New method makes patterned polymer films

Abstract

From the ACS meeting Ultrathin multilayer polymer films with potentially useful electronic and optical properties have moved a big step closer to practical applications thanks to a new procedure that makes the molecules form ordered patterns on selected areas of a surface. Previously, thin films of polyions—polymers with ionic repeating units—have been constructed in a number of laboratories by sequentially adsorbing layers of polyanions and polycations. But that so-called layer-by-layer technique leads to substrates with uniformly coated surfaces. The new method also uses alternating sheets of positively and negatively charged polymers. But now, by pretreating certain regions of a surface with one substance and the remaining areas with another, polyion films can be coaxed to form intricate patterns. Paula T. Hammond, assistant professor of chemical engineering at Massachusetts Institute of Technology, demonstrated the agility of her research group's film-growth procedure by coating gold surfaces with num...