【摘要】 利用界面扩张流变技术,研究了两性咪唑类离子液体表面活性剂1-磺丙基-3-十二烷基咪唑内盐(C12im SP)的界面聚集行为,探讨传统表面活性剂十二烷基硫酸钠(SDS)对C12im SP界面聚集行为的影响机制。结果表明,少量SDS的加入可以填补界面上疏松的C12im SP分子间的空位,界面上形成表面活性剂混合吸附膜,界面张力显著降低;提高SDS的浓度,其分子从体相向界面层的扩散交换占优势,界面层分子逐渐达到饱和吸附,此后体系中有混合胶束形成。体相胶束中富集的SDS分子对C12im SP分子的"收纳"作用及进一步的"挽留"作用,加之C12im SP分子本身相对较大的空间位阻效应导致界面上的C12im SP分子一旦通过扩散作用被交换至体相,其很难再回复到表面层,即界面膜以SDS分子为主。通过调节体系中SDS的含量,可以实现对混合体系SDS/C12im SP/Na Cl(0.1 mol/L)界面聚集行为的调控,进而实现对界面膜性质的调控。更多还原

【Abstract】 The interfacial dilational rheological method was used to study the interfacial aggregation behavior of zwitterionic imidazole surfactant 3-( 1-dodecyl-3-imidazolio) propanesulfonate( C12 im SP) solutions. The effect and mechanism of traditional surfactant sodium dodecyl sulfate( SDS) on the aggregation behavior of C12 im SP at air / water interface were explored. The results have shown that the SDS molecules tend to fill the vacancy among C12 im SP molecules when the C12 im SP molecules arrange loosely at interface,and mixedadsorption films formed by SDS and C12 im SP spread on the air / water interface,correspondingly,the interfacial tension decrease dramatically. With the increase of SDS concentration,the diffusion exchange of molecules from bulk phase to interface is predominant and the interfacial layer reaches saturation adsorption gradually.Thereafter,the mixed micelles appear in the system. The "acceptance"and the further "detainment"of the rich SDS molecules in micelles to C12 im SP molecules as well as the larger steric hindrance of C12 im SP themselves lead to the C12 im SP molecules are very difficult to revert to the interface once they are exchanged into bulk phase. Namely,SDS almost entirely occupy the air / water interface. Obviously,the interfacial aggregation behavior of SDS / C12 im SP / Na Cl( 0. 1 mol / L) system can be adjusted by tailor the system composition and thus realize the regulation to the properties of interfacial film.更多还原