Flexibility of elongated sodium dodecyl sulfate micelles in aqueous sodium chloride: A small-angle neutron scattering study
Flexibility of elongated sodium dodecyl sulfate micelles in aqueous sodium chloride: A small-angle neutron scattering study
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DOI：
10.1021/la0006216
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发表时间：
2000-12-26
期刊：
影响因子：
3.9
通讯作者：
Butler, PD
中科院分区：
文献类型：
--
作者：
Magid, LJ;Li, Z;Butler, PD
使用小角中子散射在 45 摄氏度下研究了含有细长十二烷基硫酸钠 (SDS) 胶束的盐水溶液。在 1-2 M 范围内的 NaCl 浓度下，散射数据与半柔性而非刚性棒状胶束一致，并且该结论与之前使用小角度散射对 SDS 胶束的研究一致。然而，到目前为止，胶束柔韧性（即持久长度，特别是作为离子强度的函数）的定量测定尚未可用。通过在适合该长度尺度的散射矢量范围内进行测量，并将胶束间相互作用的影响纳入拟合方案中，可以准确地确定持久长度。讨论了将值划分为本征分量和静电分量，并将结果与高柔性阴离子聚电解质聚苯乙烯磺酸钠的数据进行比较。将柔性 SDS 胶束的一维弯曲模量与 SDS 双层的类似二维弯曲模量进行比较。
Aqueous salt solutions containing elongated micelles of sodium dodecyl sulfate (SDS) have been studied at 45 degreesC using small-angle neutron scattering. At NaCl concentrations in the 1-2 M range, the scattering data are consistent with semiflexible rather than rigid rodlike micelles, and this conclusion is consistent with previous studies of SDS micelles using small-angle scattering. However, until now quantitative determinations of micellar flexibility, that is, of persistence lengths, especially as a function of ionic strength, have not been available. By making measurements in the range of scattering vectors appropriate for this length scale and by incorporating the effect of intermicellar interactions into the fitting protocol, it has been possible to determine persistence lengths accurately. Partitioning of the values into intrinsic and electrostatic components is discussed, and the results are compared with data for the highly flexible anionic polyelectrolyte sodium polystyrenesulfonate. The one-dimensional bending moduli for the flexible SDS micelles are compared to the analogous two-dimensional bending moduli for SDS bilayers.