AgBrⅠ核壳乳剂的还原敏化与硫加金敏化的协同增感效应  

Cooperative Sensitization by Reduction and Chemical Sensitizations in AgBrⅠ Core-Shell Emulsions

作　　者：智欣[1] 史瑶[1] 曹静[1] 夏培杰[1] 

机构地区：[1]中国科学院理化技术研究所,北京100101

出　　处：《感光科学与光化学》2004年第5期350-356,共7页Photographic Science and Photochemistry

基　　金：国家重点自然科学基金资助项目(20033010).

摘　　要：使用微机控制的双注仪和二次乳化方法制备了一系列在AgBrⅠ核内进行不同程度还原增感的溴碘化银/溴化银核壳乳剂.对这些乳剂感光性能的研究表明:1)颗粒内部经还原敏化或Ag2掺杂的乳剂表现出明显的增感效应,颗粒内碘离子的存在并不影响Ag2的增感作用;2)在对乳剂进行了颗粒表面的硫加金增感以后,在一定的DMAB用量下,观察到显著的颗粒内部还原增感和表面硫加金增感的协同增感效应,使乳剂的感光度有了成倍的增长.以上协同增感效应的结果再次说明,颗粒内部的还原敏化中心与颗粒表面的硫加金敏化中心具有两种不同的增感机理,前者捕获空穴,后者捕获电子,两者都有利于提高潜影的形成效率.A series of cubic AgBrⅠ core-AgBr shell emulsions with different amounts of DMAB used for producing Ag_2 (R center) in the core were prepared by using a double-jet apparatus controlled by a microcomputer.The results from sensitometric measurements of these emulsions show that the emulsions doped by Ag_2 in the AgBrⅠ core exhibited a significant increase in sensitivities and the existence of I^- in the core-shell grains did not influence the sensitization of the internal Ag_2; and that these core-shell emulsions after surface sensitization by sulfur-plus-gold exhibited a remarkable cooperative sensitization,i.e.their sensitivities were much higher than that of the controlled one which was not doped with Ag_2 in the core.These results reconfirmed two kinds of different sensitization mechanisms,i.e.via trapping holes by the internal Ag_2 centers and concentration of electrons by sulfur-plus-gold sensitizing centers.Taking advantage to both mechanisms,a cooperative sensitization could be realized to improve the efficiency of latent image formation.

关 键 词：空穴—电子转换 AgBrⅠ核壳乳剂 Ag2掺杂 S+Au增感 协同增感 

分 类 号：TQ57[化学工程—精细化工]