超高密度水基Fe_3O_4磁流体的制备及其性能表征

Preparation and Characterization of Water-Based Ultra-High Density Fe_3O_4 Magnetic Fluid

超高密度磁流体在航天、密封、矿物浮选领域有广阔的应用前景。采用化学共沉淀法经分离基液制备了超高密度Fe3O4水基磁流体。以XRD、TEM、振动样品磁强计（VSM）、旋转黏度计等对样品进行了表征。研究表明：高密度磁流体Fe3O4为反尖晶石型结构，平均粒径约15nm，其磁饱和黏度值、黏度变化域值、饱和磁化强度分别可达5．64Pa·S、0．82-5．64Pa·S、51．2emu·g^-1，分别是普通磁流体的564倍、60倍、7倍；饱和磁化强度随磁微粒含量的变化呈显著的线性相关性；当温度在20—80℃变化时，超高密度磁流体密度在4．9852-4．9827g·cm^-3，且与温度的变化基本无关。

Ultra-high density magnetic fluid has broad application prospects in the field of aerospace, sealing and mineral flotation. We using the method of chemical co-precipitation, prepared ultra-high density Fe3O4 magnetic fluid by separating redundant base solution. The samples were characterized by XRD, TEM, VSM and rotary viscometer. Results and their analysis showed preliminarily that ： （ 1 ） the Fe3O4 nanoparticles in the Ultra-high density magnetic fluid were inverse spinel structure with average particle size of 15 nm; （2） the viscosity in the saturated magnetic condition, viscosity range and saturation magnetization of the ultra-high density magnetic fluid achieved 5.64 Pa · S, 0.82-5.64 Pa · S, and 51.2 emu · g^-1, and they are respectively 564 times, 60 times, and 7 times those of the ordinary magnetic fluid; There is a significant linear correlation between the change of saturation mag- netization and the magnetic particle content; （3） when the temperature changed from 20℃ to 80℃, the density of the ultra-high density magnetic fluid changed merely from 4.985 2 g ·cm^-3 to 4.982 7 g · cm^-3.