inactivate viral pathogens. The use of a Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR associated protein 13 (Cas13) may be utilized to cleave RNA nucleic acid sequences. In one manner, RNA nucleases cleave the phosphodiester bonds of nucleic acids in the RNA, inactivating a single stranded RNA virus (ssRNA) such as SARS-CoV-2. A phosphodiester bond is shown in
The CRISPR type of viral inactivation allows for rapid response to variance of a microorganism, e.g., a pathogen such as the SARS-CoV-2 virus. Thus, new versions of the SARS-CoV-2 virus, such as the delta variant or the omicron variant, may be quickly inactivated.
While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.
This application claims the benefit of priority to U.S. Provisional Patent Application No. 63/418,767 entitled “Pathogen Inactivating Filter,” filed on Oct. 24, 2022, the contents of which are incorporated by reference herein in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63418767 | Oct 2022 | US |
