手性赖氨酸基Gemini表面活性剂的表面性能  

Surface Activity Properties of Chiral L-Lysine Based Gemini Surfactants

作　　者：梁亚琴[1,2] 胡志勇[1] 曹端林[1] 梁栋[1] 

机构地区：[1]中北大学化工与环境学院,太原030051 [2]长治学院化学系,长治046011

出　　处：《高等学校化学学报》2013年第12期2783-2790,共8页Chemical Journal of Chinese Universities

基　　金：山西省科技攻关项目(批准号:20130313006-3);山西省研究生创新项目(批准号:20133016)资助

摘　　要：用表面张力法、电导法和稳态荧光法研究了手性Gemini表面活性剂[C12-m-C12]Na2(m=2,4,6)和[C12-T-C12]Na2的表面性能及临界胶束聚集数,并计算胶束形成的热力学参数,用圆二色谱法考察了[C12-2-C12]Na2在不同浓度下的立体构型.结果表明,手性Gemini表面活性剂的临界胶束浓度(cmc)和临界表面张力γcmc随着连接基链长增加或刚性增强而增大;ΔG—0m和ΔH—0m为负值,|ΔH—0m|比|-TΔS—0m|小很多,说明胶束化过程为熵驱动的自发放热过程;随着连接基链长增加或刚性增强,ΔG—0m和ΔH—0m逐渐增大,ΔS—0m和临界胶束聚集数逐渐减小,表明其胶束化能力随之降低;当浓度大于cmc时,手性Gemini表面活性剂可形成手性超分子聚集体.Surface activity properties and critical micelle aggregation numbers of [ C12-m-C12 ] N%（ m = 2,4, 6） and [ C12-T-C12 ] Na2 were determined by surface tension, electrical conductivity and steady fluorescene probe methods. The values of critical micelle concentration （ cmc）, 3＇~c and per surfactant molecule （Arin） de- rived from surface tension measurement were found to be in the order of [ C^2-2-C12 ] N%〈 [ C12-4-C12 ] Na2〈 [C12-6-C^2]Na2〈 [C^2-T-C12 ] Na2, which were in aggreement with the sequence of Fro=- The results show that the surface activites of [ C12-m-C12 ] N% and [ C,2-T-C12] Na2 are high. AG~ and AH~ are negative, the absolute value of AHm~ is much smaller than the product of ASm~ and temperature in the aqueous solution. The thermodynamic parameters of micellization of the four Gemini surfactants indicate that the micellization process is an enthopy-driven, exothermic and spontaneous process. As the spacer lengthens from 2 to 6 or the rigidity of the spacer strengthens, which results in a decrease in the ability of micelles to form, AG and AHm of the surfactants increase , ASm~ and critical micelle aggregation numbers of the surfactants decrease . The circular dichroism indicated the formation of chiral helical aggregates above the cmc.

关 键 词：手性 GEMINI表面活性剂 L-赖氨酸 胶束聚集数 胶束形成的热力学参数 

分 类 号：O647.2[理学—物理化学]