甲酸盐在纳米AgBr／I粒子乳剂中的增感作用

分别以鱼明胶和骨明胶(惰胶)作为分散介质制备了两种不同形貌与粒径的纳米AgBr／I粒子乳剂．利用掺入作为正空穴捕获剂的甲酸盐，可以使本征感光度很低的纳米粒子乳剂的感光度有相当大的提高，显示甲酸盐具有很好的增感效果．对鱼明胶介质中制备的纳米AgBr／I粒子乳剂，甲酸盐掺杂方式不同其增感效果不一样．在乳剂颗粒中均匀掺杂增感效果最好，而趋向于近表面掺杂则增感效果降低，显示出甲酸盐掺杂的位置效应．籽晶掺杂后包壳的复合结构乳剂颗粒与均匀掺杂乳剂颗粒的增感效果近似．对鱼明胶介质中制备的掺杂甲酸盐的纳米AgBr／I粒子乳剂再进行硫增感或硫加金增感，乳剂感光度可进一步提高，表明甲酸盐掺杂与常规的硫增感或硫加金增感有很好的协同作用．

Sensitization of Formate in Nano-Sized AgBr/I Particle Emulsion

By fish gelatin or bovine gelatin as dispersion medium, two nano-sized AgBr/I particle emulsions with different morphology and size were prepared. Photosensitivities of two emulsions increased significantly by the addition of formate as positive hole scavenge dopant, showing formate effective sensitization. It was noted that various formate-doping methods resulted in different sensitized functions. Photosensitivity of the emulsion with homogeneous distribution of formate ions in nano-sized emulsion particle was higher than that of near surface distribution of formate ions in the particle, indicating formate-doping site effect. The multi-structural emulsion particles composed of formate doped core and pure silver halide shell demonstrated approximate photosensitivity as homogeneous formate doped emulsion particles. The addition of sulfur or sulfur-plus-gold into fomate doped nano-sized AgBr/I particle emulsion made photosensitivity further increased, which presented a synergetic effect of formate sensitization with conventional sulfur or sulfur-plus-gold sensitization.