Is the catalytic active silver surface really growing in the course of development?

摘要

The photographic development is commonly considered as an autocatalytic process due to the growing developed silver surface. The "parallel" development of grains has been shown to increase the silver mass as a simple linear function of time. Its constant term corresponds to the initial soaking period. Since all the emulsion grains start developing nearly the same time, the linear kinetics stands constant for every individual grain until its undeveloped mass is completely exhausted. After the smallest grains are completely developed, the linearity gets distorted. The classic exponential knetics correspond only to the grains each of them had wholly developed for its after-induction time being much less than the difference of induction periods of simultancously developing grains. Some data inducated the constant rate of siler filament growth and a particular catalytic activity of their ends are discussed. Latent image (LI) nanoclusters as stabilized in statu nascendi by the metal-polymer interactions suggest themselves to be the invariable active areas.