Dec 05, 2018 · The polytetrafluoroethylene (PTFE) membrane is an inlet membrane, a hydrophobic membrane filter, which is treated with ethanol or isopropanol to become a hydrophilic membrane filter. The hydrophobic membrane cannot be naturally wetted, and the hydrophilic membrane can be naturally wetted. Polytetrafluoroethylene (PTFE) membranes are resistant