PTFE membrane is manufactured in a unique way where polytetrafluorethylene (PTFE) is expanded both uniaxially and biaxially. The resultant membrane is thin, highly porous, and behaves as an absolute retentive membrane.
Unsupported PTFE membranes offer maximum chemical and pH resistance to a broad range of aqueous and organic solvents making it an optimal membrane to sterilize and clarify strong acids and many solvents incompatible with other membranes. Since PTFE is inherently hydrophobic these membranes are used to sterilize gases and trap aqueous aerosols. When used in venting applications, they allow the gases to pass freely while blocking aqueous liquids thereby protecting pumps and critical samples.