C_(12)-2-E_n-C(12)·2Br与SDS混合水溶液的胶团化研究

Study of Micellization of C_(12)-2-E_n-C_(12)·2Br and SDS Mixed Aqueous Solutions

与[C_(12)H_(25)N^+(CH_3)_2CH_2]_2·2Br^-(简记为 C_(12)-2-C_(12)·2Br)/C_(12)H_(25)SO_4Na(SDS)混合水溶液相比，随着联接链上乙氧基团(E)数目增加，[C_(12)H_(25)N^+(CH_3)_2]_2C_2H_4(OC_2H_4)_n·2Br^-(简记为 C_(12)-2-E_n-C_(12)·2Br，n=2，3)与 SDS 混合水溶液澄清区域明显增大，C_(12)-2-E_3-C_(12)·2Br/SDS 混合胶团化过程中二组分产生了协同效应，理论预测在澄清区域所能达到的最小临界胶团总浓度(cmc_(T.mim))=0.0339mmol·L^(-1)，对应的 SDS 在溶液体相中的摩尔分数(x_2^(*))=0.447．当水溶液体相中 SDS 摩尔分数(x_2)=0.5时，混合胶团总聚集数(N_T)=36，混合胶团中 SDS 的摩尔分数(x_2~M)=0.43。

With increasing the number of oxyethylene groups in the spacer of [C_(12)H_(25)N^+(CH_3)_2]_2C_2H_4(OC_2H_4)n·2Br^-(C_(12)-2-E_n-C_(12)·2Br,n=2,3),the homogeneous regions in the phase diagrams of aqueous mixture ofC_(12)-2-E_n-C_(12)·2Br with C_(12)H_(25)SO_4Na(SDS)expand obviously in comparison with that of[C_(12)H_(25)N^+(CH_3)_2CH_2]_2·2Br^-/SDS mixed system.There exists a synergism between C_(12)-2-E_n-C_(12)·2Br and SDS during the mixed micel-lization.The minimum critical micelle concentration(cmc_(T,min))in the homogeneous region is 0.0339 mmol.L^(-1)and the corresponding molar fraction(x_2~*)of SDS in the bulk solution is 0.447 estimated by Rosen theory.Atx_2=0.5,the corresponding molar fraction(x_2~M)in the mixed micelle and the total aggregation number(N_T)are0.43 and 36 respectively.