Interfacial dilational properties of tri-substituted alkyl benzene sulfonates at air/water and decane/water interfaces.
The dilational rheological properties of absorbed film of three pairs of structural isomers, tri-substituted alkyl benzene sulfonates, at the air-water and decane-water interfaces have been investigated by drop shape analysis method. The influences of bulk concentration on dilational elasticity and viscosity were expounded. Interfacial tension relaxation method was employed to obtain dilational parameters in a reasonably broad frequency range. The experimental results showed that the meta-alkyl to sulfonate group plays a crucial role in the interfacial dilational properties: the longer meta-alkyl will lead to higher dilational parameters for air-water interface and lower ones for decane-water interface when the total alkyl carbon numbers are equal. For alkyl benzene sulfonates with shorter meta-alkyl, the surface dilational properties are similar to interfacial dilational properties, whereas the surface dilational parameters are obviously higher than the interfacial dilational parameters for alkyl benzene sulfonates with longer meta-alkyl in general. The possible mechanism has been proposed and ensured by Cole-Cole plots.
Zhang
Lei
L
Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, No. 2 North 1 Alley, Zhong guan cun, P.O. Box 2711, 61 section, Beijing 100080, PR China. luyiqiao@hotmail.com
Wang
Xiao-Chun
XC
Gong
Qing-Tao
QT
Zhang
Lu
L
Luo
Lan
L
Zhao
Sui
S
Yu
Jia-Yong
JY