writer：Linbin Feng, Jianli Wang*, Liang Chen, Meizhen Lu, Zhi Zheng, Ren Jing, Hualiang Chen, Xianbo Shen.
keywords：heterogeneous catalysis，microreactors，Montanari oxidation，nanoparticles，Pickering emulsions，phase-transfer catalysis
source：期刊
specific source：ChemCatChem
Issue time：2015年

This work described a general strategy to enhance a typical organic-aqueous heterogeneous green oxidation reaction by introducing surface tunable magnetic nanoparticles into  liquids to form a controllable Pickering emulsion. We synthesized cross-linked polystyrene (PS)-covered Fe₃O₄ nanoparticles grafting with different N-alkyl imidazoles, and systematically discussed the effect of surface properties on the formation of emulsions. By loading of such particles, the dichloromethane-water-based  2,2,6,6-tetramethylpiperidine-1-oxyl-mediated Montanari oxidation system was converted from the unstable millimeter-scale dispersions into a stable micrometer-scale emulsion, which significantly  reduced the reactant transfer distance and resulted in a significantly high overall reaction rate. This reaction efficiency is  in terms of unique properties inherent in an emulsion,including the self-assembled of Fe₃O₄/PS and Fe₃O₄/PS[im-C_n]Cl(n=1,4,6,10) nanoparticles, well ensuring a large specific surface area of the water-oil interface.