Enhancing Initiation Efficiency in Metal-Free Surface-Initiated Atom Transfer Radical Polymerization (SI-ATRP)
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- 作者：Jiajun Yan ; Xiangcheng Pan ; Michael Schmitt ; Zongyu Wang ; Michael R. Bockstaller ; Krzysztof Matyjaszewski
- 刊名：ACS Macro Letters
- 出版年：2016
- 出版时间：June 21, 2016
- 年：2016
- 卷：5
- 期：6
- 页码：661-665
- 全文大小：342K
- 年卷期：0
- ISSN：2161-1653
文摘
Well-defined polymer-inorganic hybrid materials were prepared via metal-free surface-initiated atom transfer radical polymerization (SI-ATRP) with 10-phenylphenothiazine (PhPTZ) as the photocatalyst and 2-bromo-2-phenylacetate initiator tethered to silica surfaces. Initiation efficiency and, hence, graft density were significantly enhanced by this very reactive initiator. The polymerization kinetics, effect of initiator structures, particle sizes, and catalyst concentrations were investigated. Well-defined hybrid particles were prepared at a low catalyst concentration (0.02 mol % or 0.1 mol % to monomer). Poly(methyl methacrylate) (PMMA) with number-average molecular weight of 3.65 × 104, dispersity of 1.43, and graft density of 0.60 chain/nm2 was grafted from the surface of silica nanoparticles. The hybrid materials were characterized with size exclusion chromatography (SEC), thermogravimetric analysis (TGA), dynamic light scattering (DLS), and transmission electron microscopy (TEM).