Synthesis of Iron Oxide Rods Coated with Polymer Brushes and Control of Their Assembly in Thin Films
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- 作者：Yun Huang ; Ryohei Ishige ; Yoshinobu Tsujii ; Kohji Ohno
- 刊名：Langmuir
- 出版年：2015
- 出版时间：January 27, 2015
- 年：2015
- 卷：31
- 期：3
- 页码：1172-1179
- 全文大小：635K
- ISSN：1520-5827
文摘
We investigated the surface-initiated atom transfer radical polymerization (SI-ATRP) of methyl methacrylate (MMA) using monodisperse rod-type particles of iron oxide, 尾-FeOOH. The slow hydrolysis of iron(III) chloride yielded monodisperse 尾-FeOOH rods with an average length-to-width ratio, L/W, of 6 (L = 210 nm and W = 35 nm on average). The surfaces of the 尾-FeOOH rods were modified with a triethoxysilane derivative as an ATRP-initiating site, namely, (2-bromo-2-methyl)propionyloxypropyl triethoxysilane. The SI-ATRP of MMA, mediated by a copper complex, was performed using the initiator-coated 尾-FeOOH rods in the presence of a 鈥渟acrificial鈥?free initiator. Well-defined poly(methyl methacrylate) (PMMA) brushes with molecular weights of up to 700鈥?00 could be grafted on the 尾-FeOOH rods with a surface density as high as 0.3 chains/nm2. The resultant polymer-brush-afforded hybrid rods exhibited high dispersibility in various solvents for PMMA without forming aggregates. Thin films were prepared by dip-coating from a suspension of the hybrid rods, and the rods were oriented in a specific direction in the films. The arrangement of the rods could be controlled by varying the chain length of the polymer brush and the withdrawal speed during the dip-coating process.