Organics on Clays
The adsorption of organic molecules by hydrophobic and hydrophilic clay minerals is more strongly governed by structural aspects than previously assumed. In this review this structural dependence is illustrated (1) by methanol molecules on Li- and Ca-smectite, (2) the clustering of polar molecules (ethanol, formamide, dimethyl sulfoxide) in alkylammonium smectites and vermiculites, and (3) the adsorption of methanol-benzene mixtures by alkylpyridinium smectites. The reactions of clay minerals with small, but complicated organic compounds and with monomelic and polymeric anions have also been reported recently, such as interactions with paraquat, diquat, thionine, parathione, purines, pyrim-idines, nuclein bases, adenosine mono- and triphosphate, and chelated Co-complexes.
Interesting new results on polymer clay interactions have been reported for polyanion adsorption, e.g., polyacrylate and anionic Polyacrylamides, and behavior of smectites towards polycations is explained by the reactions with ionenes. The protein lysozyme can be intercalated by a disaggregation-reaggregation mechanism. An example of enzyme immobilization is the binding of glucose oxidase by sodium and hexadecyl trimethylammonium montmorillonite. Organic molecules of low and high molecular weight exert a large influence on rheological properties. This influence is illustrated by the effect of cationic and anionic surfactants on the viscosity of kaolinite dispersions and of polyvinyl alcohol on dispersions of sodium montmorillonite.
Figures & Tables
Proceedings of the International Clay Conference Denver, 1985
The papers included in this proceedings volume are representative of the research on clays being conducted in all parts of the world at the time of publication. Many of the subjects treated are controversial, and although some ideas expressed may not necessarily represent the views of the editors, the referees, or the publisher, they deserve to be brought to the attention of the international clay community.