Thermo-stable hollow magnetic microspheres: preparation, characterization and recyclable catalytic applications
Thermo-stable hollow magnetic microspheres: preparation, characterization and recyclable catalytic applications
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热稳定空心磁性微球：制备、表征和可回收催化应用
DOI：
10.1039/c5ta03553h
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发表时间：
2015-01-01
影响因子：
11.9
通讯作者：
Wu, Daocheng
中科院分区：
文献类型：
--
作者：
Ma, Jingwen;Wu, Youshen;Wu, Daocheng
以均匀的三聚氰胺-甲醛树脂微球为模板，二氧化硅为包覆层，采用层层组装法（LbL）组装，煅烧烧除有机树脂，制备了热稳定的中空磁性微球。胰蛋白酶被其涂覆的聚多巴胺层固定，纳米金颗粒通过LbL方法组装到微球上用于催化应用。用扫描电镜和透射电镜观察了其形貌和中空结构。利用傅里叶变换红外光谱、热重分析和振动样品磁强计研究了其特性。同时，利用紫外-可见光谱对纳米金颗粒和胰蛋白酶的催化性能进行了评价。所制备的中空热稳定磁性微球分散窄，变异系数较低，其粒径在0.5 ~ 5.0 μ m之间，饱和磁化强度在4-30 emu g（-1）之间，可通过不同条件进行调节。结合磁性分离和煅烧活化或再生，这些微球也可以重复使用超过20次的纳米金催化剂和超过32次的胰蛋白酶催化剂再结合，而没有任何显着的催化活性损失，表明其相当大的潜力，可回收的催化应用。
Thermo-stable hollow magnetic microspheres are prepared by layer-by-layer (LbL) assembly on a uniform melamine-formaldehyde resin microsphere template coated by silica and calcination for burning off organic resin. Trypsin is immobilized by their coated polydopamine layer, and nanogold particles are assembled onto the microspheres by the LbL method for catalytic applications. The morphologies and hollow structures are observed by using a scanning electron microscope and transmission electron microscope. The characteristics are investigated by Fourier transfer infrared spectroscopy, thermo-gravimetric analysis and vibrating sample magnetometry. Meanwhile, the catalytic characteristics of nanogold particles and trypsin are evaluated by ultraviolet-visible spectra. The prepared hollow thermostable magnetic microspheres are narrow-dispersed with a relatively low coefficient of variation, and their size ranging from 0.5 mu m to 5.0 mu m and saturation magnetization (4-30 emu g(-1)) can be regulated by different conditions. Combined with magnetic separation and calcination activation or regeneration, these microspheres can also be reused over 20 times for nanogold catalyst and over 32 times for trypsin catalyst reconjugation without any significant loss in catalytic activity, indicating their considerable potential for recyclable catalytic applications.