Organoclays prepared from montmorillonites with different cation exchange capacity and surfactant configuration

Organically modified montmorillonites ('organo-montmorillonites') have attracted a great deal of interest because of their wide applications in industry and environmental protection. We have synthesized organo-montrriorillonites using montmorillonites with different cation exchange capacities (CEC) and surfactants with different alkyl chain number and chain length. The organo-montmorillonites were characterized by X-ray diffraction (XRD) and differential thermogravimetry (DIG). The basal spacing of the organo-montmorillonites increased with surfactant loading, while the maximum basal spacing increased as the alkyl chain length of the surfactant increased. For the same surfactant, the maximum basal spacing of the organo-montmorillonites was little influenced by the CEC of the montmorillonite component. The level of surfactant loading required to reach the maximum basal spacing, however, strongly depended on the CEC. For a given alkyl chain length, the maximum basal spacing increased when the chain number increased from one to two. These findings are important to the preparation of low-cost organoclays for industrial applications. (C) 2009 Elsevier B.V. All rights reserved.