Preparation and rheological properties of nano-composite magnetorheological fluids
The utilization of magnetic nanofluids as the base carrier fluid of magnetorheological fluids represents an effective approach to enhance the magnetorheological effect.However,achieving highly stable nano-compos-ite magnetorheological fluids remains a significant challenge,encompassing both the synthesis of magnetic nanofluids and the prevention of composite particle agglomeration.In this study,Fe3O4 silicone oil-based mag-netic nanofluids were prepared using silane coupling agent KH550 as a dispersant,followed by a novel process of co-coating dispersants to obtain nano-composite magnetorheological fluids.The surface morphology,physical phase composition and magnetic properties were characterized and analyzed using XRD,FI-IR,TEM,FE-SEM and VSM.The sedimentation stability and redispersibility of the novel nano-composite magnetorheological fluids were investigated.The results show that surface modification of micron-sized particles significantly enhances the stability and redispersibility of the nano-composite magnetorheological fluids,with optimal sedimentation sta-bility and redispersibility observed at nanoparticle volume fraction of 8％.Furthermore,the novel nano-compos-ite magnetorheological fluids demonstrate superior temperature resistance,remaining stable within the tempera-ture range form-40 ℃ to 120 ℃ over extended durations.Rheological properties of novel nano-composite mag-netorheological fluid were also investigated demonstrating higher off-state viscosity and magnetorheological effect in comparison to conventional magnetorheological fluids.Moreover,both static and dynamic yield stresses increase with nanoparticle concentration and magnetic field strength.
万方数据
维普
