Adsorption kinetics of asymmetric gemini surfactants at air/water interface

作者：Zhou Tian Hua; Zhao Jian Xi^*

来源：Acta Physico - Chimica Sinica, 2007, 23(7): 1047-1052.

• asymmetric Gemini surfactants
• adsorption kinetics
• hydrophobic interaction

Asymmetric Gemini surfactants CmH2m+1OCH2CH(OH)CH2N+(CH3)(2)C8H17Br, referred to as C(m)OhpNC(8) (m= 10, 12 and 14), were synthesized. This type of surfactant molecule has a head region (a hydroxyl and a quaternary ammonium linked by one methylene group) with a small size and two alkyl chains with different lengths. The maximum bubble pressure technique was used to investigate the adsorption kinetics of C(m)OhpNC(8) aqueous solution below their critical micelle concentrations at the air/water interface. The results showed an obvious kinetic process for the adsorption of C(m)OhpNC(8). When C(m)OhpNC(8) were adsorbed on the freshly formed interface, the adsorption process was pure diffusion controlled. When some molecules existed at the interface, the adsorption barrier (E-a) appeared, which reduced with increasing m. This indicated that those molecules with long alkyl chain migrated more easily from the subsurface into the surface, which was attributed to enhanced hydrophobic interaction between the alkyl chains with increasing m.

• 出版日期2007-7
• 单位福州大学