Solubilization of a water-insoluble dye. II
Solubilization of a water-insoluble dye. II
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水不溶性染料的溶解。
DOI：
10.1021/j100870a041
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发表时间：
1967
期刊：
影响因子：
--
通讯作者：
H. Schott
中科院分区：
文献类型：
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作者：
H. Schott
先前描述的通过染料增溶测定数均胶束分子量（mmw）的方法3是基于增溶极限为每个胶束一个橙子OT分子的事实。这已经用癸烷磺酸钠（SDS 03）、十二烷基硫酸盐（SDS）和两种C12环氧乙烷（EO）缩合物建立。该方法被扩展到具有较大烃核的非离子洗涤剂胶束和阳离子洗涤剂。光散射结果表明，壬基酚（EO）30和十二烷基三甲基溴化铵（DTAB）的增溶量与染料相同，而C18（EO）18和氯化十六烷基吡啶（CPyC）的增溶量则增加了3倍，表明后两种洗涤剂在饱和时每胶束增溶3个染料分子。因此，染料增溶不是测定mmw的绝对方法。它可用于显示作为增溶的柔性链杂质或添加的电解质浓度的函数的mmw的相对变化，并提供最低可能的mmw。光散射法测得的离子型去污剂的分子量分别是染料溶解法测得的分子量的1.00和3.00倍。通过光散射确定的离子洗涤剂的毫米波明显降低，随着加入的电解质的量的减少，变得更小，在DTAB的情况下，比通过染料增溶确定的毫米波。由于减少添加电解质的量要么没有影响离子型洗涤剂的毫米波确定染料增溶或引起一个小的增加，重新检查的解释高电荷胶束的光散射理论似乎是为了。发现与一个溶解的染料分子相关的胶束烃核中的碳原子数按以下顺序减少：SDS 〇 3、SDS、DTAB、CPyC、C12（EO）16、C12（EO）28、C18（EO）18、壬基苯酚（EO）30。这也是极性头部基团的大小增加的顺序，表明后者越大，胶束的堆积越松散，其增溶能力越大。
A method for determiningnumber-average micellar molecular weights (mmw) by dye solubilization previously described3 was based on the fact that the solubilization limit was one molecule of Orange OT per micelle. This had been established with sodium decane-sulfonate (SDS03), dodecyl sulfate (SDS), and two Ci2 ethylene oxide (EO) condensates. This method was extended to micelles of nonionic detergents with larger hydrocarbon cores and to cationic detergents. Light scattering gave the same mmw as dye solubiliza-tion for nonylphenol (EO) 3o and dodecyltrimethylammonium bromide (DTAB), but tripled the mmw for Ci8 (EO) 18 and cetylpyridinium chloride (CPyC), indicating that the latter two detergentssolubilized three dye molecules/micelle at saturation. Dye solubilization is therefore not an absolute method for determining mmw. It can be used to show rela-tive changes of mmw as a function of solubilized, flexible-chain impurities or concentration of added electrolytes and provides the lowest possible mmw. Mmw of ionic detergents determined by light scattering were 1.00 or 3.00 timesthe mmw determined by dye solu-bilization in the presence of swamping electrolyte. The mmw of the ionic detergents determined by light scattering apparently decreased with decreasing amounts of added electrolyte, becoming smaller, in the case of DTAB, than the mmw determined by dye solubilization. Since decreasing amountsof added electrolyte either had no effect on the mmw of ionic detergents determined by dye solubilization or caused a small increase, a reexamination of the interpretation of light scattering theory for highly charged micelles seems in order. The number of carbon atoms in the micellar hydrocarbon core associated with one solubilized dye molecule was found to decrease in the order: SDS03, SDS, DTAB, CPyC, Ci2 (EO) i6, Ci2 (EO) 28, Ci8 (EO) i8, nonylphenol (EO) 30. This is also the order of increasing size of the polar head groups, indicating that the larger the latter, the more loosely packed are the micelles and the greater their solubilizing power.