ABSTRACT

Self-assembled systems based on low-molecular-weight gelators (LMWGs) and micelle-forming surfactants are stabilized by non-covalent and non-interfering interactions. The simultaneous self-assembly of LMWGs and surfactants in a solution could lead to the formation of fibrillar networks with encapsulated surfactant micelles. In this study, the gelation properties of amino-acid-derived low-molecular-weight bis-urea compounds in water, various organic solvents, and surfactant solutions, including anionic surfactants sodium dodecyl sulfate and dodecylbenzene sulfonic acid, cationic surfactant cetrimonium bromide, and nonionic surfactants polysorbate 80 and octyl-β-d-glucopyranoside, were investigated. In the presence of surfactants, the nature of the linker of the bis-urea compounds influences the aggregation between gelator molecules. Compounds with cyclic and aromatic linkers effectively form gels at surfactant concentrations above a critical micelle concentration (CMC). The different fiber morphologies observed for surfactant gels based on imaging analysis suggest that the structure of the bis-urea compounds influences self-assembly. Rheological measurements revealed the solid-like nature of the gels and their high thermal stability. The viscoelastic nature of the surfactant gels offers potential use in various commercial applications, including home care products.

摘要

基于低分子量胶凝剂 (LMWG) 和形成胶束的表面活性剂的自组装系统通过非共价和无干扰的相互作用来稳定。LMWG 和表面活性剂在溶液中同时自组装可能导致与封装的表面活性剂胶束形成纤维网络。在这项研究中，氨基酸衍生的低分子量双脲化合物在水、各种有机溶剂和表面活性剂溶液中的凝胶特性，包括阴离子表面活性剂十二烷基硫酸钠和十二烷基苯磺酸、阳离子表面活性剂西曲溴铵和非离子表面活性剂聚山梨酯80和辛基-β- d-吡喃葡萄糖苷，进行了研究。在表面活性剂存在下，双脲化合物的连接基的性质影响胶凝剂分子之间的聚集。具有环状和芳香族连接基的化合物在表面活性剂浓度高于临界胶束浓度 (CMC) 时有效形成凝胶。基于成像分析观察到的表面活性剂凝胶的不同纤维形态表明双脲化合物的结构影响自组装。流变学测量揭示了凝胶的类固体性质及其高热稳定性。表面活性剂凝胶的粘弹性性质提供了在各种商业应用中的潜在用途，包括家庭护理产品。