DC electrical conductivity of nano-composite polystyrene–titanium– arsenate membrane

Abstract

In continuation to our previous work with nano-composite polystyrene–titanium–arsenate (PS–Ti–As), we further extended the characterization by means of DSC, TEM and mercury porosimetry measurements. In addition to the extended characterization, we also investigated the DC electrical conductivity behaviour of the PS–Ti–As composite membrane under different time, temperature and electrolyte conditions. The conductivity of the membrane investigated in the temperature region of 30– 200 8C using a four-in-line probe DC measurement and in the semi-conductor region of 10 5– 10 3 S cm 1, found to obey the Arrhenius equation. From the time and temperature dependent conductivity studies on the HCl doped composite, it was observed that the conductivity increases with increase of temperature until 100 8C and further decreased with time during 120–160 8C, which can be attributed to the loss of HCl dopant molecules and blocking of the chemical reactions associated with the dopant. Further, we studied the stability of DC electrical conductivity retention in an oxidative environment by two slightly different techniques viz. isothermal and cyclic.