SYNTHESIS OF SILVER HALIDE TABULAR CRYSTALS : THE EFFECT OF THE SOLVENT ONTHE STABILITY OF 111 FACES

Silver bromide crystals have been precipitated by the double-jet method. The presence of polar aprotic solvents or protic solvents with a dissociation constant smaller than water increased the ratio and size of tabular crystals in the precipitate. This is explained considering that (111) surfaces are mainly composed of halide ions and therefore charged. Organic solvents reduce the solvation of the halide ions in the solution and stabilize the surface charge. A high ionic strength greatly favored the ratio of tabular crystals and enhanced tabular growth probably by helping the formation of the double electrical layer on the charged (111) faces.