Multifunctional MF and UF Membranes Via Cationic Polymerization of Substituted Styrenes

Functionalization of MF and UF membranes imparts active properties to inherently passive materials.  New properties can include catalytic function, charge, and adsorptivity.  The large pore size of these membranes simplifies the addition of polymeric grafts in the porous structure.  The chemistry of added grafts determines the active properties of the multifunctional membrane.  In this paper we will discuss a highly versatile multifunctional membrane containing polystyrene based grafts.  Grafting chemistry is based on the living polymerization of substituted styrenes.

Cationic polymerization is a living polymerization.  This means that there is no termination reaction, and therefore growth is only limited by the availability of monomer.  When growing polymer grafts in-situ, this mechanism offers a unique opportunity to tailor the graft composition by cycling through a series of monomers.  A custom graft can be designed and crafted based on the needs of the process, be that separation or reaction.  This is of particular value when designing highly selective adsorption sites for membrane chromatography and affinity separations.  This paper will provide an overview of multifunctional membranes synthesized in this fashion, including applications to catalysis, adsorption, protein separation, and affinity separations.