核壳乳剂的潜影分布和Sabatier效应的研究

本文制备了两种单分散八面体模型孔剂,一种是含碘10mol％的碘均匀分布碘溴化银乳剂,另一种是内核含碘20mol％的碘溴化银,外壳为溴化银的核壳乳剂。并对它们分别进行表面硫加金和硫加金加铱敏化。用简单腐蚀技术研究上述乳剂的内部影像空间分布的结果表明:随着表面敏化程度的增加,表面敏度逐渐增大;随着腐蚀的深入,内部敏度逐渐减少。核壳乳剂的表面和内部敏度均大于碘均匀分布颗粒乳剂。核壳乳剂的内部影像在颗粒內部先逐渐减少,在一定深度以后又逐渐上升,内部影像分布出现“低谷”,且“低谷”程度与表面敏化程度有关。Sabatier效应研究的结果表明:产生较明显的Sabatier效应的乳剂颗粒既要有足够的表面敏度,也要有足够的内部敏度,且两者要匹配。同时提出了产生Sabatier效应的机理。

THE DISTRIBUTION OF LATENT IMAGE AND SABATIER EFFECT IN CORE-SHELL EMULSION

The distribution of latent image and the Sabatier effect of two groups of monodisperse silver iodobromide emulsions were studied. The emulsions in one group were common monodisperse emulsions in which 10 mol% iodide was uniformly distributed within the grain, and the emulsions in the other group were core-shell emulsions of which the designed composition was 20 mol% iodide in the core and 0 mol% iodide in the shell. The total iodide contents of the grain in the two groups of emulsions were equal. Both groups of emulsions were chemically sensitized by sulfur plus gold and sulfur plus gold plus iridium, respectively. Simple etch method of partial dissolution and surface development was used to reveal the distribution of internal latent image. It is found that the surface sensitivity as well as the internal sensitivity of the core-shell emulsions are greater than that of the corresponding uniform silver iodo-bro-mide emulsions. It is noticed that there are reversals of internal image only in the core-shell emulsions. The study of the Sabatier effect combined with the determination of internal image distribution shows that an emulsion that shows good Sabatier effect should contain grains with enough surface as well as enough internal sensitivity centers, and they should be well matched.