Studies on thin film polymer electrolytes: application to sensors

Abstract

The development of solid polymer electrolytes has acquired great significance principally because of their potential applications in various electrochemical devices such as batteries, fuel cells, gas sensors, steam electrolyser, etc. Over the last few decades, a considerable amount of research work has been reported on solid polymer electrolytes due to the technological advantages, such as long self-life, extreme miniaturization, wide temperature range of operation and they can be prepared easily with low cost. These solids exhibit appreciable high ionic conductivities at their operating temperatures. These solids are also referred as “Fast Ion Conductors” (FIC) or “Solid electrolytes”, which are characterized by (a) Ionic bonding (b) High electrical conductivity (~ 10-1 to 10-3 S.cm-1) and (c) Ionic transport number ti ~1. So, these materials have to be promising because of their high value of ionic conductivity and possibility of preparing them in thin film form. In view of this, a great deal of interest has been paid to the study of ion transport and electrochemical behavior of various thin film polymer materials. Thin film solid polymeric materials are used mainly in fabrication of various implants and medical devices in the medical materials industry due to its desirable properties like light weight and modality. Besides, the chemical composition containing only carbon, hydrogen, oxygen, and nitrogen makes it posses better biocompatibility. In this electronic age, it is mandatory to use solid polymer electrolytes for different applications in science and technology. Polymer electrolytes can be shaped in the form of thin film, there by reducing the internal resistance leading to application as gas sensing material. Few reports are appeared on proton conducting polymer films and their application to gas sensors.