冠醚化合物在制备外延卤化银乳剂中的作用

自从冠醚于六十年代末问世以来^1,2],科学家们对它进行了大量的研究。它以遮盖力大,对金属离子络合性能好而著称于化学领域。在感光化学领域,它的主要应用在于对乳剂晶体的尺寸及分布产生影响,使之均一,且颗粒增大^3-6];作为调变剂,促进外延乳剂晶体的生长^7-8];提高乳剂的感光性能^5,9-11]。

THE FUNCTION OF CROWN ETHER AS A GROWTH MODI-FIER IN THE PREPARATION OF EPITAXIAL SILVER HALIDE EMULSION

The action of dibenzo-18-crown-6 as a growth modifier in the preparation of epitaxial silver halide emulsion and its complexation to silver halide crystallite were studied.Because of the complexation, the active sites (edges and corners) of the silver halide grains are partially dissolved and new crystal faces (100) come into sight, so that the crystallite could take a more stable state.Because the dibenzo-18-crown-6 can increase the solubility of silver bromide, the grain size of the emulsion prepared under its presence is larger than that prepared under normal condition.With the complexation of dibenzo-18-crown-6 to the silver bromide crystallites, several active defects were produced on their edges and corners, and when the epitaxial growth was taken place, the epitaxial components were first deposited on the active defects.