Abstract: Turbidimetry was used at 21℃ to measure the growth rate of AgBr crystals which were dispersed in the aqueous solution of sodium dodecyls sulphate (SDS), 3,4-dimethyl-1,2,4-triazo-le-5-thione (DMT) or cetyl trimethyl ammonium bromide (CTAB) at pBr₄ or pAg₄. The results indicated that the increase of the average crystal volume was not due to the coagulation of particles but involved in a process of recrystallization, i.e. Ostwald ripening. The addition of SDS (10^-5 mol·dm^-3) causes the acceleration of AgBr recrystallization in pAg₄ and the retardation of AgBr growth in pBr₄, whereas the addition of DMT has a great restraining effect on the AgBr growth and the addition of CTAB accelerates AgBr growth by adsorbed C⁺. The possible explanation of the above-mentioned phenomena in AgBr recrystallization was also discussed.

Key words: photographic chemistry, silver bromide, crystal-growth modifiers, cetyl tri-methyl ammonium bromide, sodium dodecyls sulphate