P123重水溶液的物理凝胶化及凝胶结构

Physical Gelation and Structures of P123 in D_2O Solution

利用1H NMR方法,研究了高浓度的P123(PEO20PPO70PEO20)在重水溶液中的溶胶-凝胶转变过程.升高温度使得体系发生溶胶-凝胶转变,进一步升高温度,体系发生凝胶-溶胶转变.通过对不同质子基团的谱线宽度和化学位移偏移的分析,同时结合流变学频率扫描和同步辐射(SR)研究,发现质量分数为30%的P123的重水溶液在凝胶化过程中,结构经历了由立方相(cubic)-六角柱状相(hcp)-层状相(lamellar)的转变过程,其中立方相为面心立方(fcc)和六角密堆积球状相(hcps)的混合相.高温时从凝胶到溶胶的转变主要体现为P123形成富集区与水发生相分离的过程.

1H NMR was used to study the sol-gel transition of triblock copolymer P123 （PEO20 PPOToPEO20, 30% ） in D2O solution by analyzing the half-height width and the chemical shift of the proton signals of the P123. The changes of gel structures for P123 （30%） was investigated with theological method and synchrotron radiation （SR）. With the increase of temperature, the transition of gel phases from fcc ＋ heps to hcp structure and finally to lamellar structure were found. Moreover, the phase separation occurred for the P123 in D2O solution at high temperature.