CaWO4核／卤化银壳光敏微晶的制备及性能研究

用于感光材料的卤化银微晶合成技术近二十年来取得了很大进展，合成出了诸如Ｔ－颗粒、核壳乳剂和外延复合颗粒等，使感光材料的性能日趋优异．但由于感光化学反应（如化学增感、光谱增感、潜影形成及显影过程等）基本上都发生在微晶的表面，而微晶核内部的卤化银却未发生...

STUDY ON THE PREPARATION AND PROPERTY OF LIGHT-SENSITIVE CaWO 4 CORE/AgX SHELL MICROCRYSTAL EMULSION

A new kind of light-sensitive CaWO 4 core/AgX shell microcrystal emulsion was first synthesized. The outer structures of CaWO 4 core/AgX shell microcrystal emulsion were observed by TEM and SEM, and the photographic properties of the emulsions were tested with X-ray and white light exposure. The results show that photographic property of the emulsion is obviously affected by AgNO 3 displacement percentage, time of KBr displacement and pBr value in displacement process. The thickness of AgX shell on the CaWO 4 core is about 10-15% of the microcrystal diameter. Since CaWO 4 core can absorb X-ray to emit fluorescence to expose the AgX shelled on the surface of CaWO 4 core from internal direction, therefore, the sensitivity of these heterophase microcrystals, comparing with the common cubic AgBr emulsion in the same condition under X-ray and white light exposure, is increased, and is ten and sixteen times higher than that of cubic AgBr emulsion. In a word ,these results show that CaWO 4 core/AgX shell microcrystal emulsion obviously has overwhelmingly advantages over common AgBr emulsion,can largely save valuable Ag, and is a promising information-recording material.