Mono- and Multilayers of Oligoethylene Oxide-Modified Poly(3,4-ethylenedioxythiophene) on ITO and Glass Surfaces

Dichloromethane-soluble poly(3,4-ethylenedioxythiophene)s modified with oligoethylene oxide chains of different lengths (PEDT−EO and PEDT−PEO) were produced by anodic coupling. PEDT−EO solutions were used to produce mono- and multilayer films on ITO−glass electrodes and float glass sheets. Layer-by-layer alternation of doped PEDT−EO with poly(p-styrene sulfonate) (PSS) or doped poly(3,4-ethylenedioxythiophene) sulfonate produced electroactive and robust multilayered surfaces with low surface resistivity (5 × 105 Ω/□ for a PEDT−EO/PSS 10-bilayer). Analogous multilayers could be built from doped PEDT−EO and polyammonium polycations. Doped PEDT−EO forms with PSS the first reported electrostatically bound polyionic multilayers in which the positive charge is delocalized over a polythiophene backbone.