Clay surface modification with cationic surfactant and their thermal, morphological and crystal structure analysis

Abstract

The current work used ion exchange techniques to investigate the interactions of the cationic surfactant cetylpyridinium chloride (CPC) with naturally occurring clays like vermiculite (Vt), bentonite (Bent), and montmorillonite (Mmt). Characterization techniques such as X-ray diffraction (XRD), Fourier transform infra-red (FT-IR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and zeta sizer are used to confirm that the surfactant either intercalates in the interlayer region of clay minerals or interacts onto the surface due to electrostatic interaction during interaction. The end products of CPC interaction are referred to as organo clays. The intercalation of surfactant in the interlayer of clay minerals by substituting their interlayer ions was further supported by the XRD pattern in the cases of Montmorillonite and Bentonite, which showed an increase in basal spacing. The existence of two additional vibrational bands, asymmetric and symmetric stretching of the CPC's methylene group, indicated surface interaction between the surfactant and clay minerals in the FT-IR spectra. Following alteration, there was no discernible change in the morphology of the clay minerals. According to TEM pictures, the particle size of the organo clays was between 4 and 50 nm. The surface interaction of CPC with clay minerals was further validated by the notable shift in surface charge data obtained from the zeta sizer.