Grafting polythiophene on polyethylene surfaces

Polythiophene (PT) was grafted on PE film using three reaction steps. First, PE films were brominated in the gas phase, yielding PE-Br; second, a substitution reaction of PE-Br with 2-thiophene thiolate anion gave the thiophene-functionalized PE; finally PT was grafted on the PE surface using chemical oxidative polymerization to give PE-PT. The polymerization was carried out in a suspension solution of anhydrous FeCl3 in CHCl3, yielding a reddish PE-PT film after dedoping with ethanol. ATR-FTIR shows that the PT was grafted on PE in the 2,5-position. SEM imaging revealed islands of PT on the PE film. AFM analysis found the thickness of islands to be in the range of 120-145 nm. The conductivity of these thin films was in the range of 10(-6)Scm(-1), a significant increase from the value ofsimilar to10(-14)Scm(-1) measured for PE film. (C) 2003 Society of Chemical Industry.