Self-strengthened conducting polymer hydrogels

Conducting polymer hydrogels of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS) with self-strengthening functions have been synthesized via a facile one-step procedure. The enhanced mechanical toughness, directly established in the materials in their formation process, results from the effective transfer of the local stress between the two components of PEDOT and PSS, which is closely related to the homogeneity of the microstructure and the phase structure. The experimental conditions for the fabrication of the hydrogels have been optimized, and samples prepared with suitable reagent concentrations can sustain a stress in the order of megapascals and a strain higher than 90%. The electrical conductivity of the hydrogels, in the order of 10(-2)S/cm, is demonstrated to be determined by the surface composition and the compactness of the samples. The contribution of this work lies in not only the invention of a new type of conducting polymer hydrogels with outstanding mechanical properties, but also the creation of a novel method to achieve facile preparation of multifunctional mechanically strong hydrogels through the combination of suitable components into proper structures. (C) 2010 Elsevier B.V. All rights reserved.