抄録
New organophilic smectites were prepared by introducing quaternary ammonium cations containing polyoxyethylene (PEO) group into the interlayer of synthetic smectite (hectorite). The organophilic smectites formed a colloidally stable dispersion in polar organic solvents such as aprotic solvents and fatty alcohols to show high apparent viscosity. The stability of the dispersion of the organophilic smectites arose from the incorporation of the organic solvent molecules to the interlayer gallery of the organophilic smectites. The incorporation of the organic solvent molecules was caused by solvation to oxyethylene (EO) groups and hydroxyl groups in the guest cation and by affinity for the interlayer matrix. In the case of organophilic smectite dispersion in ethanol, the apparent viscosity was enhanced up to several times by the addition of water to the system. Maximal apparent viscosity was obtained at 10 wt.% of water content, where the dispersed particle size was markedly reduced. Consequently these phenomena can be accounted for by the role of water as polar activator in the organophilic smectite dispersion.
