聚氧乙烯/聚氧丙烯/聚氧乙烯两亲嵌段共聚物胶束的生成特性

MICELLIZATION OF AMPHIPHILIC POLY(ETHYLENE OXIDE)- POLY(PROPYLENE OXIDE)-POLY(ETHYLENE OXIDE) BLOCK COPOLYMER

应用无外加探针循环伏安法研究了聚氧乙烯 /聚氧丙烯 /聚氧乙烯两亲嵌段共聚物 ( PluronicF1 2 7,简为 F1 2 7)在铂电极上的循环伏安行为 ,探讨了 F1 2 7在铂电极上的电化学反应机理 .根据 F1 2 7在水溶液中不同形态聚集体扩散系数的测定 ,得知球形胶束生成的第一临界胶束浓度 c1,c,m为 3 .72× 1 0 -4m ol· L-1,球形胶束向棒状胶束转变的第二临界胶束浓度 c2 ,c,m为 1 .49× 1 0 -3 mol· L-1,并由探针芘在F1 2 7溶液中的稳态荧光各向异性的测定得到证实 .

The cyclic voltammetric behavior on platinum electrode of an amphiphilic block copolymer PEO PPO PEO (poly(ethylene oxide) block poly(propylene oxide) block poly(ethylene oxide)) in aqueous solutions is investigated without probe. The mechanism of the electrochemical reaction of F127 on platinum electrode is deduced. The diffusion coefficients of different shape aggregates formed by F127 are determined on this basis. The first critical micelle concentration ( c 1,c,m ) and the second one ( c 2,c,m ), corresponding to the spherical to rod like transition, are 3.72×10 -4 mol·L -1 and 1.49×10 -3 mol·L -1 respectively, which could be confirmed by the fluorescent anisotropy of pyrene in the F127 aggregates.