A tetrafluoroethylene polymer is provided in an air filter medium having a pressure loss that can be reduced and made uniform at a plurality of positions. The tetrafluoroethylene polymer may also be provided in an air filter medium, a filter pack, or an air filter unit. The tetrafluoroethylene polymer has drawability and non-melt processability. The tetrafluoroethylene polymer has a ratio S.sub.2/S.sub.1 of 0.60 or more, where S.sub.2 represents an endotherm mJ/mg in a range of T.sub.0° C. or higher and 350° C. or lower, T.sub.0° C. is a temperature 2.5° C. lower than a temperature T.sub.p° C. (340≤T.sub.p≤345) at which a minimum point is given on a heat-of-fusion curve obtained by measuring an unbaked polymer for measurement having no history of heating to a temperature of 300° C. or higher using a differential scanning calorimeter at a temperature-increasing rate of 2° C./min, and S.sub.1 represents an endotherm mJ/mg in a range of 320° C. or higher and T.sub.0° C. or lower.

Disclosed herein is a molecular imprinted protective face mask comprising a supportive structure, a surface material that receives and retains a molecular imprint and that is positioned to contact airborne molecules during use, a molecular imprint of a bioactive molecule wherein an imprinted cavity is at least one of a bioactive molecule with a molecular configuration that captures a specific airborne and/or microdroplet-borne molecule and a protein with a binding site that captures a specific molecule.

Disclosed herein is a molecular imprinted protective face mask comprising a supportive structure, a surface material that receives and retains a molecular imprint and that is positioned to contact airborne molecules during use, a molecular imprint of a bioactive molecule wherein an imprinted cavity is at least one of a bioactive molecule with a molecular configuration that captures a specific airborne and/or microdroplet-borne molecule and a protein with a binding site that captures a specific molecule.

Exemplary embodiments of filter media and methods of making and using them are disclosed.

A specially functionalized composite filter material with a high specific surface area is used to adsorb PFAs from potable water. In a preferred embodiment, the base filter material is granular activated carbon (GAC), which is sequentially coated with a thin layer of polydopamine, a thin layer of partially oxidized iron, and a thin coating of octadecylamine. After PFAs are adsorbed onto the coated GAC particles, the PFAs are removed by a rinsing process, and remain in the rinse effluent. GAC particles are recovered and recoated as needed to restore their adsorptive capacity. The PFA-containing effluent is treated using photochemical processes to destroy the PFA molecules. The now PFA-free effluent can be disposed of as a non-hazardous material. The composite filter material works in systems ranging from small passive systems for personal use to large scale, high-flow-rate utility water treatment systems.

A particulate capturing device includes: a vent pipe having a flow path space through which air containing fine particles flows; an air flow generating portion configured to generate an air flow flowing in a direction in which the air is to he sent in the flow path space of the vent pipe; and a collecting portion disposed in a state of crossing the flow path space of the vent pipe in a direction intersecting the air flow, and configured to collect the fine particles contained in the air, in which the collecting portion is formed of a vent plate having a thickness of 5 mm or less and having plural vent portions with an opening size of 0.005 mm or more and 0.1 mm or less.

A filter medium of the present disclosure has a laminate structure composed of a first polytetrafluoroethylene (PTFE) porous membrane, a first air-permeable supporting member, a second PTFE porous membrane, and a second air-permeable supporting member laminated in this order. The first PTFE porous membrane constitutes an exposed surface of the filter medium. A ratio of a transmittance of the first PTFE porous membrane to a transmittance of the second PTFE porous membrane is 100 or more. The filter medium of the present disclosure is a filter medium which includes the PTFE porous membranes, from which dust deposited on a surface over a period of use can be easily removed, and which has excellent reusability demonstrated by reduction of a filtration performance decrease caused by removal of dust.

A polishing filter employed within a sump pump system for removing mineral oils, natural ester, and synthetic ester-based fluids from an emulsion is provided. The polishing filter is disposed within a sump pump barrier and is gravity-fed a synthetic ester and water based emulsion via a polishing filter conduit. The polishing filter removes excess synthetic ester-based fluids from a water/oil emulsion fluid flowing through a barrier canister disposed within the sump pump barrier above the polishing filter and releases a resultant filtered fluid. The polishing filter cartridge contains a filtration media with a hydrophilic composition for the capture of synthetic ester-based fluid having a surface tension dissimilar to water, and the hydrophilic composition of the media has a surface energy greater than or equal to 35 dynes per centimeter.

A filter element including a filter media and methods for making the same are provided. The filter element includes a support core surrounded by a tubular ring of filter media. A first end of the tubular ring of filter media is coupled to a first end cap and a second end of the tubular ring of filter media coupled to a second end cap. The tubular ring of filter media includes a carrier media layer, a coarse filter media layer, a fine filtration media layer, a water-capturing media layer, and an outer wrap.

Provided is a filter plug, a well system, and a method for fracturing a well system. The filter plug, in one aspect, includes a filtration skeleton. The filter plug according to this aspect further includes a degradable material in contact with the filtration skeleton, the filtration skeleton and degradable material configured to lodge within a port in a wellbore, and thus substantially plug the port when the degradable material remains intact with the filtration skeleton and allow the filtration skeleton to filter particulate matter as fluid passes there through when the degradable material no longer remains intact with the filtration skeleton.