Hydrophobic polyethylene membrane for use in venting, degassing, and membrane distillation processes

Abstract

Described is a polyethylene membrane and in particular an ultra-high molecular weight polyethylene membrane that provides a high air permeability and is hydrophobic. The membranes have small pores andare suitable for sterilization by exposure to gamma radiation. The membranes can be made by methods that involve one or more of stretching the membrane and grafting hydrophobic monomers onto the membrane surface. A perfluorinated monomer, such as perfluoro-n-octyl acrylate, can be grafted to one or more surfaces of the membrane. The membranes have a high flow rate compared to unstretched or ungrafted membranes.

Description

[0001] Cross References to Related Applications [0002] This application claims the benefit of U.S. Provisional Application No. 62 / 310,378, filed March 18, 2016, which is hereby incorporated by reference in its entirety. Background technique [0003] Hydrophobic membranes are used in a variety of processes including venting, degassing and thin film distillation. [0004] Venting is performed in various manufacturing processes, including pharmaceutical manufacturing, to maintain a sterile environment in bioreactors. In general, the venting operation allows gases to be vented from a chamber (eg, a reaction chamber) while preventing water and pathogens (eg, bacteria, viruses, and fungi) from entering the chamber. In this sense, the membrane acts as a filter. Vent devices are well known in the art, such as those described in US Patent Nos. 8,852,324 and 8,430,114, and hydrophobic membranes are often a component of these and similar devices. [0005] For each of the three proc...

AI Technical Summary

Problems solved by technology

For example, polytetrafluoroethylene (PTFE) membranes are hydrophobic and allow high air permeability, but cannot be sterilized by gamma radiation

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