Re-examination of the Aggregation Theory on Lightfastness

研究了高活性单氯三嗪基活性染料i -活性红120在不同盐浓度下对纤维素的吸附及在纤维素中的扩散行为。前者可以用Donnan膜平衡模型结合纤维素相和溶液相的电中性条件来描述，后者可以用孔模型结合扩散/吸附理论来描述。测定了染料在纤维素上的吸附，并证实了吸附可以类似地描述，尽管固定阴离子基团的影响显然是深远的。在吸附和扩散行为中没有发现支持聚集理论的证据。从染料潜在性能的角度分析了10种一氯三嗪活性染料在不同环境条件下对棉织物和纤维素膜的褪色行为。浓度对染色膜褪色行为的依赖可以用滤光剂效应来解释，但也有一些例外，其中具有高光敏性的染料在深染中比在浅染中表现出更大或相似的褪色。大多数染料表现出两步退色行为，即开始退色，随后退色较小。染料的氧化和/或还原性褪色首先取决于染料的化学结构，其次取决于环境条件。这些结果根本不支持关于耐光性的聚集理论。

The adsorption of C.I.Reactive Red 120, a monochlorotriazinyl reactive dye with high substantivity, on cellulose, and the diffusion behavior in cellulose were measured over a wide range of salt concentration. The former could be described by Donnan membrane equilibrium model combined with the electroneutrality conditions in both the cellulose and solution phases, while the latter by pore model combined with diffusion/adsorption theory. The adsorption of the dye on cellulose reactively-dyed previously was measured and was confirmed that the adsorption could be similarly described, although the effects of fixed anionic groups were apparently profound. There found no trace of proof that supported the aggregation theory in the adsorption and diffusion behavior.The fading behavior of ten monochlorotriazinyl reactive dyes on cotton fabrics and cellulose films under various environmental conditions was analyzed from the viewpoint of potential properties of dyes used. The concentration dependence on the fading behavior of dyed films could be explained by the filter effect with some exceptions, where dyes with high photosensitivity showed larger or similar fading in deep dyeings than that in the paler dyeings. Most dyes showed two step fading behavior, i.e., initial and then smaller subsequent fading. Their oxidative and/or reductive fading occurred depending firstly upon the chemical structure of dyes and secondarily upon the environmental conditions. These results do not support at all the aggregation theory on lightfastness.