荧光探针技术研究共溶剂对PEO-PPO-PEO嵌段共聚物溶液胶束的形成及内部结构的影响

THE COSOLVENT EFFECT ON THE MICELLE FORMATION AND MICROSTRUCTURE IN PEO PPO PEO BLOCK COPOLYMER AQUEOUS SOLUTIONS

选择了甲醇、乙醇、正丙醇、乙二醇、乙二胺、乙醇胺及２甲氧基乙醇等七种包括单官能团和双官能团共溶剂、与水组成混合溶剂，并利用荧光探针技术研究了共溶剂对环氧乙烷环氧丙烷环氧乙烷（ＰＥＯＰＰＯＰＥＯ）共聚物水溶液胶束形成及其结构的影响，结果表明，一些共溶剂与水和共聚物ＰＰＯ段都具有较好的混溶性，使形成胶束的ＣＭＴ升高，而其它共溶剂的引入则使得形成胶束的ＣＭＴ降低．从共溶剂对所形成胶束的微结构影响看，能与共聚物链有较强作用的双官能团的共溶剂和有较小分子尺寸的共溶剂有利于使形成的胶束具有较紧密的结构，在此条件下，形成胶束的紧密程度决定了胶束内微极性的大小，而与引入共溶剂的极性大小关系不大．

Cosolvent effect on micelle formation of PEO PPO PEO block copolymer in aqueous solutions were studied by fluorescence probe method in the work. The cosolvents used included methanol(MOH), ethanol(EOH), 1 propanol(POH), 2 methoxyethanol(ME), ethylene glycol(EG), ethanolamine(EA) and ethylenediamine(ED) that were introduced to the aqueous solution of block copolymers as a component of solvent. It was found that the introduction of some cosolvents which were compatible well with both water and PPO segments prevented the micelle formation and made the CMT increase, while other cosolvents were favorable for micelle formation and CMTdecreased. The cosolvents with difunctional group and smaller size were benefited for the formation of micelle with closed packaging nuclei. It was also found, in condition that there was a little cosolvent introduced, the polarity of internal nuclei of micelle was mainly determined by the degree of packaging, but little relevant with the polarity of cosolvents.