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本文利用X射线光电子能谱法和X射线衍射分析,研究了双注法高感乳剂乳化过程中,碘离子的引入时刻对于乳剂颗粒内碘离子分布情况的影响。结果表明,一般说来,碘离子引入得愈早,则其出现在颗粒表面的可能性愈小;引入得愈晚,其位置愈靠近颗粒的表面。但是,早期引入碘离子同时,还有另一种效应,即倾向于使碘离子在体系中均匀分布,从而使其出现在颗粒表面的概率增大。有若干事实说明,这种“均化”效果可能是早期形成的碘化银或碘溴化银晶体在乳化过程中进行重结晶而引起的。在所有情况下,颗粒表面上均发现一层极薄的富碘层,其原因之一可能是碘离子在颗粒表面的富集可减少碘溴化银晶格的畸变。
In this paper, X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) were used to study the influence of iodine ion introduction time on the distribution of iodide in emulsion particles. The results show that, in general, the earlier the iodine ions are introduced, the less likely they are to appear on the particle surface; the sooner they are introduced, the closer their positions are to the particle’s surface. However, the earlier introduction of iodide ion has the other effect that it tends to distribute the iodide ions evenly in the system, so that the probability of its appearance on the particle surface increases. There are several facts that this “homogenization” effect may be caused by the early formation of silver iodide or silver iodobromide crystals during the emulsification process. In all cases, a very thin iodine-rich layer was found on the surface of the particles. One of the possible reasons for this may be that the iodine ion enrichment on the particle surface can reduce the distortion of the silver iodobromide crystal lattice.