环保型植物复合油基Ni_(0.5)Zn_(0.5)Fe_(2)O_(4)磁流体的稳定性和低温流变性  

Stability and low-temperature rheology of environmentally friendly vegetable composite oil-based Ni_(0.5)Zn_(0.5)Fe_(2)O_(4)magnetic fluids

作　　者：龚湫 吴张永[1] 张刚[1] 朱启晨 蒋佳骏 GONG Qiu;WU Zhangyong;ZHANG Gang;ZHU Qichen;JIANG Jiajun(Faculty of Mechanical and Electrical Engineering,Kunming University ofScience and Technology,Kunming 650500,China)

机构地区：[1]昆明理工大学机电工程学院,昆明650500

出　　处：《功能材料》2024年第5期5195-5202,共8页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(51165012)。

摘　　要：植物油作为纳米磁流体基载液存在不良冷流动行为问题,聚甲基丙烯酸酯的添加有望降低植物油倾点和提高植物油基磁流体低温流动性。以聚α-烯烃(PAO-8)和玉米油作为复合基载液,以聚甲基丙烯酸酯为降凝剂,制备新型环保型磁流体,研究其沉降稳定性。从磁场、温度、Ni_(0.5)Zn_(0.5)Fe_(2)O_(4)质量分数、PAO-8、降凝剂添加量等角度,利用旋转粘度计研究了不同温度下纳米磁流体的低温流动性能。结果表明不采用表面活性剂、100 mL玉米油和25%的PAO-8的混合物作为复合基载液、Ni_(0.5)Zn_(0.5)Fe_(2)O_(4)质量分数为0.767%,制得的纳米磁流体沉降稳定性最佳。添加0.5%聚甲基丙烯酸酯的磁流体具有更好的低温流动性能,倾点达到-36℃。无磁场条件下,当温度低于-25℃时,磁流体黏度骤增,呈指数上升趋势,磁流体低温流动性变差;磁场条件下,纳米磁流体的黏度与磁场强度呈正相关,且磁场强度大于20 mT时黏度曲线变化明显。制备的纳米磁流体具有环保、低温流动性能好的特点,可应用于低温工况,研究有助于环保型磁流体低温应用的进一步发展。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 PolyαOlefin(PAO-8)and corn oil as a composite base carrier fluid,and poly methacrylate as a depressant to study the stability of its settling.The low-temperature flow properties of the nanomagnetic fluids at different temperatures were investigated from the viewpoints of magnetic field,temperature,Ni_(0.5)Zn_(0.5)Fe_(2)O_(4)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 Ni_(0.5)Zn_(0.5)Fe_(2)O_(4)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 magnetic 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 nanomagnetic 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.

关 键 词：环保型磁流体 复合基载液 降凝剂 沉降稳定性 黏度 

分 类 号：TB34[一般工业技术—材料科学与工程]