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.

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.

Organic solvent nanofiltration membranes that include at least one polymer coated expanded polyparaxylylene (eP-PX) membrane are provided. A substrate/support layer may be positioned on one side of the ePPX membrane. In some embodiments, the substrate/support layer is sandwiched between ePPX membranes. Processes for manufacturing and using such organic solvent nanofiltration membranes are also provided. The organic solvent nanofiltration membranes are capable of separating and/or concentrating solutes from a solution comprising a lower molecular weight organic solvent with high permeability. The polymer coated ePPX membranes may also be resistant to chemical attack, resistant to gamma radiation, thermally stable, biocompatible, and strong.

Organic solvent nanofiltration membranes that include at least one polymer coated expanded polyparaxylylene (eP-PX) membrane are provided. A substrate/support layer may be positioned on one side of the ePPX membrane. In some embodiments, the substrate/support layer is sandwiched between ePPX membranes. Processes for manufacturing and using such organic solvent nanofiltration membranes are also provided. The organic solvent nanofiltration membranes are capable of separating and/or concentrating solutes from a solution comprising a lower molecular weight organic solvent with high permeability. The polymer coated ePPX membranes may also be resistant to chemical attack, resistant to gamma radiation, thermally stable, biocompatible, and strong.

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.

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.

The disclosure provides an improved process for preparing oleophobic fluoropolymers. The resulting fluropolymers were found to be effective in imparting hydrophobic and oleophobic properties to porous polymeric membranes such as PTFE. The treated PTFE membrane can reach an oleophobic level of 6 or above, (according to the AATCC-118-1997 oil repellency test method) with a low air flux loss.

A carbon dioxide (CO.sub.2) capture and utilization system captures CO.sub.2 from flue gas and utilizes the same to enhance algae or cyanobacteria growth. The system generally comprises a CO.sub.2 capture unit and a utilization unit that is in fluid communication with the CO.sub.2 capture unit. The CO.sub.2 capture unit includes a membrane CO.sub.2 absorber that captures CO.sub.2 from incoming flue gas to produce a CO.sub.2-rich solvent. The utilization unit processes the CO.sub.2-rich solvent to produce a product stream that includes CO.sub.2 and NH.sub.3 in a predetermined CO.sub.2:NH.sub.3 ratio. The product stream is delivered to a cultivation subsystem of the utilization of the unit including one or more species of algae or cyanobacteria. A method for capturing and utilizing CO.sub.2 is also provided herein.

A carbon dioxide (CO.sub.2) capture and utilization system captures CO.sub.2 from flue gas and utilizes the same to enhance algae or cyanobacteria growth. The system generally comprises a CO.sub.2 capture unit and a utilization unit that is in fluid communication with the CO.sub.2 capture unit. The CO.sub.2 capture unit includes a membrane CO.sub.2 absorber that captures CO.sub.2 from incoming flue gas to produce a CO.sub.2-rich solvent. The utilization unit processes the CO.sub.2-rich solvent to produce a product stream that includes CO.sub.2 and NH.sub.3 in a predetermined CO.sub.2:NH.sub.3 ratio. The product stream is delivered to a cultivation subsystem of the utilization of the unit including one or more species of algae or cyanobacteria. A method for capturing and utilizing CO.sub.2 is also provided herein.

An example porous composite membrane for solvent extraction is provided. The porous composite membrane includes a Janus membrane with a first side and a second side opposing the first side. The first side exhibits hydrophobic characteristics and the second side exhibits hydrophilic characteristics. At least one of the first side or the second side is sized to perform nondispersive membrane solvent extraction.