Colloidal single crystals of silica spheres in the presence of simple- and poly-electrolytes, and ionic detergents.

Colloidal single crystals of silica spheres (103 nm in diameter) are formed in the presence of various kinds of salts 1 simple electrolytes, i.e., sodium chloride, calcium chloride and lanthanum chloride, 2 polyelectrolytes such as 3-6 type ionen polymer (polybrene), poly- N-ethylpyridinium bromide, a copolymer of N-benzyl pyridinium chloride and N-hexadecyl pyridinium bromide, and sodium polyethylene sulfonate, and 3 cationic and anionic detergents, hexadecyltrimethylammonium bromide and sodium dodecylsulfate. Shape and size of their single crystals, phase diagram, and the relationship between the two parameters among the critical concentration of melting, conductance and pH of the crystal-like suspensions have been studied. Colloidal single crystals of positively charged spheres have been formed in this study by the method of the charge reversal of spheres through the strong adsorption of cationic polyelectrolytes onto the anionic silica spheres. [ABSTRACT FROM AUTHOR]