烷基聚氧乙烯醚磺基甜菜碱的构效关系研究

Relationship between structure and physicochemical properties of polyoxyethylene sulfobetaines surfactants

为了研究非-两性离子混合型表面活性剂的构效关系,以乙氧基(EO)长度n分别为1,2,3和4的N,N-二甲基-N-十二烷基聚氧乙烯醚磺基甜菜碱(C_(12)EO_nSBe)为研究对象,利用滴体积法、时间分辨荧光法等获得C_(12)EO_nSBe的临界胶束浓度(cmc)、胶束聚集数(Nm)等性质参数。实验结果表明:与分子结构相近的传统十二烷基磺基甜菜碱(C_(12)SBe)相比,C_(12)EO_nSBe的cmc更低;随着n增大,C_(12)EO_nSBe的cmc降低,饱和吸附量(Γ_m)增大,分子占据面积(A_(min))减小,临界胶束聚集数(N_(m,c))减小。

In order to find the structure-performance relationship of nonionic-zwitterionic hybrid surfactants,N,N-dimethyl-N-dodecyl polyoxyethylene（ n） sulfobetaines（ C（12）EOnSBe） with separate polyoxyethylene length（ n = 1-4） were taken as studying object. Data for critical micelle concentration（ cmc） and number of micellar aggregates（ Nm） were obtained by drop-volume method and time-resolved fluorescence method.Results showed that,as comparing with the conventional N,N-dimethyl-N-dodecyl sulfobetaine（ C（12）SBe）,cmc of C（12）EOnSBe（ n = 1-4） is lower. Following the increase of n,cmc of C（12）EOnSBe（ n = 1-4）declines; saturated adsorption（ Γm） increases; the minimum molecular cross-sectional area（ A（min）） deceases;and the critical micellar aggregation number（ N（m,c）） decreases as well.