Synthesis of Hybrid Silica Nanoparticles Densely Grafted with Thermo and pH Dual-Responsive Brushes via Surface-Initiated ATRP
Synthesis of Hybrid Silica Nanoparticles Densely Grafted with Thermo and pH Dual-Responsive Brushes via Surface-Initiated ATRP
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DOI：
10.1021/acs.macromol.6b01792
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发表时间：
2016-12
期刊：
影响因子：
5.5
通讯作者：
Lei Wu;Ulrich Glebe;A. Böker
中科院分区：
文献类型：
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作者：
Lei Wu;Ulrich Glebe;A. Böker
这项工作介绍了通过表面引发原子转移自由基聚合 (ATRP) 合成明确的热和 pH 双重响应的聚 (N-异丙基丙烯酰胺)-b-聚(4-乙烯基吡啶)-接枝二氧化硅纳米颗粒 (SNPs-g-PNIPAM-b-P4VP)。 ATRP 引发剂附着在二氧化硅纳米颗粒的表面，然后附着 N-异丙基丙烯酰胺 (NIPAM) 的 ATRP。在表面引发的 ATRP 过程中，利用游离牺牲引发剂和卤素交换来以受控方式进行聚合。由于保留了聚合物链的端基官能团，用 4-乙烯基吡啶 (4VP) 从获得的 PNIPAM 接枝 SNP (SNPs-g-PNIPAM) 成功进行了扩链。详细研究了链延伸的动力学，显示了这种重新引发过程的活性。随后用碘甲烷对外部 P4VP 嵌段进行季铵化，使得合成的杂化纳米粒子良好地分散在水溶液中。这种良好的分散性提供了...
This work introduces a synthesis of well-defined thermo and pH dual-responsive poly(N-isopropylacrylamide)-b-poly(4-vinylpyridine)-grafted silica nanoparticles (SNPs-g-PNIPAM-b-P4VP) via surface-initiated atom transfer radical polymerization (ATRP). ATRP initiators were attached onto the surfaces of silica nanoparticles followed by ATRP of N-isopropylacrylamide (NIPAM). During the surface-initiated ATRP, free sacrificial initiator and halogen exchange were utilized to render the polymerization in a controlled manner. Because of the retention of the polymer chain’s end-group functionality, chain extension with 4-vinylpyridine (4VP) from the obtained PNIPAM-grafted SNPs (SNPs-g-PNIPAM) was successfully conducted. Kinetics of the chain extension was studied in detail, showing the livingness of this reinitiation process. Subsequent quaternization of the outer P4VP block with methyl iodide led to the synthesized hybrid nanoparticles being well dispersed in aqueous solution. This well dispersibility affords the...