Shape-controlled syntheses of magnetite microparticles and their magnetorheology

Hiroya Abe, Takashi Naka, Kazuyoshi Sato, Yoshikazu Suzuki, Masami Nakano

研究成果: Article査読

7 被引用数 (Scopus)


Magnetic microspheres in a concentrated suspension can be self-assembled to form chain structures under a magnetic field, resulting in an enhanced viscosity and elasticity of the suspension (i.e., the magnetorheological (MR) effect). Recently, interest has been raised about the relationship between nonspherical particles, such as octahedral particles and the MR effect. However, experimental studies have not made much progress toward clarifying this issue due to the difficulty associated with synthesizing microparticles with well-defined shapes and sizes. Here, we presented a method for the shape-controlled synthesis of magnetite (Fe3O4) microparticles and investigated the MR effects of two suspensions prepared from the two shape-controlled samples of Fe3O4 microparticles. Our method, which was based on the polyol method, enabled the preparation of spherical and octahedral Fe3O4 microparticles with similar sizes and magnetic properties, through a reduction of α-FeOOH in a mixed solvent of ethylene glycol (a polyol) and water. The water played an important role in both the phase transition (α-FeOOH to Fe3O4) and the shape control. No substantial difference in the MR effect was observed between an octahedral-particle-based suspension and a spherical-particle-based one. Therefore, in this study, the shape of the microparticles did not strongly influence the MR effect, i.e., the properties of the chain structures.

ジャーナルInternational journal of molecular sciences
出版ステータスPublished - 2019 8月 1

ASJC Scopus subject areas

  • 触媒
  • 分子生物学
  • 分光学
  • コンピュータ サイエンスの応用
  • 物理化学および理論化学
  • 有機化学
  • 無機化学


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