Whatman* PTFE (Type WTP) Membranes

Chemically stable and inert, suitable for use at temperatures up to 145°C and naturally hydrophobic. For applications involving aggressive organic solvents, strong acids and alkalis. Backed with a polypropylene support web to facilitate handling. One of the major applications for the PTFE (Type WTP) filter is the clarification of corrosives, solvents and aggressive fluids. This includes the important requirement in HPLC analysis for sample filtration where any solid particles can cause permanent damage to the column. The 0.5 µm pore size is normally used. Air and gas sterilization make use of the hydrophobic characteristics of PTFE membranes and their ability to stop aqueous aerosols. Usual pore sizes are 0.2 µm and 0.5 µm. Sterile venting of vacuum manifolds, fermentation vessels and sterile filtrate tanks and containers utilize PTFE 0.2 µm membranes.