SiO_2空心微球的制备表征及摩擦性能

Preparation and characterization of silica hollow microspheres and tribological behavior

以分散聚合法制备的聚苯乙烯(PS)微球为有机模板,以正硅酸四乙酯(C8H20O4Si)为无机前躯体物料,通过静电吸附作用成功地制备了纳米PS-SiO2复合微球和SiO2单分散空心结构。通过红外(FTIR)、热重(TG)、透射电镜(TEM)、扫描电镜(SEM)和热重分析仪(TGA)等手段对纳米复合材料进行了表征,并对产物的抗磨性能进行了测试。结果表明,该方法可一次性制备大量的复合微球,这些微球的直径约为0.7μm,分散性能良好。在煅烧去除模板后,得到了保持完整的空心纳米SiO2结构,微球的球壳稳定性较好。摩擦实验表明,添加了2 wt%空心微球的植物油在较低载荷工况下具有优异的减磨性能,摩擦系数可低至0.058。

PS-SiO2 composites and SiO2 hollow spheres were successfully prepared by using polystyrene（PS） particles as templates and tetraethoxysilane as precursors.The silica shells were coated on the surfaces of template via electrostatic interaction.Fourier transform-infrared spectroscopy,thermo-gravimetric analysis,transmission electron microscopy,and scanning electron microscope measurements were used to characterize these hollow silica spheres.Their tribological properties were also investigated.The results show that large quantity of monodispersed PS-SiO2 composites with a diameter of about 0.7 μm can be obtained in this process.After the calcination treatment,the templates were removed and SiO2 hollowspheres were perfectly retained.The friction experiment was made at UMT-2（CETR） and it could be concluded that the base oil with 2 wt% prepared SiO2 nanostructures had better friction reduction than those with pure oil.The friction coefficient can be reduced to about 0.058 in low load.