Layered solid particles as self-assembled films

Surface hydrophobization of clay minerals (kaolinite, illite, montmorillonite) and CaAl double hydroxide by alkyl chains (n(c)=12-16) was studied. Clay minerals are hydrophobized by cationic surfactants, while in the case of LDHs anionic surfactants are used as hydrophobizing agents. Quantitative information on hydrophobicity was obtained from adsorption isotherms. Wetting properties of hydrophobic products were characterized by heats of immersion measured in organic solvents. Those among hydrophobic layer silicates which are not wetted by water form self-assembled solid films on the surface of water. The compressibility of these was by studied by a Langmuir balance. The orientation and thickness of clay mineral layers applied to a glass surface were studied using X-ray diffraction and surface plasmon spectroscopy.