Improved thermooxidation and sedimentation stability of covalently-coated carbonyl iron particles with cholesteryl groups and their influence on magnetorheology

0395196 - ÚH 2014 RIV US eng J - Journal Article
Mrlík, M. - Ilčíková, M. - Pavlínek, V. - Mosnáček, J. - Peer, Petra - Filip, Petr
Improved thermooxidation and sedimentation stability of covalently-coated carbonyl iron particles with cholesteryl groups and their influence on magnetorheology.
Journal of Colloid and Interface Science. Roč. 396, april (2013), s. 146-151. ISSN 0021-9797. E-ISSN 1095-7103
R&D Projects: GA ČR GA202/09/1626
Grant - others:GA MŠk(CZ) ED2.1.00/03.0111
Institutional support: RVO:67985874
Keywords : covalent coating * carbonyl iron * cholesteryl chloroformate * thermooxidation * Magnetorheology
Subject RIV: BK - Fluid Dynamics
Impact factor: 3.552, year: 2013

Sedimentation of particles in magnetorheological suspensions represents a crucial problem that concerns their efficient long-term application in practice. Prepared carbonyl iron (CI) microparticles coated with a low density substance, cholesteryl chloroformate, via a two-step reaction and immersed in silicone oil, exhibit three positive aspects: (1) the CI particle modification increased the compatibility between the particles and the silicone oil resulting in improved long-term stability (reduction in sedimentation); (2) the coating provided the particles with enhanced thermal stability in the oxygen atmosphere; and (3) rheological measurements proved a promising magnetorheological performance at different particle weight fractions.
Permanent Link: http://hdl.handle.net/11104/0231146