Ceramic Membrane Modification by Graft Polymerization
Yoram Cohen, Robert Castro and Harold Monbouquette
This research project focuses on the development of novel ceramic-supported polymer (CSP)
membranes. The CSP membrane is a composite ceramic-supported polymeric membrane where
the surface chemistry is imparted by a terminally anchored polymer surface layer. The synthesis of
the silica-PVP membrane required careful control of the polymer surface graft yield and the length
of the resulting terminally anchored surface chains. This is achieved by careful surface activation
and control of the graft polymerization reaction. To date, a prototype CSP silica membrane based
on highly hydrophilic polyvinylpyrrolidone (PVP) was prepared. The silica-PVP membrane was
evaluated for the treatment of an oil-in-water emulsion in a cross-flow filtration mode. In this
system, the hydrophilic PVP brush layer expands due to the affinity of the polymer for water (i.e.,
it is completely water soluble) while preferentially allowing the passage of water over oil. The
resulting membrane produced a permeate with a lower oil concentration relative to the unmodified
membrane. At the same time, the flux decline, which was observed with the unmodified
membrane, was significantly reduced with the silica-PVP membrane.
Reference:
Castro, R., H. Monbouquette, and Y. Cohen and R. Castro, "The Permeability of Surface
Modified Porous Silica Membranes," Journal Membrane Science, 84, 151-160 (1993).