Ernest John Perry

Effect of adsorbed substances of high molecular weight on the growth of silver halide crystals

Abstract A study of the effect of adsorbed substances of high molecular weight on the crystal growth of silver bromide containing a minor amount of silver iodide has shown that, in addition to two factors previously postulated by other workers as contributing to coalescence during crystal growth, namely, the presence of trace quantities of “growth promoters” and the degradative destruction of the adsorbed protective colloid layer, another factor must also be considered, namely, the nature of the protective colloid layer. Depending on the type of protective layer formed, there may be wide variations in the relative contributions of coalescence ripening and of Ostwald ripening to crystal growth. The nature of the adsorbed protective layer has a profound effect not only on the ease of crystal growth but also on the morphology of the crystals obtained.