TAI对鱼明胶介质中AgBr/I超细颗粒的保护作用  

Protective Action of TAI on Ultra-fine AgBr/I Particles Formed in Aqueous Fish Gelatin Solution

作　　者：徐峰[1] 岳军[1] 董永平[1] 李晓光[1] 

机构地区：[1]中国科学技术大学材料科学与工程系,合肥230026

出　　处：《Chinese Journal of Chemical Physics》2005年第2期257-262,共6页化学物理学报（英文）

基　　金：ProjectsupportedbytheNorlandProductsInc. USA.

摘　　要：TAI(4-羟基-6-甲基-1,3,3a,7-四氮茚)可以显著影响鱼明胶介质中AgBr/I超细颗粒的生长.红外光谱测量显示,其特征NH伸缩振动带消失,表明通过形成N-Ag络合物, TAI吸附到AgBr/I超细颗粒表面上.紫外吸收光谱数据分析指出, TAI分子在AgBr/I超细颗粒上吸附状态与乳剂颗粒成熟过程有关,单位表面积最大吸附量及最高覆盖率均出现在物理成熟初期的5 min时,可以认为,此时TAI与Ag之间形成了最适合于吸附的空间网状结构,延长物理成熟时间, TAI在AgBr/I超细颗粒上的吸附逐渐趋于平衡状态,其单位面积吸附量及覆盖率基本不变,分别在1.3 μmol/m2和47%～49%水平.TEM观察此时AgBr/I超细颗粒的平均粒径与粒径分布也基本不再变化,最大平均粒径也出现在物理成熟5 min时.TAI存在下,乳剂颗粒的平均粒径及其生长速率均明显低于不含TAI的乳剂颗粒,表明TAI对在鱼明胶介质中生长的AgBr/I超细颗粒具有明显的保护作用.TAI (4-hydroxy-6-methyl-1,3,3a,7-tetraazaindene) significantly influences ultra-fine AgBr/I particle growth in aqueous fish gelatin. IR spectrum shows that the NH stretching vibration hand of TAI is absent in ultrafine AgBr/I particle/fish gelatin emulsion, indicating the formation of N-Ag bond and the adsorption to AgBr/I Particles. By the analysis of UV adsorption spectrum, it is shown that the amount and percentage coverage of TAI adsorbed to ultra-fine AgBr/I particle is related with the physical ripening process of emulsion. With ripening for 5min, the amount of TAI adsorbed per unit area of AgBr/I particle and percentage coverage of TAI on the particle surface reached maximum, which may be attributed to a suitable space structure of TAI-Ag compounds. As the ripening time was prolonged, the adsorption amount per unit area and percentage coverage of TAI adsorbed on the surface of ultra-fine AgBr/I particle showed a tendency to level off on the whole, i.e. 1.3 μ mol/m(2) and 47% ∼ 49%, respectively. By TEM observation, the largest average diameter of ultra-fine AgBr/I particles appeared after physical ripening for 5 min. No significant change of the average diameter and size distribution of the particles was observed when the ripening time was prolonged continuously. In the case of TAI addition, the average diameter and growth rate of ultra-fine AgBr/I particles in aqueous fish gelatin solution was obviously smaller than that without TAI addition, indicating TAI protection for ultra-fine AgBr/I particles in emulsion. Under cooperative action of TAI and fish gelatin, the average diameter and size distribution of ultra-fine AgBr/I particles hold relative stability.

关 键 词：AgBr/I 鱼明胶 TAI 透射电镜 紫外吸收光谱 红外吸收光谱 

分 类 号：TQ575.23[化学工程—精细化工]