Dispersion characteristics of illite clay minerals by polymer grafting

We described a polymer grafting technique for surface treatment of illite clay minerals and examined the dispersion-improving behavior of surface-treated illite in organic solvents. For polymer grafting on illite surfaces, illite was first treated with silane agents to provide primary amine groups on its surfaces and was subsequently reacted with polyethylene-graft-maleic anhydride for PE grafting on illite surfaces. PE-grafted illite was characterized using Fourier transform near-infrared spectroscopy, solid-state nuclear magnetic resonance spectroscopy, powder X-ray diffraction, and thermogravimetric analysis. Dispersion behaviors of PE-grafted illite were examined in distilled water and xylene. PE-grafted illite formed precipitates in distilled water, whereas native hydrophilic illite exhibited good dispersion stability. In contrast, in xylene, PE-grafted illite exhibited excellent dispersion behavior, but native illite was precipitated. The excellent dispersion behavior of PE-grated illite in xylene was also confirmed by monitoring scattered light intensities, which were estimated by dynamic light scattering analyses.