Patterned polyfluorene surfaces by functionalization of nanoimprinted polymeric features.

A new procedure is described for surface grafting polymer brushes by step-growth polymerization from initiator-embedded polymeric thin films and micron- and nanometer-scale patterns. An imprint lithographic process, nanocontact molding, was used to prepare thin patterned cross-linked polyacrylate network films on silicon wafers that incorporated 4-bromostyrene in the networks. These networks present reactive 4-bromophenyl functionality at the surface that act as attachment sites for the subsequent Ni(0)- mediated step-growth condensation polymerization of 2,7-dibromo-9,9-dihexylfluorene The step-growth polymerization medium consisted of 2,7-dibromo-9,9-dihexylfluorene, Ni(0)-catalyst, and bipyridine in a toluene/dimethylformamide solvent mixture.