Pickering emulsion polymerized poly(N-methylaniline)/Fe3O4 nanocomposite particles and their dual electrorheological and magnetorheological responses

초록

Core-shell structured nanocomposite particles with electric/magnetic dual-responsive characteristics were synthesized using a Pickering emulsion polymerization process, in which magnetite (Fe3O4) nanoparticles served as a solid particle surfactant for the shell structure, and poly(N-methylaniline) (PNMA) was used as the core structure. In addition to various characterizations of their morphology, chemical and crystalline structures, magnetic and thermal properties, the synthesized PNMA/Fe3O4 particles were dispersed in silicone oil to prepare a suspension, and their magnetorheological and electrorheological (ER) properties were investigated using a rotational rheometer. While PNMA does not require a de-doping step for its ER application compared to typical conducting polymers, the suspension exhibited solid-like properties under the action of external electric and magnetic fields with a yield stress of 126.75 Pa under an electric field of 2.5 kV/mm, and 38.88 Pa under a magnetic field of 171kA/m. The yield stresses were directly proportional to the magnetic/electric field strength with slopes of 1.0 and 2.0, respectively.

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