Electrochemical models of photographic development - a review

✍ Scribed by M.R.V. Sahyun

• Publisher: Elsevier Science
• Year: 1978
• Tongue: English
• Weight: 632 KB
• Volume: 23
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(78)85065-8

✦ Synopsis

Abstracf

Electrochemical models for photographic development allow the selectivity of the process to the rationalized. In the case of physical development, the development nucleus obviates the excess surface free energy associated with addition of silver(O) to particles below a threshold size. This explanation is insufficient in the case of direct development, whereby the smallest stable latent images (ELI four atoms)can be exploited. A qualitative rationalization of selectivity in this case can be couched in terms of the Marcus theory of electron transfer ; thereby the presence of the latent image avoids the penalty of reorganization energy associated with Frenkel defect formation. An analogous model of physical development is possible, but less powerful than that based on the Kelvin equation, but is quantitative. Treatment of the continued enlargement of either the physical development nuclei or the latent image in a silver halide crystal as an electrode process yields kinetics consistent with experimental observations. lNTBODUCTlON