Surface-initiated radical polymerization on porous silica

A novel chemical reaction to minimize termination reactions in radical polymerization is applied for the first time to the growth of thin polymer films on silica. A living polyacrylamide thin film is grown from a self-assembled benzyl chloride monolayer on silica gel using Cu(bpy)(2)Cl to control the radical population. The polymerization is sufficiently well controlled that films grown on nanoporous silica leave the pores intact, as shown by its ability to separate proteins by size exclusion. The living polyacrylamide film covers the silica surface uniformly, as shown by the highly efficient elution of lysozme, a strongly basic protein, at pH 4.7. The new chemistry for film growth enables polymers to be used to make new stationary phases on porous silica gel.