聚醚树枝体－聚丙烯酸嵌段共聚物的水溶液自组装行为

应用UV－Vis、荧光、光物理探针、动态激光光散射和透射电镜(TEM)方法研究了聚醚树枝体与聚丙烯酸两亲嵌段共聚物(Dendr,PE-PAA)在水溶液中分子自组装行为。实验结果表明通过聚醚树枝体嵌段的疏水作用，易缔合形成聚集体，具有很低(10^-6～10^-7mol·L^-1)的临界缔合浓度(cac)。透过电镜观察到聚集体具有双层膜结构的球状、单室囊泡。临界缔合浓度(cac)以及聚集体的大小对枝状体的代数(Gi)及线性体的聚合度(n)具有明显的依赖关系。

Self-assembly of dendritic polyether-poly(acrylic acid) block copolymer in aqueous solution

Fluorescence, UV-Vis spectra, photophysical probe, TEM and dynamic light scattering have been used for investigation of the self-assembly of Dendr. PE-PAA copolymer. The experimental results show that these amphiphilic copolymers with a linear poly(acrylic acid) as the hydrophilic block and a spherical polyether dendrimer as hydrophobic block self-assemble easily to form a stock aggregate by hydrophobic driving force in aqueous solution. The critical aggregation concentrations ( cac ) for different structural amphiphilic copolymers determined by pyrene probe are very low ( 10- 7～10-6 mol· L- 1 ). The typical vesicular aggregates with a layer thickness of 3～5 nm were observed by transmission electron microscopy. The cac and size of the aggregates derived from these dendritic amphiphiles in aqueous solution are highly dependent on the generation of dendrimer and the length of linear chains.