Effects of interactions on the formation of mixed micelles of 1,2-diheptanoyl-sn-glycero-3-phosphocholine with sodium dodecyl sulfate and dodecyltrimethylammonium bromide.
Effects of interactions on the formation of mixed micelles of 1,2-diheptanoyl-sn-glycero-3-phosphocholine with sodium dodecyl sulfate and dodecyltrimethylammonium bromide.
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DOI：
10.1016/j.jcis.2004.08.071
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发表时间：
2005-02
影响因子：
9.9
通讯作者：
C. Vautier-Giongo;M. Bakshi;Jasmeet Singh;R. Ranganathan;J. Hajdu;B. Bales
中科院分区：
文献类型：
--
作者：
C. Vautier-Giongo;M. Bakshi;Jasmeet Singh;R. Ranganathan;J. Hajdu;B. Bales
通过荧光和核磁共振测量研究了磷脂 1,2-二庚酰基-sn-甘油-3-磷酸胆碱 (DHPC) 与十二烷基硫酸钠 (SDS) 或十二烷基三甲基溴化铵 (DTAB) 在水溶液中的混合胶束以及各组分之间相互作用的影响。应用正则溶液理论（RST）分析了混合胶束中芘荧光光谱确定的实验临界胶束浓度值。 DHPC + SDS 和DHPC + DTAB 混合物的相互作用参数(β12) 均为负值，前一种情况下该值更负。两个体系的负β12值意味着磷脂和两种离子表面活性剂之间的相互作用本质上是有吸引力的，在DHPC + SDS的情况下更强烈。相互作用参数 β12 随混合物的组成而变化，表明堆积的变化。两个系统的质子核磁共振位移有很大不同，并且也随组成而变化。根据混合胶束中静电和空间相互作用的致密程度对这些实验确定的化学位移的解释支持了荧光 cmc 实验得出的结论。
Mixed micelles of the phospholipid 1,2-diheptanoyl-sn-glycero-3-phosphocholine (DHPC) with sodium dodecyl sulfate (SDS) or dodecyltrimethylammonium bromide (DTAB) in aqueous solutions and the effects of interactions between the components were studied by fluorescence and NMR measurements. The regular solution theory (RST) was applied to analyze the experimental critical micelle concentration values determined from the fluorescence spectra of pyrene in the mixed micelles. Negative values for the interaction parameter (β12) were obtained for both DHPC + SDS and DHPC + DTAB mixtures, with the value being more negative in the former case. The negative β12values for the two systems imply that the interaction between the phospholipid and the two ionic surfactants is attractive in nature, being more intense in the case of DHPC + SDS. The interaction parameter, β12, varies with composition of the mixtures indicating changes in packing. The proton NMR shifts are quite different for the two systems and also vary with composition. An interpretation of these experimentally determined chemical shifts in terms of the degree of compactness attributed to electrostatic and steric interactions in the mixed micelle supports the conclusions derived from the fluorescence cmc experiments.