writer：Jun Tang, Xiaobo Liu, Shixiong Cao, Shouhao Zhang, Hao Zhang, Lingyu Zhu, Jianbing Ji, Jianli Wang
keywords：Pickering, Magnetic Nanoparticles
source：期刊
specific source：The Journal of Physical Chemistry C
Issue time：2021年

  液相-液相(L - L)两相体系中催化反应的强化和液滴控制是本研究的重点。磁性材料的表面工程为磁性皮克林界面催化剂(MPICs)的设计提供了一种合理的策略，它在很大程度上弥补了均相催化和多相催化的差距，促进了资源的高效和选择性转化。在本研究中，我们通过表面引发可逆加成-断裂链转移(SIRAFT)聚合来控制有机碱单体刷的生长，从而获得磁聚合纳米催化剂Fe3O4@PS-PM。表面工程策略使我们能够简单地调整表面润湿性和活性位点含量，以控制乳液催化。在双相反应体系(酯交换和环氧化反应)中，乳化体系的催化性能是非乳化体系的两倍以上，这归因于Pickering乳液微环境的增强作用。此外，固有的顺磁性表明，MPICs可以迅速从油水界面解吸和回收，并在五次运行中表现出良好的催化活性和稳定性。该实用表面工程在磁性可分离PICs的构建和调整方面具有广阔的前景，并使基于多功能Pickering乳液平台的绿色化学转化易于操作。

The intensification of catalytic reaction and droplet manipulation in a liquid-liquid (L-L) biphasic system has been widely focused in this research. The surface engineering of magnetic materials offers a reasonable tactic for the design of magnetic Pickering interfacial catalysts (MPICs), which substantially bridges the gap of homogeneous and heterogeneous catalysis for promoting efficient and selective transformation of resources. In this study, we control the growth of organic base monomer brushes by surface-initiated reversible addition-fragmentation chain transfer (SIRAFT) polymerization to afford a magneto-polymeric nanocatalysts Fe3O4@PS-PM. The surface engineering strategy enables us to simply tune the surface wettability and active site content for the manipulation of emulsion catalysis. In a biphasic reaction system (i.e., transesterification and epoxidation), the catalytic performance of an emulsion system is more than twice that of an unemulsified system, which is attributed to the enhancement effect of the Pickering emulsion microenvironment. In addition, the inherent paramagnetism demonstrates that MPICs can be swiftly desorbed and recovered from the oil?water interface and showed attractive catalytic activity and stability over five runs. The practical surface engineering has promising prospects for construction and adjustment of magnetically separable PICs and enables accessible manipulation of green chemical transformation based on a versatile Pickering emulsion platform.

DOI:10.1021/acs.jpcc.1c06863

国家自然科学基金项目(21374103、22178317)和浙江省自然科学基金项目(LY18B040004)资助。