Zhang Fan, Zhang Qun, Yang Jian, Zhou Yawen, Zhou Zhaohui, Wang Ce
State Key Laboratory of Enhanced Oil Recovery, Research Institute of Petroleum Exploration & Development Beijing 100083 PR China.
Beijing Technology and Business University Beijing 100048 PR China
RSC Adv. 2020 Jul 10;10(44):26102-26108. doi: 10.1039/d0ra03713c. eCollection 2020 Jul 9.
Interface dilational rheology is useful for understanding and exploring the role of interface phenomena. However, relatively few studies have been conducted on the interface dilational rheological properties of -acyl aromatic amino acid surfactants. Herein, surface tension and the dynamic interface tension and dilational rheological properties of three surfactants, namely, sodium -lauroyl phenylalaninate (SLP), sodium -lauroyl tyrosinate (SLTy), and sodium -lauroyl citrate (SLTr) were investigated. The results show that the order of critical micelle concentration, which includes the surface tension at the critical micelle concentration, minimum area per surfactant molecule, and interfacial tension, was SLTr < SLTy < SLP. At a low surfactant concentration, the three surfactants exhibited a low-viscosity interfacial elastic film at the -decane/water interface. The dilational modulus increased and the phase angle decreased with increase in frequency. However, the order of the dilational modulus was SLP < SLTy < SLTr, while the order of the phase angle change was SLTr < SLTy < SLP at the same frequency. With increase in surfactant concentration, the dilational modulus of SLP and SLTy increased and then decreased after a maximum value; however, the dilational modulus plot of SLTr demonstrated two maxima.
界面扩张流变学对于理解和探索界面现象的作用很有用。然而，关于酰基芳香族氨基酸表面活性剂的界面扩张流变性质的研究相对较少。在此，研究了三种表面活性剂，即月桂酰苯丙氨酸钠（SLP）、月桂酰酪氨酸钠（SLTy）和月桂酰柠檬酸钠（SLTr）的表面张力、动态界面张力和扩张流变性质。结果表明，临界胶束浓度的顺序，包括临界胶束浓度下的表面张力、每个表面活性剂分子的最小面积和界面张力，为SLTr < SLTy < SLP。在低表面活性剂浓度下，这三种表面活性剂在癸烷/水界面处表现出低粘度的界面弹性膜。随着频率增加，扩张模量增大而相角减小。然而，在相同频率下，扩张模量的顺序为SLP < SLTy < SLTr，而相角变化的顺序为SLTr < SLTy < SLP。随着表面活性剂浓度的增加，SLP和SLTy的扩张模量先增大，在达到最大值后减小；然而，SLTr的扩张模量图显示有两个最大值。
