Electromagnetic Field Shielding Polyurethane Nanocomposites Reinforced with Core–Shell Fe–Silica Nanoparticles
Electromagnetic Field Shielding Polyurethane Nanocomposites Reinforced with Core–Shell Fe–Silica Nanoparticles
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DOI：
10.1021/jp2052536
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发表时间：
2011-07
影响因子：
3.7
通讯作者：
Jiahua Zhu;Suying Wei;N. Haldolaarachchige;D. Young;Zhanhu Guo
中科院分区：
文献类型：
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作者：
Jiahua Zhu;Suying Wei;N. Haldolaarachchige;D. Young;Zhanhu Guo
介绍了一种改进的Stober方法，以3-氨丙基三乙氧基硅烷（APTES）为引发剂，使金属颗粒表面与二氧化硅相容，合成Fe@SiO2纳米颗粒（NPs）。高分辨率透射电子显微镜（HRTEM）和选区电子衍射（SAED）的结果表明，一个高度结晶的铁芯涂有一层均匀的二氧化硅。通过表面引发聚合（SIP）方法制备了71wt%Fe@FeO和71wt%Fe@SiO2纳米粒子填充的聚氨酯（PU）纳米复合材料。所得纳米复合材料的磁性比纯Fe@FeO纳米颗粒的磁性显著增加，表明纳米颗粒分散在PU基质中后变得磁性更硬。热重分析（TGA）结果表明，由于SiO2壳层的阻隔作用，Fe@SiO2纳米粒子和Fe@SiO2/PU纳米复合材料的热稳定性和抗氧化性能分别优于Fe@FeO和Fe@FeO/PU。同时，硅壳大大提高了硅的耐腐蚀性能。
A modified Stober method is introduced to synthesize Fe@SiO2 nanoparticles (NPs) using 3-aminopropyltriethoxysilane (APTES) as a primer to render the metal particle surface compatible with silica. High-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED) results indicate a highly crystalline iron core coated with a uniform layer of silica. Polyurethane (PU) nanocomposites filled with 71 wt % Fe@FeO and 71 wt % Fe@SiO2 NPs are fabricated via a surface-initiated polymerization (SIP) method. The significantly increased coercivity of the resulting nanocomposites than that of the pure Fe@FeO NPs indicates that the NPs become magnetically harder after being dispersed in the PU matrix. Both Fe@SiO2 NPs and Fe@SiO2/PU nanocomposites exhibit better thermal stability and antioxidation capability than Fe@FeO and Fe@FeO/PU, respectively, owing to the barrier effect of the silica shell, revealed by the thermalgravimetric analysis (TGA). Meanwhile, the silica shell greatly r...