Zhang Yuxuan, Yu Liangliang, Dai Xiaocong, Zhang Li, Tan Jianbo
Department of Polymeric Materials and Engineering, School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006, China.
Guangdong Provincial Key Laboratory of Functional Soft Condensed Matter, Guangzhou 510006, China.
ACS Macro Lett. 2019 Sep 17;8(9):1102-1109. doi: 10.1021/acsmacrolett.9b00509. Epub 2019 Aug 16.
Polymerization-induced self-assembly (PISA) has served as a versatile platform for the large-scale preparation of well-defined block copolymer nano-objects. It appears to be "common sense" that block copolymers with narrow molecular weight distributions are inevitable. In this study, we have conducted the direct comparison of reversible addition-fragmentation transfer (RAFT)-mediated PISA of 2-hydroxypropyl methacrylate (HPMA) using polymethacrylate- and polyacrylate-based macro-RAFT agents. Taking advantage of the poor RAFT controllability of polyacrylate-based macro-RAFT agents with respect to HPMA, uniform submicron-sized polymeric microspheres were prepared by photoinitiated RAFT-mediated PISA of HPMA. The diameter of polymeric microspheres can be precisely controlled by further chain-extension of PHPMA. Finally, uniform epoxy-functionalized multicompartment block copolymer particles (MBCPs) were prepared by a two-step photoinitiated RAFT-mediated PISA with poly(glycidyl methacrylate) (PGlyMA) as the third block. The performance of MBCPs as Pickering emulsifiers was evaluated in detail. This study not only expands the scope of RAFT-mediated PISA for preparing well-defined polymer particles but also provides important insights into the mechanism of RAFT-mediated PISA.
聚合诱导自组装（PISA）已成为大规模制备结构明确的嵌段共聚物纳米物体的通用平台。分子量分布窄的嵌段共聚物是不可避免的，这似乎是“常识”。在本研究中，我们使用基于聚甲基丙烯酸酯和聚丙烯酸酯的大分子RAFT试剂，对甲基丙烯酸2-羟丙酯（HPMA）的可逆加成-断裂链转移（RAFT）介导的PISA进行了直接比较。利用基于聚丙烯酸酯的大分子RAFT试剂对HPMA的RAFT可控性较差这一特点，通过光引发RAFT介导的HPMA的PISA制备了均匀的亚微米级聚合物微球。聚合物微球的直径可以通过PHPMA的进一步扩链精确控制。最后，以聚甲基丙烯酸缩水甘油酯（PGlyMA）为第三嵌段，通过两步光引发RAFT介导的PISA制备了均匀的环氧官能化多隔室嵌段共聚物颗粒（MBCP）。详细评估了MBCP作为Pickering乳化剂的性能。本研究不仅扩展了RAFT介导的PISA制备结构明确的聚合物颗粒的范围，还为RAFT介导的PISA的机理提供了重要见解。
