Polymer Modification of Ultrafine Metal Iron Particles and Magnetorheological Properties of Their Suspensions

Monodispersed polymer modified metal iron particles have been synthesized by y-ray radiation. Selecting cetyltrimethyl ammonium bromide (CTAB), sodium dodecyl sulfonate (SDS),Tween-80, TritonX-200 and OP-10 as emulsifiers respectively. Several emulsions containing organic monomers and iron particles were obtained. By comparing stability of these emulsions,we selected a more suitable emulsifier, TritonX-200. Polymer modified iron particles were characterized by XRD, TEM and IR. In addition, pure iron particles and polymer modified iron particles were dispersed into mineral oil respectively to form magnetorheological fluids and their differences in suspension properties have also been investigated. The differences in magnetorheological measurement between suspension of Fe-copolymer particles and Fe3O4-PMMA composite particles have been studied. Experimental results showed that this kind of suspension with Fe-copolymer particles dispersed will become a new type of magnetorheological materials.