Preparation of various Janus composite particles with two components differently combined

Nobutaka Shibata, Daisuke Nagao, Haruyuki Ishii, Mikio Konno

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)


Janus composite particles with a combination of organic and inorganic substances were synthesized by soap-free emulsion polymerization in which an amphoteric initiator of 2,2′-azobis[N-(2-carboxyethyl)-2-2- methylpropionamidine] (VA-057) was employed to introduce a polystyrene (PSt) lobe onto silica cores surface-modified with 3-methacryloxypropyltrimethoxy silane (MPTMS). Thermogravimetric analysis and X-ray photoelectron spectroscopy were used to characterize the surface-modified silica particles and showed that a small amount of MPTMS introduced onto the surface of silica particles could successfully prepare SiO2-PSt Janus particles. The oxide part of SiO2-PSt Janus particles obtained with the polymerization was further surface-modified with 3-aminopropyltriethoxysilane (APS) to introduce positively charged amino groups on the silica surface. The silica surface modified with APS was covered with gold by electroless deposition in which a gold precursor of auric chloride was reduced with ascorbic acid in the presence of polyvinylpyrrolidone. The electroless deposition of gold successfully produced Janus particles with a combination of gold and PSt surfaces. Furthermore, dissolution of the polymer component of the Au-PSt Janus particles in tetrahydrofuran led to another Janus type of particles with an inorganic combination of Au and SiO2.

Original languageEnglish
Pages (from-to)137-142
Number of pages6
JournalColloid and Polymer Science
Issue number1
Publication statusPublished - 2013 Jan


  • Coupling agent
  • Electroless deposition
  • Gold
  • Janus particle
  • Polystyrene
  • Silica

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Polymers and Plastics
  • Colloid and Surface Chemistry
  • Materials Chemistry


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