Will Sterlitech Track Etch filter membranes keep liquid behind the filter and let gases pass through?
A. The need for a gas vapor barrier requires the use of a hydrophobic filter with a water contact angle greater than 120°. If the contact angle is less than 120°, the filter will “bleed” through. The best filter material to use for a vapor barrier is made of PTFE (Teflon™). Most hydrophilic membranes generally have a contact angle that is less than 50°, and an hydrophobic membrane generally has a water contact angle greater than 120°. Raw polycarbonate film has a contact angle of approximately 70°, which is neither hydrophilic nor hydrophobic. It is for this reason that on most Sterlitech PCTE filter membranes we apply the wetting agent PVP. Sterlitech PETE filter membranes are naturally hydrophilic with a contact angle of approximately 40°, therefore, no wetting agent is added in the manufacturing process.
Related Questions
- I just received a box of Sterlitech Track-Etch filter membranes and I am trying to use them, but there is no liquid passing through. What is wrong?
- Will Sterlitech Track Etch filter membranes keep liquid behind the filter and let gases pass through?
- Do Sterlitech Track Etch filter membranes have any type of wetting agent on them?
