偶氮苯三嵌段共聚物的合成、自组装及响应性研究

利用原子转移自由基聚合的方法合成了新型三嵌段共聚物聚(氧化乙烯)甲基醚-b-聚丙烯酸-b-聚6-(4-甲氧基偶氮苯-4′-氧基)己基甲基丙烯酸],通过透射电子显微镜、扫描电子显微镜、激光光散射和紫外-可见光光谱研究了该共聚物在水中的自组装行为及其pH值和光响应性。研究发现该共聚物可自组装形成囊泡。在pH值小于3.4时,胶束粒径随着pH值的减小而急剧增大;pH值大于3.4时,粒径无明显变化。在偏振光的照射下,聚集体会随着照射时间的延长而拉长。

Study on the synthesis,self-assembly and responsive behavior of triblock copolymers containing azobenzene moieties

A new triblock copolymer poly（ethylene oxide）monomethyl ether-b-poly（acrylic aid）-b-poly6-4-methoxy-azobenzene-4′-oxy）hexyl methylacrylate]was synthesized by the atom transfer radical polymerization （ATRP）method.The self-assembly behaviors in aqueous media,pH sensitive and photo-sensitive properties of this copolymer were studied by the means of transmission electron microscopy （TEM）,scanning electron microscopy （SEM）,laser light scattering （LLS）and UV-Vis spectropho-tometer.It is found that the polymer can self-assemble into vesicle structure.With decreasing the pH value,the particle size of the aggregates increases sharply obviously bigger when pH〈3.4.However,there is not significant change for the particle size of micelles when pH〉3.4.Upon irradiation with polarized light,the aggregates are elongated with increasing the irradiation time.