The present invention relates to the field of air filtration, in particular to a polytetrafluoroethylene composite filter material and a preparation method and uses thereof. The polytetrafluoroethylene composite filter material comprises a support layer and a polytetrafluoroethylene microporous membrane layer, and the support layer and the polytetrafluoroethylene microporous membrane layer are compounded by an adhesive, wherein the adhesive comprises a two-component polyurethane adhesive, a pore forming agent and an inorganic filler. The present invention adopts a two-component solvent-free polyurethane adhesive, and by adding a low-temperature pore forming agent and an inorganic filler, the pore forming agent forms an irregular pore channel structure at the bonding interface during curing, and the inorganic filler prevents the adhesive from entering the micropores of the polytetrafluoroethylene membrane, so that the air permeability and filtration efficiency of the polytetrafluoroethylene microporous membrane are not affected after compounding; and the prepared polytetrafluoroethylene composite filter material has good air permeability, high peel strength, good filtration efficiency and good barrier effect.

Compositions and articles comprising a non-woven matrix for use as anti-microbial filters are provided. In some embodiments, the non-woven matrix comprises nanofibers suitable for capturing a droplet comprising a microbe (e.g. a virus particle). In some embodiments, the non-woven matrix comprises a biocide suitable for reducing propagation and/or inactivating a microbe.

The present invention discloses a Fe—Al-based metal porous membrane and a preparation method thereof, which relate to the technical field of industrial gas-solid and liquid-solid separation and purification, and mainly address problems in the prior art, such as cracking-prone and peeling of a membrane layer of an existing Fe—Al-based metal porous membrane during its preparation and use. The preparation method of the present invention comprises the steps of: adding a Fe—Al-based metal powder and a metal fiber powder into an organic-additive-added water-based solvent, and mixing them into a slurry; tape casting the slurry, through a tape casting machine, to form a membrane green body on a metal substrate layer, and letting it dry; and placing the dried membrane green body in a sintering furnace, to remove organic substances and perform high-temperature sintering and predetermined-temperature reaction synthesis.

The present invention relates to the field of air filtration, in particular to a polytetrafluoroethylene composite filter material. The polytetrafluoroethylene composite filter material comprises a supporting layer and a polytetrafluoroethylene film layer, wherein the supporting layer is a silver-plated carbon nanomaterial-modified meltblown nonwoven fabric. The polytetrafluoroethylene composite filter material is prepared by fiberizing a resin material modified by silver-plated carbon nanomaterial on the surface of a polytetrafluoroethylene film by a melt-blowing method. The polytetrafluoroethylene composite filter material of the present invention combines filtering and sterilizing functions, has higher filtering efficiency and filtering precision, has the functions of sterilizing and killing viruses, has a good isolation effect, and greatly prolongs the service life of the filter material.

The present disclosure relates generally to air filtration devices. More specifically, but not exclusively, the present disclosure relates to an air filtration device comprised of a copper (or copper alloy) medium to inactivate airborne pathogens (e.g., viruses, bacteria, coronaviruses, COVID-19, etc.) and mitigate harmful exposure to said pathogens. The copper medium is a porous mesh (i.e., copper wool) that is positioned within or on a structure to provide support. The air filtration device may be positioned in an HVAC system such that an air stream flows through the copper medium to inactivate airborne pathogens, such as viruses, in the air stream. The air filtration device may be used in combination with, or in addition to, existing HVAC system conventional air filters (e.g., HEPA filters). The air filtration device includes a copper medium positioned on a face mask to inactivate airborne pathogens during respiratory processes.

The present disclosure provides devices and methods for filtering a fluid. An example device can include a first end configured to be joined to a first segment of a pipe. The first end can include a first opening for receiving the fluid. The device can also include a second end configured to be joined to a second segment of the pipe. The second end can include a second opening for transmitting the fluid. A filtering segment can be disposed between the first end and the second end. The filtering segment can include a plurality of fiber filters oriented substantially perpendicular to a direction of flow of the fluid in the pipe. A fiber filter of the plurality of fiber filters can include a mycomaterial and a carrier material configured to provide nutrients to the mycomaterial.

A provided stretched porous polytetrafluoroethylene membrane has an air permeability of 4 cm.sup.3/(sec.Math.cm.sup.2) or more, as expressed in terms of Frazier air permeability, in a thickness direction, and has a total cohesion of 1.9 (N/20 mm).sup.2 or more, the total cohesion being expressed by a product of a peel cohesion in a first in-plane direction and a peel cohesion in a second in-plane direction perpendicular to the first direction. The above stretched porous membrane is highly air-permeable and, for example, when included in a filter member, being less likely to suffer breakage at the time of handling the member or placing the member on a housing or the like.

An object of the present invention is to provide a filtering device which makes it possible to obtain a chemical liquid having excellent performance and enables filter media to have sufficiently long pot life. Another object of the present invention is to provide a purification device, a chemical liquid manufacturing device, a filtered substance to be purified, a chemical liquid, and an actinic ray-sensitive or radiation-sensitive resin composition. A filtering device according to an embodiment of the present invention has a first filter unit including a first filter, which satisfies at least one condition selected from the group consisting of following conditions 1 to 3, and a housing accommodating the first filter and a second filter unit including a second filter different from the first filter and a housing accommodating the second filter, in which the first filter unit and the second filter unit are independently disposed in a pipe line through which a substance to be purified is supplied. Condition 1: the filter has a filter medium including two or more layers containing materials different from each other. Condition 2: the filter has a filter medium including two or more layers having different pore structures. Condition 3: the filter has a filter medium including one layer in which different materials are mixed together.

A provided stretched porous polytetrafluoroethylene membrane has a node-fibril structure including a plurality of nodes and a fibril connecting the plurality of nodes. A ratio of an average length of the plurality of nodes in a thickness direction of the stretched porous polytetrafluoroethylene membrane to a thickness of the stretched porous polytetrafluoroethylene membrane is 10% or more. The above stretched porous polytetrafluoroethylene membrane is less likely to suffer breakage. In the above stretched porous polytetrafluoroethylene membrane, assuming that there is a cuboid region having an upper surface and a lower surface respectively positioned at one membrane surface and the other membrane surface of the stretched porous polytetrafluoroethylene membrane, the number of the nodes included in the region may be 4 or less per micrometer thickness, the upper surface and the lower surface each having dimensions of 280 μm×280 μm.

Provided is a porous polytetrafluoroethylene membrane in which an absolute value of a difference in lightness between one principal surface and the other principal surface is 1.0 or more, where the lightness is lightness L* of CIE 1976 (L*, a*, b*) color space specified in JIS Z8781-4: 2013. The porous polytetrafluoroethylene membrane may be colored black or gray. The porous polytetrafluoroethylene membrane provided can have properties with a reduced coloring-induced deterioration.