Tunable Assembly of Block Copolymer Tethered Particle Brushes by Surface-Initiated Atom Transfer Radical Polymerization
Tunable Assembly of Block Copolymer Tethered Particle Brushes by Surface-Initiated Atom Transfer Radical Polymerization
复制标题
通过表面引发原子转移自由基聚合嵌段共聚物系留粒子刷的可调组装
DOI：
10.1021/acsmacrolett.0c00158
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发表时间：
2020
影响因子：
7.015
通讯作者：
Pietrasik, Joanna
中科院分区：
文献类型：
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作者：
Wang, Zongyu;Lee, Jaejun;Wang, Zhenhua;Zhao, Yuqi;Yan, Jiajun;Lin, Yu;Li, Sipei;Liu, Tong;Olszewski, Mateusz;Pietrasik, Joanna
提出了以二氧化硅粒子为原料，通过表面引发原子转移自由基聚合(SI-ATRP)合成SiO_2-g-PMMA/PMMA-b-PS单双峰嵌段共聚粒子刷子的方法。首先，通过控制聚合度和接枝密度，用普通ATRP制备PMMA嵌段。在第二步中，使用低百万分之一的铜催化剂通过扩链合成了PS嵌段。SiO_2-g-PMMA-BR大分子引发剂浓度的变化对扩链产物的形态有显著影响。在小浓度范围内，部分终止形成了双峰刷子结构，而随着大分子引发剂浓度的增加，刷子结构更加均匀。具有双峰结构的刷子纳米粒子组装成线状聚集体，与稀疏(均聚物)刷子粒子组成的系统中的结构相似。形态对结构形成的意想不到的影响表明了刷状颗粒材料中微观结构的控制机会。
A strategy to synthesize SiO2-g-PMMA/PMMA-b-PS mono- and bimodal block copolymer particle brushes by surface-initiated atom transfer radical polymerization (SI-ATRP) from silica particles is presented. First, PMMA blocks were prepared by normal ATRP with controlled degree of polymerizations and grafting density. In a second step, the PS block was synthesized through a chain extension using low parts per million of Cu catalyst. Variation of the SiO2-g-PMMA-Br macroinitiator concentration had a pronounced effect on the modality of the chain extension product. In the limit of small concentration, partial termination resulted in bimodal brush architectures, while more uniform brush architectures were observed with increasing concentration of macroinitiator. Brush nanoparticles with bimodal architectures assembled into string-like aggregates that bore a resemblance to structures found in systems comprised of sparse (homopolymer) brush particles. The unexpected effect of modality on structure formation points to opportunities in controlling microstructures in brush particle materials.