由可控聚合反应直接制备不同形貌的聚集体

由可控聚合,包括活性阴离子和自由基聚合直接制备不同形貌纳米材料,是近几年来合成化学领域的一个重要研究成果.与两亲性嵌段共聚物在选择性溶剂中自组装方法不同,在选择性溶剂中进行的分散聚合,首先生成两亲性嵌段共聚物,并逐渐增加第二段聚合物的链长,以实现相分离,形成球形胶束;聚合物链继续增长,实现形貌转变,从而制备预期的聚合物形貌,包括球形胶束、纳米棒、纳米线、囊泡和复合囊泡等.本文综述了乳液聚合法制备球形胶束等形貌;描述了不同聚合体系形成的形貌以及它们的性质和应用,讨论了形貌的形成机理和控制方法,同时指出了存在的问题.

Direct preparation of various morphologies of polymeric aggregates by controlled polymerization

This article reviews the preparation of various morphologies of the polymeric aggregates in the dispersion or emulsion polymerization with macro-initiator （or transfer agent） as stabilizer. The polymerization-induced self-assembling and reorganization are responsible for the formation of various morphologies. Generally, the controlled/living polymerizations including living anionic polymerizations and controlled radical polymerizations are applied in the preparations. During the polymerization, the block copolymers are formed. With gradual increase of the second block in the copolymers, the phase is seperated, then forms spherical micelles with the second blocks as core and macro initiator as shell. Further increase of the polymer chains will result in the transform of the morphologiesfrom the spherical micelles to other morphologies. The various morphologies formed in several polymerization systems are described, the possible mechanism of morphologies formation are proposed and the questions and further developments orientation in this areas are presented in this paper.