Solid State Physics Division , Bhabha Atomic Research Centre , Mumbai 400085 , India.
Homi Bhabha National Institute , Anushaktinagar, Mumbai 400094 , India.
Langmuir. 2019 Nov 5;35(44):14151-14172. doi: 10.1021/acs.langmuir.8b03596. Epub 2019 Feb 20.
A process in which a disordered system of pre-existing molecules generates an organized structure through specific, local interactions among the molecules themselves is termed molecular self-assembly. Micelles, microemulsions, and vesicles are examples of such self-assembled systems where amphiphilic molecules are involved. As the functional properties of these systems (such as wetting and emulsification, release of solubilized drugs, etc.) are dictated by the dynamic behavior of the surfactants at the molecular level, it is of immense interest to investigate these systems for the same. The dynamics in soft matter systems is quite complex, involving different time and length scales. We used a combination of neutron scattering and molecular dynamics simulation studies in probing the dynamic landscape in various self-assembled surfactant aggregates. Neutron scattering experiments were carried out using several spectrometers covering a wide dynamic range to probe motions on different time scales. The interaction between the surfactants can be varied by changing the molecular architecture, counterion concentration, temperature, and so forth. It is important to study the effect of these parameters on the dynamics of surfactants in these aggregates. We have carried out experiments on various ionic (anionic as well as cationic) micelles with varied counterion concentrations, vesicles, and lipid bilayers to unravel the complex dynamic features present in these systems. In this feature article, we will discuss some important results of our recent work on dynamics in these self-assembled surfactant aggregates.
通过分子自身之间的特定、局部相互作用，从无序的预存在分子系统中生成有序结构的过程称为分子自组装。胶束、微乳液和囊泡就是涉及两亲分子的此类自组装系统的示例。由于这些系统的功能特性（如润湿和乳化、溶解药物的释放等）取决于表面活性剂在分子水平上的动态行为，因此研究这些系统具有重要意义。软物质系统中的动力学非常复杂，涉及不同的时间和长度尺度。我们使用中子散射和分子动力学模拟研究相结合的方法，研究了各种自组装表面活性剂聚集体中的动态景观。我们使用覆盖广泛动态范围的几种光谱仪进行了中子散射实验，以探测不同时间尺度上的运动。通过改变分子结构、反离子浓度、温度等，可以改变表面活性剂之间的相互作用。研究这些参数对这些聚集体中表面活性剂动力学的影响非常重要。我们已经在各种离子（阴离子和阳离子）胶束、囊泡和脂质双层上进行了实验，以揭示这些系统中存在的复杂动态特征。在这篇专题文章中，我们将讨论我们最近在这些自组装表面活性剂聚集体动力学方面的一些重要研究结果。
