Advantec Unlaminated PTFE Hydrophilic Membranes. Advantec's line of unsupported, hydrophilic, pure PTFE membranes are ideally suited for use in HPLC separations and other applications involving mixtures of aqueous and organic solvents. Read More. Choosing PTFE as a filtration medium ensures maximum chemical compatibility, wide-ranging thermal/pH resistance, and high flow rates/minimal aqueous extractables.