摘要
本文采用圆二色法研究了KCNS、NH_4CNS、硫脲、脲等化学增感剂(或助剂)对照相明胶的圆二色性光谱(以下简称为圆二色性)的影响,根据圆二色性的数据,来推断这些试剂对照相明胶的多级结构的影响。实验结果表明:这些试剂对明胶的圆二色性的影响是很强烈的,不同试剂不仅影响的程度不一样,而且影响的方式也不尽相同。比如:对明胶的240nm附近的负槽圆二色性的影响,在KCNS、脲的浓度的增大过程中圆二色性先是减小,经过一个最低值,然后又增加;在NH_4CNS的浓度增大过程中,圆二色性一直是增大的;在硫脲浓度增大的过程中,圆二色性却是迅速减小的,很快就减小到零。不管上述助剂各自对明胶的圆二色性影响怎样,但它们都有一个共同点,就是:改变或部分改变了明胶的多级结构。
The effect of some photographic additives, such as potassium thiocyanate, ammonium thio-cyanate, thiourea and urea on the multiple structure formation of photographic gelatin was investigated by circular dichroism (CD) method. The experimental results showed that the above-mentioned additives have a very strong influence on the CD of photographic gelatin, but they differ from each other in extent and manner. In the case of potassium thiocyanate and urea, with the increase of their amount, CD value first deceases gradually, through a minimum, finally increases again. In the case of thiourea, with the increase in amount the CD value decreases very fast, and finally approaches zero. In contrary to thiourea, ammonium thiocyanate exhibits a monotomic increasing tendency of CD value. All these different effects were attributed to the two contradictory factors: one decreasing CD by the additives and the other increasing CD by foreign Cotton Effect.
出处
《感光科学与光化学》
CSCD
1989年第4期1-5,共5页
Photographic Science and Photochemistry
关键词
明胶
助剂
多级结构
圆二色光谱法
photographic gelatin, additive, multiple structure, circular dichroism
