Dispersion of palygorskite in ethanol–water mixtures via high-pressure homogenization: Microstructure and colloidal properties

The nanorods of natural palygorskite exist as aggregates or bundles. High-pressure homogenization technology can disaggregate effectively the bundles or aggregates of palygorskite in water. In order to further explore the effect of the dispersion medium on the dispersion efficiency, in this paper, palygorskite was dispersed in ethanol–water mixture with the aid of high-pressure homogenization. The effects of various ethanol/water ratios on the microstructure and colloidal properties of palygorskite were investigated. It was found that the dispersion efficiency of aggregates during the homogenization process was affected as increasing the ethanol/water ratio from 0:10 to 4:6. The introduction of ethanol into the aqueous suspension of palygorskite could weaken the van der Waals forces and hydrogen bonding interaction among rods, and a stable suspension with higher shear stress and shear modulus was obtained at the ethanol/water ratio of 6:4 (v/v).