Acta Phys. -Chim. Sin. ›› 2010, Vol. 26 ›› Issue (03): 631-637.doi: 10.3866/PKU.WHXB20100319

• COLLOID AND INTERFACE CHEMISTRY • Previous Articles     Next Articles

Interfacial Dilational Properties of Tri-Substituted Alkyl Benzene Sulfonates

LI Xiu-Lan, ZHANG Lei, GONG Qing-Tao, ZHANG Lu, ZHAO Sui, YU Jia-Yong   

  1. Geological and Scientific Research Institute of Shengli Oilfield Co. Ltd., SINOPEC, Dongying 257015, Shandong Province, P. R. China; Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
  • Received:2009-10-11 Revised:2009-12-21 Published:2010-03-03
  • Contact: ZHANG Lu E-mail:luzhang523@hotmail.com; luyiqiao@hotmail.com

Abstract:

The dilational rheological properties of five types of surfactants: sodium 3,4-dihexylbenzene sulfonate (66), sodium 3,4-diheptylbenzene sulfonate (77), sodium 2-ethyl-4,5-dihexylbenzene sulfonate (266), sodium 2-propyl-4,5-dihexylbenzene sulfonate (366), and sodium 2-butyl-4,5-dihexylbenzene sulfonate (466) at the air-water and decane-water interfaces were investigated by a drop shape analysis method. The influence of hydrophobic chains located at different positions on the benzene ring on the interfacial molecular behavior was investigated. Experimental results showed that the hydrophobic chains that were located at different positions affected the dilational elasticity and dilational viscosity differently. The dilational elasticity appeared to increase with an increase in the length of the hydrophobic group and the dilational viscosity behaved differently. The short alkyl chain (2-4) ortho to the sulfonate group had little influence on the dilational viscosity, while an increase in the long meta alkyl group played an important role in the surface relaxation process, which resulted in higher surface dilational viscosity. The insertion of decane molecules from the oil phase weakened the strong interactions between the meta-alkyl chains and therefore the interfacial dilational parameters were obviously lower than those of the surface. We also found that the interfacial dilational viscosities of a pair of structural isomers, 77 and 266, were approximately equal.

Key words: Sodiumalkyl benzene sulfonate, Surface, Interface, Dilational elasticity, Dilational viscosity

MSC2000: 

  • O647