Formation of Silver Bromide Crystals in Double-Jet Precipitation


Formation of Silver Bromide Crystals in Double-Jet Precipitation

Ingo H. Leubner, Ramesh Jagannathan, and Jong S. Wey, Photographic Science and Engineering, 24: 268-272 (1980)

Note: This is the historically first publication on the balanced nucleation and growth (BNG) model for nucleation control of crystallizations.

Correction: In this paper, the number of crystals formed was normalized to the initial reactor volume (reaction volume). Subsequent publications and experiments show that this normalization is in disagreement with the model, which predicts that in a homogeneously mixed system the number of crystals is independent of the reaction volume.

Following work showed, that the correlation between crystal number and solubility is linear for AgBr and AgCl, and that an erroneous data point forced the present super-linear correlation.

Ingo H. Leubner

In this paper, the effects studied are the initial reaction addition rate, solubility, and temperature on the formation of stable silver bromide (AgBr) crystals in balanced double-jet precipitations. The experimental results show that the number or stable crystals increases with increasing reactant addition rate, and decreases with increasing solubility and temperature. The dependence of the stable crystal number on these precipitation variables, however, did not exhibit the simple proportionality predicted from an equation given by Klein and Moisar.

 The present theoretical model explains the results based on a dynamic mass balance and a growth mechanism, which includes bulk diffusion and the Gibbs-Thomson effect (Ostwald ripening). This paper gives the derivation of this model, and its application to the interpretation of the experimental results.