Acta Chimica Sinica ›› 2020, Vol. 78 ›› Issue (9): 954-960.DOI: 10.6023/A20060208 Previous Articles     Next Articles


多功能Fe3O4@SiO2 Janus颗粒

赵若彤a, 韩天昊c, 孙大吟b, 山丹d, 刘正平a, 梁福鑫b   

  1. a 北京师范大学 化学学院 北京 100875;
    b 清华大学 化学工程系 高分子科学与工程研究所 北京 100084;
    c 中国石油化工股份有限公司石油化工科学研究院 北京 100083;
    d 首都医科大学附属北京妇产医院 北京 100020
  • 投稿日期:2020-06-04 发布日期:2020-07-15
  • 通讯作者: 刘正平, 梁福鑫;
  • 基金资助:

Multifunctional Fe3O4@SiO2Janus Particles

Zhao Ruotonga, Han Tianhaoc, Sun Dayinb, Shan Dand, Liu Zhengpinga, Liang Fuxinb   

  1. a College of Chemistry, Beijing Normal University, Beijing 100875;
    b Institute of Polymer Science and Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084;
    c Sinopec Research Institute of Petroleum Processing, China Petroleum and Chemical Corporation, Beijing 100083;
    d Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing 100020
  • Received:2020-06-04 Published:2020-07-15
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Nos. 51673119, 51622308).

Fe3O4@SiO2 particles were synthesized by a solvothermal method and a classical stÖber method. Superparamagnetic Fe3O4 was the core, and a sol-gel coating of SiO2 was the shell. After the SiO2 surface was modified with amino groups, benzaldehyde was conjugated to the particles by a Schiff base reaction. The Fe3O4@SiO2 particles were emulsified in paraffin/water as a solid emulsifier to obtain an oil-in-water Pickering emulsion. After cooling the paraffin, the particles were fixed on the surface of the emulsion droplets. The particles were etched in ammonium fluoride aqueous solution, and Janus particles with different structures could be obtained by adjusting the etching time. Via the in situ growth of metal Pt or Ag nanoparticles, superparamagnetic Fe3O4@SiO2-Pt or Fe3O4@SiO2-Ag Janus particles were obtained. The movement of Fe3O4@SiO2-Pt Janus particles was observed due to the catalytic decomposition of hydrogen peroxide aqueous solution. It was found that in the short term, there was a linear motion, while in the long term, the motion direction and trajectory were random. Fe3O4@SiO2-Ag Janus particles were used as magnetic solid surfactants to stabilize the emulsions and catalyze the nitro reduction. About 60% of the surficial area of the Janus particles was modified by phenyl groups, while the remaining 40% was covered with Ag nanoparticles. Under the premise of maintaining the Janus balance, the whole particle became more hydrophobic, which was conducive to the formation of the water-in-oil emulsion. In addition, the Ag side of the Janus particles was towards the aqueous phase, and the opposite hydrophobic side was towards the oil phase. The Janus particles possessed a fixed orientation assembly at the oil-water interface. The assemble membrane possessed Janus characteristics, and it facilitated the stable dispersion of the emulsion and the catalysis. The method has the advantages of a simple principle, capability for mass production, universality and versatility. It is expected that Janus particles will be used to more precisely regulate the zoning with different functional substances.

Key words: Janus particle, magnetic response, self-driven, solid emulsifier, catalysis