ELECTROCHEMICAL AND THERMAL-BEHAVIOR OF CALCIUM-SELECTIVE MEMBRANES

An ion-selective membrane based on a polyimide polymeric matrix plasti cized with diethylene glycol dibenzoate and containing calcium synthet ic ionophores was used to obtain a potentiometric Ca2+ sensor. It give s a linear response over the pCa range 1-5 with a slope of 27.4 mV (pC a)(-1). The sensor can be used for the pH range 3-8.5. The calcium-sel ective membranes were characterized in terms of their surface morpholo gy and the structural parameter, the glass transition temperature. The ac impedance and FTIR analysis of the polyimide-based polymeric membr ane were also studied.