Hybrids of Nafion (R) and silica were prepared from solution, growing the inorganic phase by hydrolysis/condensation of alkoxy silanes. Using tetraethoxysilane (TEOS) as the inorganic precursor, transparent and rigid films were obtained. Substituting part of the TEOS (20 wt% substitution) by 1,1,3,3 tetramethyl-1,3-diethoxydisiloxane (TMDES) more flexible films were obtained. These films were translucent and showed a phase segregation which was clearly observed by transmission electron microscopy. The ionic conductivity of the hybrids was measured by electrochemical impedance spectroscopy using two stainless steel electrodes, a frequency range of 0.1 to 10(5) Hz, and temperatures from 25 to 100 degrees C. Samples were also characterized by modulated differential scanning calorimetry. (C) 1998 Elsevier Science S.A. All rights reserved.44541671394
