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  

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

作　　者：宗李燕 方云 夏咏梅 刘雪锋 陶可鑫 

机构地区：[1]江南大学化学与材料工程学院,无锡214036

出　　处：《化学学报》2004年第23期2292-2296,共5页Acta Chimica Sinica

基　　金：国家自然科学基金 (No.2 0 371 0 2 1 )资助项目

摘　　要：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 。The soft cluster composed of polyethyleneglycol mono-dodecyl ether (AEO(n)) and bovine serum albumin (BSA) was explored by surface tension and steady-state fluorescence quenching technique. There occur two obvious break points in the gamma-lg c curves of the above cluster. [Gamma(infinity)], the specific saturation capacity of clusterization in respect of AEO(n) on BSA, keeps constant when the concentration of BSA increases. [N-P](1), the critical aggregation number of bound micelle, is 54 for AEO(6) and 52 for AEO(7), which means that BSA associates with bound micelles of AEO(n) rather than monomeric AEO(n) between the two critical concentrations c(1) similar to c(2). The thermodynamic model of clusterization. between AEO(n) 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. DeltaHdegrees > 0, DeltaSdegrees > 0 and DeltaGdegrees < 0, make known that clusterization is entropy driving process, and the supramolecular force is primarily hydrophobic interaction. (DeltaGdegrees)(clu) and (DeltaGdegrees)(mic) are both less than zero and c(1) < cmc, so the soft cluster of AEO(n) and BSA forms first by supramolecular interaction when concentration of AEO(n) approaches c(1). For clusterization having finished at c(2'), micellization begins at c(2) accompanied by monomeric AEO(n) reaching cure. The above thermodynamic model of clusterization can provide reasonable explanation to the experiments that supramolecular clusterization. appears at first whereas self-assembly micellization follows.

关 键 词：团簇 超分子自组装 胶束 十二烷 聚氧乙烯 烷基 软物质 表面活性剂 热力学模型 大分子 

分 类 号：O631[理学—高分子化学]