Effects of solvent treatment and high-pressure homogenization process on dispersion properties of palygorskite

Dispersion of natural palygorskite in distilled water, methanol, ethanol, isopropanol, dimethyl formamide, and dimethyl sulfoxide was carried out using high-pressure homogenization. The effects of solvent parameters on the microstructure, morphology and colloidal properties of palygorskite were investigated in detail. Elemental analysis, infrared spectroscopy (IR) and thermogravimetric analysis (TGA) confirmed that some solvent molecules were encapsulated within the tunnels of palygorskite. The efficiency of the homogenization process to disperse palygorskite aggregates was closely correlated to the solvent parameters, particularly solvent vapor pressure and viscosity. A well disaggregated palygorskite was obtained after dispersing in dimethyl sulfoxide. It was also confirmed that colloidal stability and suspension viscosity were affected by the solvent nature. A more stable suspension with higher viscosity of 2364 mPa s was obtained by dispersing palygorskite in isopropanol. (C) 2012 Elsevier B.V. All rights reserved.