抄録
Montmorillonite was treated with a small amount of aliphatic alkyltrialkoxysilanes with different lengths of alkyl chains in dry air. The alkyltrialkoxysilane molecules were chemically bonded on to the edge surface of the silicate layers of montmorillonite. Rheological behavior of the aqueous suspensions of the products was investigated as a function of the number of carbon atoms in the alkyl chain. The viscosity of the suspensions considerably increased with the increase of the number of carbon atoms in the alkyl chain and the type of flow changed to a typical Bingham flow, whereas the original montmorillonite suspension exhibited a pseudoplastic or socalled shear-thinning flow. The Robinson's viscosity equation and the intrinsic viscosity model of an oblate ellipsoid given by Kuhn and Kuhn (Güven, 1992) were applied to the viscosity data of the aqueous suspensions for the explanation of the particle characteristics of montmorillonite treated with n-hexyltrimethoxysilane. An appreciable increase of the intrinsic viscosity of the montmorillonite treated with n-hexyltrimethoxysilane suggested the formation of a lamellar structure of developed edge-to-edge arrangement of particles, due to the hydrophobic bonding of the alkyl chains on the edge surface. The product is expected to be useful industrially as a rheology-controlling agent for various aqueous fluid products.
