Composite Microdiscs with a Magnetic Belt: Preparation, Chaining Properties, and Use as Switchable Catalyst Carriers

Matti Knaapila, Henrik Høyer, Geir Helgesen

Research output: Contribution to journalJournal articleResearchpeer-review


We describe an emulsion-based preparation of patchy composite particles (diameter of 100-500 mu m) consisting of a disclike epoxy core and a belt of porous polystyrene particles (diameter of 30 mu m) with magnetite within the pores. Compared to the magnetically uniform polystyrene particles, the spontaneous aggregation of composite particles is suppressed when dispersed into liquid, which is attributed to the increased particle size, reduced magnetic susceptibility, and the shape of the magnetic domain distribution within the particles (spherical versus a belt). When the composite particles are coated by platinum-palladium layer we demonstrate they can be employed as switchable catalyst carriers, moving from one liquid phase to another when controlled by an external magnetic field.
Original languageEnglish
JournalA C S Applied Materials and Interfaces
Issue number14
Pages (from-to)7795-7800
Number of pages6
Publication statusPublished - 2015


  • Magnetic particles
  • Patchy particles
  • Hybrid materials
  • Active materials
  • Anisotropy
  • Catalyst

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