HYDROPHILIC PTFE MEMBRANE

摘要

The present invention provides a microporous membrane comprising a polytetrafluoroethylene microporous substrate, wherein the membrane has a critical wetting surface tension of at least about 70 dynes/cm (about 70 mN/m) after exposure to 170 .degree.C for 3 minutes in air and after exposure to an aqueous 40% KOH solution for 10 days, and preferably also after exposure to an aqueous 30% H2SO4 solution and/or aqueous 30% HNO3 solution for 10 days. The present inventive membrane preferably comprises a polytetrafluoroethylene microporous substrate and a crosslinked vinyl pyridine monomer which is bonded to the substrate. The present invention also provides a methods of preparing and using such a microporous membrane, as well as a filter element incorporating such a microporous membrane within a housing.