化学学报 ›› 2004, Vol. 62 ›› Issue (23): 2292-2296. 上一篇    下一篇

研究论文

十二烷基聚氧乙烯(n)醚与牛血清白蛋白的团簇化热力学模型

宗李燕, 方云, 夏咏梅, 刘雪锋, 陶可鑫   

  1. 江南大学化学与材料工程学院, 无锡, 214036
  • 投稿日期:2004-03-03 修回日期:2004-06-28 发布日期:2014-02-17
  • 通讯作者: 方云,E-mail:Fangyun57@sina.com E-mail:Fangyun57@sina.com
  • 基金资助:
    国家自然科学基金(No.20371021)资助项目.

Thermodynamic Model of Clusterization between Polyethyleneglycol Mono-Dodecyl Ether and BSA

ZONG Li-Yan, FANG Yun, XIA Yong-Mei, LIU Xue-Feng, TAO Ke-Xin   

  1. School of Chemical & Material Engineering, Southern Yangtze University, Wuxi 214036
  • Received:2004-03-03 Revised:2004-06-28 Published:2014-02-17

用表面张力和稳态荧光猝灭技术研究非离子表面活性剂十二烷基聚氧乙烯(n)醚(AEOn)与牛血清白蛋白(BSA)的团簇化体系,根据质量作用定律建立AEOn与BSA的团簇化热力学模型.从ΔH°>0,ΔS°>0及ΔG°<0可以推知,AEOn束缚胶束与BSA形成软物质团簇是熵驱动的超分子自组装过程,其间的超分子作用力以疏水作用为主.团簇化过程的(ΔG°)clu与表面活性剂自由胶束化过程的(ΔG°)mic皆小于零,且c1<cmc,可以圆满解释在团簇化体系中表面活性剂形成束缚胶束并与大分子经超分子自组装形成软团簇在先,而表面活性剂分子自组装形成自由胶束在后的实验事实.

关键词: 非离子表面活性剂, 十二烷基聚氧乙烯(n)醚, 牛血清白蛋白, 软物质团簇, 热力学模型

The soft cluster composed of polyethyleneglycol mono-dodecyl ether (AEOn) and bovine serum albumin (BSA) was explored by surface tension and steady-state fluorescence quenching technique.There occur two obvious break points in the γ-lgc curves of the above cluster.[Γ], the specific saturation capacity of clusterization in respect of AEOn on BSA, keeps constant when the concentration of BSA increases.[NP]1, the critical aggregation number of bound micelle, is 54 for AEO6 and 52 for AEO7, which means that BSA associates with bound micelles of AEOn rather than monomeric AEOn between the two critical concentrations c1c2.The thermodynamic model of clusterization between AEOn and BSA was deduced from the mass action law.The standard Gibbs free energy of clusterization is negative, which indicates that clusterization is spontaneous and needs no outside driving force as well.ΔH°>0, ΔS°>0 and ΔG°<0, make known that clusterization is entropy driving process, and the supramolecular force is primarily hydrophobic interaction.(ΔG°)clu and (ΔG°)mic are both less than zero and c<1cmc, so the soft cluster of AEOn and BSA forms first by supramolecular interaction when concentration of AEOn approaches c1.For clusterization having finished at c2', micellization begins at c2 accompanied by monomeric AEOn reaching cmc.The above thermodynamic model of clusterization can provide reasonable explanation to the experiments that supramolecular clusterization appears at first whereas self-assembly micellization follows.

Key words: nonionic surfactant, polyethyleneglycol mono-dodecyl ether(AEOn), bovine serum albumin(BSA), soft cluster, thermodynamic model