Partially sulfonated ethylene-vinyl alcohol copolymer as new substrate for 3,4-ethylenedioxythiophene vapor phase polymerization

A new conducting composite polymer film is obtained by vapor phase polymerization of 3,4-ethylenedioxythiophene (EDOT) on a biocompatible polyanion derived from the partial sulfonation (32%) of statistical ethylene vinyl alcohol copolymer (EVAL32). EVALS32 and the oxidant (iron(III) p-toluenesulfonate, [PTS]) are contemporaneously spin coated from a methanol/water solution on glass slide. EVALS32-PTS-coated glass slides are exposed to EDOT vapors, and the polymerization is followed by Vis-NIR spectroscopy. We observed that PEDOT slowly grows into the bulk of EVALS32 matrix. Thanks to the sulfonic groups of the polyanion acting as doping agents, a highly conjugate p-doped EVALS32-PEDOT composite film with a good conductivity (1.6 × 102 S cm-1), transparency, and stability in water is obtained. The EVALS32-PEDOT film seems an ideal candidate for the preparation of organic devices to be applied in electronics, biosensor, or actuation technology. © 2014 Wiley Periodicals, Inc.