Combined kinetic and spectroscopic study of oxidation of azo dyes in surfactant solutions by hypochlorite
Combined kinetic and spectroscopic study of oxidation of azo dyes in surfactant solutions by hypochlorite
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DOI：
10.1016/s0143-7208(00)00051-6
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发表时间：
2000-09-01
影响因子：
4.5
通讯作者：
Gordon-Smith, T
中科院分区：
文献类型：
--
作者：
Oakes, J;Gratton, P;Gordon-Smith, T
用动力学、光谱和热力学相结合的方法研究了阳离子、阴离子和非离子表面活性剂对次氯酸盐氧化偶氮染料II的影响。在胶束或胶束下，阴离子或非离子表面活性剂(SDS或C12E5)的存在对氧化速率没有影响：这表明没有任何特定的染料-表面活性剂相互作用。另一方面，在胶束下和胶束区域观察到与阳离子表面活性剂的特殊相互作用。在染料II中加入CTAts后，其UV-Vis光谱强度降低，氧化速率降低。这归因于通过与磺酸盐基团的相互作用，与染料形成了稀有的可溶1：1络合物。DTAC与染料在亚胶束区域的结合导致氧化速率略有增加，这归因于小的、可溶的染料聚集体的分解。在胶束区域，有证据表明，染料进入了两种阳离子表面活性剂形成的胶束表面，在那里它们变得惰性，不能与次氯酸盐反应。(C)2000爱思唯尔科学有限公司。保留所有权利。
Combined kinetic, spectroscopic and thermodynamic investigations have been carried out to examine the influence of cationic, anionic and nonionic surfactants upon the oxidation of an azo dye, II, by hypochlorite. Oxidation rates were unaffected by the presence of anionic or nonionic surfactant (SDS or C12E5) either in micellar or submicellar regions: indicating the absence of any specific dye-surfactant interactions. On the other hand, specific interactions were observed with cationic surfactants, both in submicellar and micellar regions. Addition of CTAts to dye II produced a reduction in intensity of its UV-vis spectrum and caused oxidation rates to decrease. These are attributed to formation of a sparingly soluble 1:1 complex with the dye, via interactions with the sulfonate groups. Binding of DTAC to the dye in sub-micellar regions results in a slight enhancement in oxidation rates, which is attributed to break-up of small, soluble dye aggregates. In micellar regions, there was evidence that the dye becomes incorporated into the surface of micelles formed by both cationic surfactants, where they become inert to reaction with hypochlorite. (C) 2000 Elsevier Science Ltd. All rights reserved.