研究了油酸(OA)、硬脂酸(SA)和12-羟基硬脂酸(HSA)3种分散剂修饰的纳米铋粉在基础油500SN中的悬浮稳定性能。利用酸碱滴定、红外光谱测量和表征了3种分散剂在粉体表面的吸附量及吸附状态。研究结果表明:油酸及硬脂酸对粉体表面的修饰作用主要为化学吸附,12-羟基硬脂酸主要为物理吸附;悬浮液的分散稳定性能随着分散剂在粉体表面吸附量的增多而增强,12-羟基硬脂酸在纳米铋粉表面吸附量最大,其悬浮稳定性能最好,其次为硬脂酸,最后为油酸。
Three types of fatty acids, oleic acid, stearie acid and 12-hydroxystearic acid, were used to modify the surface of nanometer bismuth powder surface in octane solvents. The stability of the suspension was measured by free sedimentation when the surface modified powders were put into base oil 500SN, and characterized by infra-red spectrum. Experimental results indicate that the function of oleic acid and steaxie acid to the powder surface modification is mainly chemical adsorption, while the 12-hydroxystearic acid is mainly physical adsorption. The dispersion stabilization of the suspending increases with increasing the adsorptive capacity of fatty acid in the powder surface ,as 12-hydroxystearic acid has the largest adsorptive capacity on the nanometer bismuth powder surface, it has the best suspension stability, the next is stearic acid.