Preparation of micrometer-sized, monodisperse "janus" composite polymer particles having temperature-sensitive polymer brushes at half of the surface by seeded atom transfer radical polymerization.
Preparation of micrometer-sized, monodisperse "janus" composite polymer particles having temperature-sensitive polymer brushes at half of the surface by seeded atom transfer radical polymerization.
复制标题
DOI：
10.1021/la702994u
复制
发表时间：
2008-01
期刊：
影响因子：
--
通讯作者：
H. Ahmad;Naohiko Saito;Y. Kagawa;M. Okubo
中科院分区：
文献类型：
--
作者：
H. Ahmad;Naohiko Saito;Y. Kagawa;M. Okubo
以膜法制备的聚苯乙烯（PS）和聚甲基丙烯酸甲酯-（氯甲基）苯乙烯（P（MMA-CMS））分散于水溶液中的甲苯液滴为原料，通过溶剂蒸发法制备了具有半球形结构的微米级单分散PS/P（MMA-CMS）复合粒子。通过光学显微镜和电子显微镜两者证实了通过PS和P（MMA-CMS）之间的相分离形成半球形（“Janus”）形态。随后在水分散体系中，以半球形PS/P（MMA-CMS）复合粒子为引发剂，进行了甲基丙烯酸二甲氨基乙酯（DM）的原子转移自由基聚合（ATRP）。聚合后，通过扫描电子显微镜观察，颗粒的形貌由球形变为“蘑菇”形，表明DM在颗粒的一半[P（MMA-CMS）相]内部或表面聚合。1H NMR谱与在DM聚合中作为ATRP引发剂操作的P（MMA-CMS）中的氯甲基官能团一致。
Micrometer-sized, monodisperse polystyrene (PS)/poly[methyl methacrylate-(chloromethyl)styrene] [P(MMA-CMS)] composite particles having hemispherical structure were prepared by solvent evaporation from toluene droplets containing dissolved PS and P(MMA-CMS) dispersed in aqueous solution, which had been prepared using the membrane method. The formation of hemispherical ("Janus") morphology by phase separation between the PS and the P(MMA-CMS) was confirmed by both optical and electron microscopy. Atom transfer radical polymerization (ATRP) of 2-(dimethylamino)ethyl methacrylate (DM) was subsequently carried out in the presence of hemispherical PS/P(MMA-CMS) composite particles in an aqueous dispersed system. After polymerization, the morphology of the particles changed from spherical to "mushroom" shape as observed by scanning electron microscopy, indicating that DM polymerized inside or on the surface of half [P(MMA-CMS) phase] of the particles. 1H NMR spectra were consistent with chloromethyl functional groups in P(MMA-CMS) operating as ATRP initiators in the DM polymerization.