PTFE membrane is a thin, highly porous film that behaves as an absolute retentive membrane. Their inherently hydrophobic nature make PTFE membranes ideal for applications such as filtering gases, aqueous aerosols, protecting vacuum pumps, or sterile venting fermentation tanks. PTFE is inert to most chemically aggressive solvents, strong acids and bases and can be used for solvent clarification and HPLC sample prep.
PTFE membranes are available unsupported and supported. PTFE membranes with a laminated polypropylene web support to one side offers improved handling characteristics. Chemical and thermal limitations are imposed by the backing.
One of the important characteristics in membrane selection is whether you want a membrane that is Hydrophobic or Hydrophilic. Here we’ll define these terms, as well as provide some examples of membrane materials and applications for both types. Hydrophilic literally means “water loving.” Hydrophilic membranes will attract water, and in the process push away other molecules in order to allow water access to the membrane. This keeps contaminants away from the membrane allowing it stay clean and functioning for a longer period of time. Because of this trait hydrophilic membranes are especially well suited for medical applications and biological assays. Hydrophobic on the other hand, literally means “afraid of water.”
These membranes will block the passage of water and are commonly used for applications involving separation of water from other materials, such as venting gases. Here is a helpful table that compares membrane materials and common uses for hydrophilic and hydrophobic properties:
Post time: Mar-10-2020