Insights on Adsorptive Property of Thermally Treated Smectite (Dioctahedral)

ABSTRACT The use of clay in the field of mineral materials is directly impacted by its thermal stability and changes in microstructure and properties following heat and other treatments. Therefore, it is crucial to investigate how clay's composition and structure are changed with time or how its surface characteristics are changed because of heat treatment. In the current work, the effect of heat treatment on the adsorptive property of smectite clay under various conditions like initial polymer concentration and its molar mass, pH, and temperature variation has been investigated. Various techniques like X‐ray fluorescence spectrometry, thermal analysis, X‐ray diffraction, infrared spectroscopy, and scanning electron microscopy were used for the phase analysis and the structural features of the heat‐treated clay analysis. It was observed that the specific surface area of smectite gradually dropped as the preheating temperature was increased, and the phase composition and structure underwent significant changes. When clay is heated over 423 K, the adsorbed gases and water are forced off the surface, increasing the amount of free active sites, and smectite's adsorption potential was increased. By raising the polymer's initial concentration and molecular mass, the extent of adsorption was increased whereas it was decreased with the increase in pH. However, in the case of temperature, the adsorption was first increased and then decreased with the increase in temperature indicating a change in the chemical composition of the clay and hence the surface area.