Journal of Dispersion Science and Technology ( IF 2.2 ) Pub Date : 2021-01-19 , DOI: 10.1080/01932691.2020.1844736 Sana Ullah 1 , Pingping Zhang 1 , Yuzhao Wang 1 , Zhenghong Chen 1 , Ce Wang 1 , Changyao Liu 1 , Baocai Xu 1
Abstract
Amino acid surfactants have been applied to numerous areas of science and are often used in the presence of electrolytes. In this study, the interfacial rheological behaviors of potassium N-cocoyl glycinate (KCGl), an amino acid surfactant, with three kinds of electrolytes (KCl, CaCl2 and tetrabutylammonium bromide (TBABr)) have been investigated using the oscillating drop method. The interfacial tensions (IFTs) and dilational rheological parameters show that KCGl in conjunction with electrolytes has enhanced interfacial activity and stronger intermolecular interaction than pure KCGl, indicating that electrolytes contribute to denser molecular packing at the oil–aqueous interface. Interestingly, the butyl groups of TBA+ hinder closer arrangement of molecules at the interface, hindering KCGl ability to form a tightly packed layer compared with K+ and Ca2+ electrolytes. The relaxation processes, such as diffusion exchange of surfactant molecules between the aqueous phase and interface, are more probable to occur. Therefore, more viscoelastic films are formed in the presence of TBABr.
中文翻译:
电解质对N-椰油酰甘氨酸盐界面流变行为的影响
摘要
氨基酸表面活性剂已应用于许多科学领域,并经常在电解质存在下使用。在这项研究中,使用振荡滴落法研究了氨基酸表面活性剂N-椰子酰基甘氨酸钾(KCG1)与三种电解质(KCl,CaCl 2和四丁基溴化铵(TBABr))的界面流变行为。界面张力(IFTs)和膨胀流变参数表明,与纯KCG1相比,KCG1与电解质的结合具有增强的界面活性和更强的分子间相互作用,表明电解质有助于油水界面处更密集的分子堆积。有趣的是,TBA +的丁基与K +和Ca 2+电解质相比,阻碍了分子在界面处的更紧密排列,阻碍了KCG1形成紧密堆积层的能力。松弛过程,例如表面活性剂分子在水相和界面之间的扩散交换,更可能发生。因此,在TBABr的存在下形成更多的粘弹性膜。