Acta Phys. -Chim. Sin. ›› 2015, Vol. 31 ›› Issue (12): 2324-2331.doi: 10.3866/PKU.WHXB201510231

• SOFT MATTER • Previous Articles     Next Articles

Interfacial Adsorption, Dilational Visco-Elasticity and Foam Stability in a Mixed System of Gemini Surfactant/C12En

Bing-Lei. SONG1,Zhao-Lan. ZHAI1,Jian-Xi. ZHAO2,*(),Guo-Jing. SUN2   

  1. 1 The Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, Jiangsu Province, P. R. China
    2 Institute of Colloid and Interface Chemistry, College of Chemistry and Chemical Engineering, Fuzhou University, Fuzhou 350108, P. R. China
  • Received:2015-08-19 Published:2015-12-04
  • Contact: Jian-Xi. ZHAO E-mail:jxzhao.colloid@fzu.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(21473032, 21273040)

Abstract:

The mixed adsorption of a cationic gemini surfactant, ethanediyl-1, 2-bis(dodecyldimethylammonium bromide) 12-2-12), and a nonionic surfactant, polyoxyethylene mono-dodecyl ether (C12En, where n = 4, 10, 23) at the air/water interface was studied using surface tension measurements. The dilational viscoelastic properties of the films that formed at the air/water interface were examined using an interfacial rheology technique that was described using the Lucassen-van den Tempel (LVT) model. The values of the limit elasticity were fitted accordingly. Foams were generated by the mixed surfactant aqueous solutions and the stability of foams determined using the half-life. C12En exhibited attractive interactions towards 12-2-12 within the adsorption films. The average minimum area (Amin) of the adsorbed molecules decreased in the order: 12-2-12/C12E23 > 12-2-12/C12E10 > 12-2-12/C12E4, while the limit elasticity decreased in the reverse order: ε0, fit(12-2-12/C12E4) > ε0, fit(12-2-12/C12E10) > ε0, fit(12-2-12/C12E23) at a comparable concentration of the surfactant in the bulk. Compared with the film adsorbed by 12-2-12 alone, only 12-2-12/C12E4 form had denser structure. Thus, by adding the nonionic component C12E4, which contained a small hydrophilic head group, the interfacial elasticity of the 12-2-12 film increased significantly and the stability of the corresponding foams was effectively enhanced.

Key words: Mixed adsorption, Cationic gemini surfactant, Nonionic conventional surfactant, Interfacial elasticity, Foam stability

MSC2000: 

  • O647