Entegris, Inc.

Solvay Specialty Polymers Italy S.p.a.

Alketa Gjoka

Jieh-Hwa Shyu

Jad Ali Jaber

Jijun Ge

Alessandro Ghielmi

Claudio Oldani

Saksatha Ly

Ven Anantha Raman

Matthias Gebert

A polysulfone membrane is modified so that monomers are wafted onto the surface of the membrane. The polysulfone membranes can be grafted by contacting the membrane with a grafting solution and exposing the membrane to electromagnetic radiation, typically within the ultraviolet portion of the spectrum. The monomers that are grafted are typically anionic or cationic. The grafted membranes can be used for filtering impurities, such as positively and negatively charged particles, from a liquid. Anionic membranes provide improved filtration of negatively charged impurities, while cationic membranes provide improved filtration of positively charged impurities.

Grafted polysulfone membranes

A polysulfone membrane is modified so that monomers are grafted onto the surface of the membrane. The polysulfone membranes can be grafted by contacting the membrane with a grafting solution and exposing the membrane to electromagnetic radiation, typically within the ultraviolet portion of the spectrum. The monomers that are grafted are typically anionic or cationic. The grafted membranes can be used for filtering impurities, such as positively and negatively charged particles, from a liquid. Anionic membranes provide improved filtration of negatively charged impurities, while cationic membranes provide improved filtration of positively charged impurities.

Grafted, asymmetric, porous, ultra high molecular weight polyethylene membranes having a bubble point between about 5.38 bar (78 psi) and 11.03 bar (160 psi) are disclosed. Monomers are grafted to the porous polymeric membrane surfaces, the monomers having one or more of neutral groups or ion exchange groups grafted to one or more surfaces of the membrane. A combination of two photoinitiators can be used to graft the monomers to the asymmetric, porous, ultra high molecular weight membrane resulting in grafted microporous membranes that have water flow rates that are at least 50% of the water flow rate of an ungrafted, asymmetric, porous ultra high molecular weight polyethylene membrane. The grafted membrane also wets in water.

Grafted ultra high molecular weight polyethylene microporous membranes

Microporous membrane composites that are non-dewetting are disclosed. These microporous membrane composites are wet with solutions of methanol and water and are non-dewetting following autoclave treatment in water. The microporous membrane composites comprise a microporous membrane support that is coated with a crosslinked ionomer comprising hydrophilic groups. Compared to the microporous membrane support, the microporous membrane composite has a flow loss on average in isopropyl alcohol of less than 82%.

Non-dewetting porous membranes

Versions of the invention include compositions and methods for making them that include a polymeric porous membrane with one or more atmospheric pressure microwave plasma modified surfaces. The modified porous membrane is stable, non-dewetting, and retains its mechanical strength.

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Medford, MA, United States of America

Alketa Gjoka