Composition-Dependent Thermal Stability and Water-Induced Self-Healing Behavior of Smectite/Waterborne Polymer Hybrid Film.

By casting an aqueous suspension containing a water-soluble polymer, polyvinylpyrrolidone, and a layered silicate, synthetic hectorite, on the solid substrate, films with varied interlayer expansion were obtained depending on the composition. The thermal stability, water resistance, water-induced self-healing behavior, and adhesion were examined to find their composition dependence, which is thought to be originated from the nanostructure variation. Polyvinylpyrrolidone was thermally stable up to 300 °C for the hybrid with the polymer/clay weight ratio of 0.

Adsorption-Induced Dye Stability of Cationic Dyes on Clay Nanosheets.

Rhodamine 6G (R6G) was adsorbed on smectite clays, a natural montmorillonite, a synthetic saponite, and synthetic hectorites, and the decolorization of the dyes upon visible light irradiation was examined for aqueous suspensions and cast films. Excellent dye stability was achieved when a natural montmorillonite was used. Apart from R6G, better photostability was also achieved when the tris(2,2'-bipyridine)ruthenium(II) complex was adsorbed on a natural montmorillonite.