Fabrication of liquid crystal Fe3O4 composites and their magnetorheological properties

Abstract Some supramolecular polyacrylate‐based liquid crystal polymers (PLCPs) were prepared by polyacrylic acid, a liquid crystal monomer and 3,5‐pyridinedicarboxylic acid. Series of magnetic liquid crystal particles (Fe 3 O 4 @PLCPs) with core‐shell structure were prepared by modifying surface of magnetic nanoparticles Fe 3 O 4 by the PLCPs. The Fe 3 O 4 @PLCPs showed a saturation magnetization strength above 51.17 emu/g, which is similar to pure magnetic Fe 3 O 4 , indicating good magnetism and magnetic field dependence. Series of magnetorheological fluids were fabricated by Fe 3 O 4 @PLCPs (using as dispersed phase) and silicone oil (using as carrier liquid). The effects of mesogen, magnetic particle, and the polymer matrix on magnetorheological performance and settling stability were investigated. The magnetorheological fluid based on 10% Fe 3 O 4 @PLCP‐1 showed the best performance at an applied magnetic field of 100 mT in this study. Furthermore, the magnetorheological fluids showed excellent settling stability because the density of Fe 3 O 4 @PLCPs was lower than that of Fe 3 O 4 . The Fe 3 O 4 @PLCPs‐based fluids presented certain application potential in the field of magnetic fluid due to the excellent magnetorheological effect and settling stability.