外来杂质Fe^(3+)与照相明胶相互作用的研究

Study on the Interaction between Doped Ferric Ion and Photographic Gelatin

采用Ｘ射线光电子能谱和电子自族共振技术研究了外来杂质Ｆｅ(３＋)与照相明胶的相互作用。结果表明，明胶对外来的３价铁有很强的还原能力。不同的明胶对外来铁的还原容量不同，相对于惰胶中所允许的含铁量，这个还原容量是相当高的。超过这个容量后，外来的３价铁离子将部分保持原有价态而不被还原。在这个容量以内，外来的３价铁将全部被还原。还原后的铁以络合形态存在于明胶中，其微观配位化学环境与明胶中本身存在的铁的配住环境有所差异．外来Ｆｅ３＋的加入，不仅影响到明胶中泛醌自由基信号的自旋浓度，而且还影响到ＲＳ·自由基（ｇ＝２２４６，ｇ＝１．９３４）的产生和消退。

The interaction between doped ferric ion and photographic gelatin was investigated byXPS. ESR. The results show that gelatin has very strong reducing power for the added ferricion, but the reducing capacity is different for different gelatins. When the amount of the addedferric ions exceeds this capacity, some ferric ions will not be reduce and remain their originaltrivalence. When the added ferric ions are reduced, their chemical state in gelatin is different fromthat of the ferrum originally existing in gelatin. The density of outmost shell electron cloud ofthe former is less than that of the latter, i.e. the ligands that form complex with added ferrumare different from that with original ferrum. The reduction capacity is very high compared withthe admitted amount of ferrum in inert gelatin and varies in different gelatins. After reduced,the ferrem was coordinated by gelatin macromolecule and the coordination environment is different from the coordination environment of ferrum in undoped gelatin. The doped ferric ion notonly effect the spin concentration of Ubiquinone in gelatin, but also the production anddisappearance of RS. free radical (=2.246, g = 1.934). In gelatin E the addition of ferricions may cause monoelectron transfer of the ubiquinone radical.