Proton-vacancy-conducting polymers based on anion-grafted ormosils synthesized via sol-gel process

ABSTRACT A novel basic proton conducting polymer (so-called proton-vacancy conducting polymer) has beensynthesized. It is based on the copolymerization via the sol-gel process of sulfonamide-containinggroups, partially deprotonated, and an internal plasticizer (POE segments). All the organic groups areattached to trialkoxysilanes which, through the hydrolysis-condensation process, lead to a silica- based backbone. The flexible films obtained are homogeneous and transparent. Maximumconductivities are obrved with 15% of the sulfonamide groups deprotonated by the organic base and 10% of 2000 M POE plasticizer. The conductivity values are 2 10-7 Q4-cm-1 at 30°C and 10-5-1cm-1 at about 84°C. The polymers are thermically stable up to 220°C and their electrochemicalstability range is close to 2V. 1. INTRODUCTION There is a demand for proton conducting polymers to be used in all-solid state electrochemical devices. One foreseen application is as electrolytes in electrochromic windows. The transmission oflight through these windows may be controled by the application of a potential to an electrochromicmaterial (W, Ni, Mn or V oxides and/or hydroxides) which undergoes a colour change as a result ofthe reversible insertion of cations, in particular protons.The ideal polymer must respond to several criteria. One of the main concerns is to obtain systemscombining good filmogenic properties with chemical and electrochemical stability and adherence to