Thermodynamic Properties of Sulfobetaine-Type Surfactants |
| |
Authors: | Hai-lin Zhu Zhi-yong Hu Jian-long Wang Duan-lin Cao |
| |
Affiliation: | 1. School of Chemical Engineering and Environment, North University of China, Taiyuan, 030051, Shanxi, China
|
| |
Abstract: | Sulfobetaine-type surfactants containing a hydroxy group were synthesized by the reaction of long chain monoalkyl dimethyl tertiary amine with 3-chloro-2-hydroxypropanesulfonic acid sodium salt. The structures were characterized by 1H NMR and ESI-MS. Their critical micelle concentrations (CMC) in aqueous solution were determined by the plate method in the temperature rang from 298.15 to 328.15 K. The thermodynamic parameters of micellization ( $Delta G_{text{mic}}^{theta}$ , $Delta H_{text{mic}}^{theta}$ and $Delta S_{text{mic}}^{theta}$ ) and surface adsorption ( $Delta G_{text{ad}}^{theta}$ , $Delta H_{text{ad}}^{theta}$ and $Delta S_{text{ad}}^{theta}$ ) were calculated from CMC data. The results showed that the micellization and surface adsorption of these surfactants in aqueous solution was a spontaneous and entropy-driven process. The micellization and surface adsorption became easier when the alkyl chain length increased from 12 carbon atoms to 14. The enthalpy–entropy compensation of micellization and adsorption was investigated. The compensation temperature were found to be (311 ± 2) K for both micellization and adsorption. The $Delta H_{text{mic}}^{*}$ and $Delta H_{text{ad}}^{*}$ decreased, but the $Delta S_{text{mic}}^{*}$ and $Delta S_{text{ad}}^{*}$ increased with increasing the hydrophobic chain length from 12 to 14. |
| |
Keywords: | Sulfobetaine Hydroxysultaine Zwitterionic Thermodynamics Micellization Adsorption |
本文献已被 SpringerLink 等数据库收录! |