Silver Clusters of Photographic Interest III. Formation of Reduction-Sensitization Centers in Emulsion Layers on Storage and Mechanism for Stabilization by TAI
Silver Clusters of Photographic Interest III. Formation of Reduction-Sensitization Centers in Emulsion Layers on Storage and Mechanism for Stabilization by TAI
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摄影兴趣的银簇 III。
DOI：
10.2352/j.imagingsci.technol.1998.42.4.art00012
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发表时间：
1998
影响因子：
1
通讯作者：
A. Matsunaga
中科院分区：
文献类型：
--
作者：
T. Tani;N. Muro;A. Matsunaga
将AgBr乳化层在70℃Ar气体中储存72h与相同乳剂还原增感后感光度的提高进行了比较，结果表明，在储存过程中，乳剂颗粒上形成了还原增感的R中心。通过紫外光电子能谱(UPS)测量，证实了明胶在储存过程中电子从明胶转移到AgBr颗粒形成R中心的驱动力，即明胶的费米能级高于AgBr.然而，对于储存时R中心的形成，有人提出电子转移是通过两电子过程进行的，而不是在AgBr颗粒中产生任何自由电子或任何单一的银原子。硫加金敏化颗粒在储存过程中形成了雾化中心和还原敏化中心。稳定剂4-羟基-6-甲基-1，3，3a-7-四氮杂环烷(TAI)抑制了硫增金增感AgBr乳剂在储存过程中的感光度增加和雾化。这为TAI稳定乳胶层的机理提供了证据，TAI通过阻止还原敏化中心的形成而抑制了贮藏过程中的感官变化。
Comparison of the increase in sensitivity of AgBr emulsion layers caused by their storage in Ar gas at 70°C for 72 h with that caused by reduction-sensitization of the same emulsions revealed that R centers of reduction-sensitization were formed on the emulsion grains during the storage. The driving force for the electron transfer from gelatin to AgBr grains on storage for formation of R centers was confirmed by ultraviolet photoelectron spectroscopy (UPS) measurement, whereby the Fermi level of gelatin was higher than that of AgBr. It was however proposed for the formation of R centers on storage that the electron transfer took place by a two-electron process without creating any free electron or any single silver atom in the AgBr grain. Fog centers as well as reduction-sensitization centers were formed on sulfur-plus-gold-sensitized grains during storage. A stabilizer 4-hydroxy-6-methyl-1,3,3a -7-tetraazaindene (TAI) depressed the sensitivity increase and fog formation in layers of sulfur-plus-gold-sensitized AgBr emulsions on storage. The observation provided evidence for the mechanism of stabilization of emulsion layers by TAI, according to which TAI depresses sensitometric change on storage by preventing formation of reduction-sensitization centers.