Effect of thermal transformation on the structural and electrical properties of dodecylalkylammonium intercalated sodium-montmorillonite

Abstract

In the present investigation Dodecylalkylammonium intercalated montmorillonite (DDA-MMT) has been synthesized by intercalating Dodecylalkylammonium into the interlayer spaces of Na-montmorillonite (Na-MMT) by ion exchange reaction at 80°C. Thermal transformation of DDA-MMT has been investigated by Thermogravimetric analysis and Differential Thermogravimetric analysis. X-ray Diffraction analysis and Scanning Electron Microscopy and Fourier Transform Infrared analysis of pre-heat-treated DDA-MMT samples were performed to understand the thermal transformation mechanism. Different microstructural parameters such as crystallite size, r.m.s. strain (<e2>1/2) and layer disorder parameters such as variation of interlayer spacing (g), proportion of planes affected by variability defect () have been calculated using X-ray line profile analysis of DDA-MMT pre-heat-treated at 30, 80, 120, 200, 300, 400 and 500°C. The value of basal spacing (d001), FWHM, number of silicate layers stacked to form individual crystallite (N) have also been used for understanding the thermal transformation of DDA-MMT. Alternating Current electrical properties of DDA-MMT at room temperature and pre-heat-treated at different temperatures have also been investigated.