Magnetic Nanoparticles with In Situ Surface Growing Polymeric Brushes as Reactive Pickering Interfacial Catalysts for Biphasic Reactions
作者：Jun Tang, Xiaobo Liu, Shixiong Cao, Shouhao Zhang, Hao Zhang, Lingyu Zhu, Jianbing Ji, Jianli Wang
關鍵字：Pickering, Magnetic Nanoparticles
論文來源：期刊
具體來源：The Journal of Physical Chemistry C
發(fā)表時間：2021年
液相-液相(L - L)兩相體系中催化反應的強化和液滴控制是本研究的重點。磁性材料的表面工程為磁性皮克林界面催化劑(MPICs)的設計提供了一種合理的策略，它在很大程度上彌補了均相催化和多相催化的差距，促進了資源的高效和選擇性轉化。在本研究中，我們通過表面引發(fā)可逆加成-斷裂鏈轉移(SIRAFT)聚合來控制有機堿單體刷的生長，從而獲得磁聚合納米催化劑Fe3O4@PS-PM。表面工程策略使我們能夠簡單地調整表面潤濕性和活性位點含量，以控制乳液催化。在雙相反應體系(酯交換和環(huán)氧化反應)中，乳化體系的催化性能是非乳化體系的兩倍以上，這歸因于Pickering乳液微環(huán)境的增強作用。此外，固有的順磁性表明，MPICs可以迅速從油水界面解吸和回收，并在五次運行中表現出良好的催化活性和穩(wěn)定性。該實用表面工程在磁性可分離PICs的構建和調整方面具有廣闊的前景，并使基于多功能Pickering乳液平臺的綠色化學轉化易于操作。
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
國家自然科學基金項目(21374103、22178317)和浙江省自然科學基金項目(LY18B040004)資助。