Stability and low-temperature rheology of environmentally friendly vegetable composite oil-based Ni0.5Zn0.5Fe2O4 magnetic fluids
Vegetable oil as a base carrier fluid for nanomagnetic fluids suffers from the problem of poor cold flow behavior,and the addition of poly methacrylate is expected to reduce the pour point of vegetable oil and improve the low-temperature flowability of vegetable oil-based magnetic fluids.In this paper,a new environmentally friendly magnetic fluid was prepared by using Poly α Olefin(PAO-8)and corn oil as a composite base carrier flu-id,and poly methacrylate as a depressant to study the stability of its settling.The low-temperature flow proper-ties of the nanomagnetic fluids at different temperatures were investigated from the viewpoints of magnetic field,temperature,Ni0.5Zn0.5Fe2O4 mass fraction,PAO-8,and the addition of the depressant using a rotational viscometer.The results showed that the best settlement stability of the nanomagnetic fluids produced without surfactant,a mixture of 100 ml of corn oil and 25％of PAO-8 as the composite base carrier fluid,and Ni0.5Zn0.5 Fe2O4 mass fraction of 0.767％.The magnetic fluid with the addition of 0.5％poly methacrylate has better low-temperature flow properties and the pour point reaches-36 ℃.Under the condition of no magnetic field,when the temperature is lower than-25 ℃,the viscosity of the magnetic fluid increases abruptly with an exponential rising trend,and the low temperature fluidity of the magnetic fluid becomes worse;under the condition of mag-netic field,the viscosity of the nanomagnetic fluid is positively correlated with the magnetic field strength,and the viscosity curve changes significantly when the magnetic field strength is greater than 20 mT.The nanomag-netic fluid prepared in this paper has the characteristics of environmental protection and good low-temperature fluidity performance,which can be applied to low-temperature working conditions,and this study contributes to the further development of low-temperature applications of environmentally friendly magnetic fluids.
Environmentally friendly magnetic fluidComposite base carrier fluidCoagulant reductionSettling stabilityViscosity
NETL
NSTL
万方数据
