Acta Chimica Sinica ›› 2007, Vol. 65 ›› Issue (10): 906-912. Previous Articles     Next Articles

Original Articles

微量量热法研究阴离子表面活性剂在DMA/长链醇体系中CMC和热力学函数

张洪林1, 孔哲1, 闫咏梅1, 李干佐*,2, 于丽2, 李真2   

  1. (1曲阜师范大学化学科学学院 曲阜 273165)
    (2山东大学胶体与界面化学教育部重点实验室 济南 250100)
  • 投稿日期:2006-08-09 修回日期:2006-11-24 发布日期:2007-05-28
  • 通讯作者: 李干佐

Studies on the CMC and the Thermodynamic Function of the Anionic Surfactants in the DMA/Long-chain Alcohol Systems Using a Microcalorimetric Method

ZHANG Hong-Lin1; KONG Zhe1; YAN Yong-Mei1; LI Gan-Zuo*,2; YU Li2; LI Zhen2   

  1. (1 College of Chemical Science, Qufu Normal University, Qufu 273165)
    (2 Key Laboratory for Colloid and Interface Chemistry of Ministry of Education, Shandong University, Jinan 250100)
  • Received:2006-08-09 Revised:2006-11-24 Published:2007-05-28
  • Contact: LI Gan-Zuo

The critical micelle concentration (CMC) and thermodynamic function of anionic surfactant sodium laurate (SLA) and sodium dodecyl sulfate (SDS) in the N,N-dimethylacetamide (DMA)/long-chain alcohol systems were studied using titration microcalorimetric method. The power-time curves of SLA and SDS with the presence of long-chain alcohol (n-heptanol, n-octanol, n-nonanol and n-decanol) in DMA system were determined. Then, from the curves, the CMC and thermodynamic functions (ΔHm0, ΔGm0 and ΔSm0) were obtained by thermodynamic theory. The relationships between temperature, alcohol’s carbon number, concentration and thermodynamic properties were discussed. For SLA or SDS in DMA solution, under the same concentration of alcohol, the values of CMC, ΔHm0 and ΔSm0 increase, while the values of ΔGm0 decrease with the increment of the temperature. Under the same condition of identical temperature and alcohol’s concentration, the values of CMC, ΔHm0Gm0 and ΔSm0 decrease with the increment of the alcohol’s carbon number. In the presence of the same kind of alcohol, the values of CMC and ΔGm0 increase, but the values of ΔHm0 and ΔSm0 decrease with the concentration increasing in alcohol series at the same temperature.

Key words: microcalorimetric method, N,N-dimethylacetamide, sodium laurate, sodium dodecyl sulfate, long-chain alcohol, CMC, thermodynamic function