Rheo-NMR phenomena of wormlike micelles
Rheo-NMR phenomena of wormlike micelles
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DOI：
10.1039/b600978f
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发表时间：
2006-10-07
期刊：
影响因子：
3.4
通讯作者：
Callaghan, P. T.
中科院分区：
文献类型：
--
作者：
Lopez-Gonzalez, M. R.;Holmes, W. M.;Callaghan, P. T.
利用流变学和核磁共振波谱/测速技术相结合的方法，采用时间平均和实时测量的方法，证明了在(H2O)-H-1或(H2O)-H-2中，当胶束体系的摩尔比为10%w/v十六烷基氯化铵和水杨酸钠摩尔比2：1时，在(H2O)-H-1或(H2O)-H-2中存在剪切带波动。这些剪切带波动不仅与在流变学测量中观察到的剪切应力波动一致，而且与在H-1-核磁共振实验中观察到的两亲链的约束分数(f(C))变化的波动相一致。利用位于蠕虫状胶束内部的氚探针分子(正癸烷)的H-2-核磁共振波谱，直接测量了剪切诱导的向列相相变。
Using a combination of rheology and nuclear magnetic resonance (NMR) spectroscopy/velocimetry we demonstrate the existence of shear banding fluctuations under Couette flow of the micellar system 10% w/v cetylpyridinium chloride and sodium salicylate (CPyCl-NaSal) molar ratio 2 : 1 in 0.5 M NaCl in either (H2O)-H-1 or (H2O)-H-2, using both time-averaged and real-time measurements. These shear banding fluctuations are consistent not only with the shear stress fluctuations observed in rheological measurements but also with fluctuations in the change of the constrained fraction of the amphiphile chain (Delta f(c)) observed in H-1-NMR spectroscopy experiments. Using H-2-NMR spectroscopy on a deuterated probe molecule (n-decane) located in the wormlike micellar interior, direct measurement of the shear-induced nematic phase transition is reported.