Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia.
MTA-SZTE Lendület Biocolloids Research Group, Interdisciplinary Excellence Center, Department of Physical Chemistry and Materials Science, University of Szeged, H-6720 Szeged, Hungary.
J Colloid Interface Sci. 2021 Jul 15;594:150-159. doi: 10.1016/j.jcis.2021.02.113. Epub 2021 Mar 9.
By combining the experimental small- and wide-angle x-ray scattering (SWAXS) method with molecular dynamics simulations and the theoretical 'complemented-system approach' it is possible to obtain detailed information about the intra- and inter-molecular structure and dynamics of the solvation and hydration of the surfactant in organic and mixed solvents, e.g., of the nonionic surfactant Brij 35 (CE) in alcohols and aqueous alcohol-rich ternary systems. This first application of the complemented-system approach to the surfactant system will promote the use of this powerful methodology that is based on experimental and calculated SWAXS data in studies of colloidal systems. By applying high-performance computing systems, such an approach is readily available for studies in the colloidal domain.
SWAXS experiments and MD simulations were performed for binary Brij 35/alcohol and ternary Brij 35/water/alcohol systems with ethanol, n-butanol and n-hexanol as the organic solvent component at 25 °C.
We confirmed the presence of solvated Brij 35 monomers in the studied organic media, revealed their preferential hydration and discussed their structural and dynamic features at the intra- and inter-molecular levels. Anisotropic effective surfactant molecular conformations were found. The influence of the hydrophobicity of the organic solvent on the hydration phenomena of surfactant molecules was explained.
通过将实验小角和广角 X 射线散射（SWAXS）方法与分子动力学模拟以及理论的“互补体系方法”相结合，可以获得有关表面活性剂在有机溶剂和混合溶剂中溶剂化和水合的分子内和分子间结构和动力学的详细信息，例如非离子表面活性剂 Brij 35（CE）在醇和含水醇丰富的三元体系中的溶剂化和水合。这种互补体系方法首次应用于表面活性剂体系，将促进基于实验和计算 SWAXS 数据的这种强大方法在胶体体系研究中的应用。通过应用高性能计算系统，这种方法很容易用于胶体领域的研究。
在 25°C 下，对二元 Brij 35/醇和三元 Brij 35/水/醇体系进行了 SWAXS 实验和 MD 模拟，其中乙醇、正丁醇和正己醇作为有机溶剂成分。
我们证实了在研究的有机溶剂中存在溶剂化的 Brij 35 单体，揭示了它们的优先水合，并讨论了它们在分子内和分子间水平的结构和动态特征。发现了各向异性的有效表面活性剂分子构象。解释了有机溶剂疏水性对表面活性剂分子水合现象的影响。
