Chemical and Materials Engineering, University of Nevada, Reno, Reno, Nevada 89557, USA.
J Phys Chem B. 2011 Mar 31;115(12):2979-87. doi: 10.1021/jp109202f. Epub 2011 Mar 8.
We use molecular dynamics (MD) and dynamic light scattering (DLS) measurements to analyze the size of reverse micellar structures in the AOT-water-isooctane system at different water-to-surfactant ratios at ambient temperature and pressure. We find good qualitative agreement for the size and morphology behavior of the reverse micelle structures between molecular dynamics calculations and DLS measurements; however, the average values for the reverse micelle size distributions are systematically larger for the DLS measurements. The latter tends to capture the average hydrodynamic size of the structures based on self-diffusion rather than the average physical size as measured in MD simulations, explaining the systematic deviations observed. The combination of MD with DLS allows a better interpretation of the experimental results, in particular for conditions where the structures are nonspherical, commonly observed at lower water-to-surfactant ratios. We also present and analyze the effect of zirconyl chloride on the micellar size distributions in this system. These type of salts are common for reverse micellar synthesis processes. We find that zirconyl chloride affects significantly the size distributions.
我们使用分子动力学（MD）和动态光散射（DLS）测量来分析在环境温度和压力下不同水与表面活性剂比的 AOT-水-异辛烷体系中反向胶束结构的大小。我们发现分子动力学计算和 DLS 测量之间对于反向胶束结构的大小和形态行为有很好的定性一致性；然而，DLS 测量的反向胶束尺寸分布的平均值系统上较大。后者倾向于根据自扩散来捕获结构的平均流体力学尺寸，而不是 MD 模拟中测量的平均物理尺寸，这解释了观察到的系统偏差。将 MD 与 DLS 相结合，可以更好地解释实验结果，特别是对于结构非球形的情况，这在较低的水与表面活性剂比下很常见。我们还介绍并分析了在该体系中氯化氧锆对胶束尺寸分布的影响。这类盐常用于反向胶束合成过程。我们发现氯化氧锆显著影响了尺寸分布。
