A Field Dependent 2H Nuclear Magnetic Relaxation Study of the Aggregation Behavior in Micellar Solutions of CTAB and SDS
A Field Dependent 2H Nuclear Magnetic Relaxation Study of the Aggregation Behavior in Micellar Solutions of CTAB and SDS
复制标题
CTAB 和 SDS 胶束溶液中聚集行为的场相关 2H 核磁弛豫研究
DOI：
10.1021/j100079a025
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Molly Ginley
中科院分区：
文献类型：
--
作者：
Maria Toernblom;U. Henriksson;Molly Ginley
用2H核磁驰豫方法研究了十六烷基三甲基溴化铵(CTAB)在水中的胶束溶液和十二烷基硫酸钠(SDS)在0.22M氯化钠中的胶束溶液。最近由Halle(/.)建立了聚集态表面活性剂分子动力学的完整理论模型。化学。太棒了。1991、94、3150。)应用后，就可以根据聚集体的大小和形状来评估松弛数据。在一个简单的溶液多分散性模型中确定了平均聚集数。对于这两个体系，都发现在远低于第二CMC的浓度下形成了非球形聚集体。在第二临界胶束浓度以上，聚集体呈棒状，平均聚集数随浓度的增加而迅速增加。
Micellar solutions of cetyltrimethylammonium bromide (CTAB) in water and of sodium dodecyl sulfate (SDS) in 0.22 m NaCl were investigated with field dependent 2H nuclear magnetic relaxation. The full theoretical model for the molecular dynamics of aggregated surfactant molecules recently developed by Halle (/. Chem. Phys. 1991, 94, 3150.) was applied, making it possible to evaluate therelaxation data in terms of aggregate sizes and shapes. Average aggregation numbers were determined within a simple model for the polydispersity of the solutions. For both systems it was found that nonspherical aggregates were formed at concentrations well below the second cmc. Above the second cmc, the aggregates were found to be rod-shaped and the average aggregation number increased rapidlywith the concentration.