Ge Jianping, Huynh Tuan, Hu Yongxing, Yin Yadong
Department of Chemistry, University of California, Riverside 92521, USA.
Nano Lett. 2008 Mar;8(3):931-4. doi: 10.1021/nl080020f. Epub 2008 Feb 1.
We report the synthesis of magnetically responsive hierarchical assemblies of silica colloids that can be used as recoverable supports for nanocatalysts. Each assembly is composed of a central magnetite/silica composite core and many small satellite silica spheres. The two regions are held together as a stable unit by a polymer network of poly(N-isopropylacrylamide). The central magnetite particles are superparamagnetic at room temperature with strong magnetic response to external fields, thus providing a convenient means for separating the entire assembly from the solution. The satellite silica particles provide large surface areas for loading nanocatalysts through the well-developed silane chemistry. As an example, we demonstrate the use of such magnetically responsive hierarchical assemblies as recoverable supports for Au nanocatalysts for the reduction of 4-nitrophenol with NaBH4.
我们报道了二氧化硅胶体的磁响应分级组装体的合成，该组装体可用作纳米催化剂的可回收载体。每个组装体由一个中心磁铁矿/二氧化硅复合核和许多小的卫星二氧化硅球体组成。这两个区域通过聚（N-异丙基丙烯酰胺）聚合物网络作为一个稳定单元结合在一起。中心磁铁矿颗粒在室温下是超顺磁性的，对外部磁场有强烈的磁响应，从而提供了一种将整个组装体从溶液中分离出来的便捷方法。卫星二氧化硅颗粒通过成熟的硅烷化学为负载纳米催化剂提供了大的表面积。作为一个例子，我们展示了这种磁响应分级组装体作为金纳米催化剂的可回收载体用于用硼氢化钠还原4-硝基苯酚的用途。
