Spontaneous nucleation of monodisperse silver halide particles from homogeneous gelatin solution II: silver bromide

The spontaneous nucleation process of monodispersed AgBr particles by gradu al release of silver ions from a Ag+-gelatin complex was studied on the bas is of the fundamental theory and analytical procedures for a AgCl system in the preceding report in this volume. The nucleation mechanism is basically the same as the AgCl system, in which the nucleation of the stable nuclei is governed by the growth of the generated stable nuclei and the final part icle number n(infinity) is determined by the equation, n(infinity) = Q(o)V( M)/(upsilon)over dot, where Q(o) is the rate of increasing concentration of solute, V-m is the molar volume of the solid, and (upsilon)over dot is the volumic growth rate of a stable nucleus during the nucleation period. Howe ver, the final particle size in diameter was much smaller by a factor of 1/ 6 and the nucleation time was about 30 times longer than those in the AgCl system. This is mainly due to the much smaller (upsilon)over dot in the AgB r system as a result of the lower solubility of AgBr. (C) 2000 Elsevier Sci ence B.V. All rights reserved.