Conductive Polymer Functionalization by Click Chemistry

Click chemistry is used to obtain new conductive polymer films based on poly(3,4-ethylenedioxythiophene) (PEDOT) from a new azide functional monomer. Postpolymerization, 1,3-dipolar cycloadditions in DMF, using a catalyst system of CuSO4 and sodium ascorbate, and different alkynes are performed to functionalize films of PEDOT-N3 and copolymers prepared from EDOT-N3 and 3,4-ethylenedioxythiophene (EDOT). This approach enables new functionalities on PEDOT that could otherwise not withstand the polymerization conditions. Reactions on the thin polymer films have been optimized using an alkynated fluorophore, with reaction times of ∼20 h. The applicability of the method is illustrated by coupling of two other alkynes: a short chain fluorocarbon and a MPEG 5000 to the conductive polymer; this alters the advancing water contact angle of the surface by +20° and −20°/−25°, respectively. The targeted chemical surface modifications have been verified by X-ray photoelectron spectroscopy analysis.