纳米二硫化钨颗粒的分散稳定性

Dispersion stability of nano-tungsten disulfide particulates

为了提高纳米二硫化钨颗粒在润滑油中的分散稳定性,采用超声波分散、机械搅拌分散和颗粒表面修饰三者相结合的方式来处理纳米二硫化钨颗粒,通过沉降法、粒度分布法和显微镜法评价其分散效果;通过滴定法和红外光谱分析研究纳米二硫化钨颗粒在润滑油中的分散机理;最后考察纳米二硫化钨颗粒对磨损表面的修复效应。研究结果表明:在超声波和机械搅拌作用下,表面修饰后的纳米二硫化钨颗粒在润滑油中未形成大团聚体,能均匀且稳定地分散于润滑油中;表面修饰剂与纳米二硫化钨颗粒表面羟基作用,使颗粒表面吸附大量长链亲油基团,这些长链亲油基团充分伸展于润滑油中,并形成位阻层,阻碍颗粒的碰撞团聚和重力沉降,从而使得纳米二硫化钨颗粒能稳定分散于润滑油中;而稳定分散与润滑油中的纳米二硫化钨颗粒在摩擦过程中能在磨损表面形成有效的保护膜,对磨损表面起到很好的修复作用。

In order to improve the dispersion stability of nano-tungsten disulfide in lubricating oil, nano-tungsten disulfide particulates were treated by the combinative method of ultrasonic dispersion, mechanical agitation and surface modification, the settlement speeds, size distributions and microscope pictures of particulates in oil were tested to evaluate the dispersion effect, and dispersion principle of nano-tungsten disulfide in lubricating oil was studied through the analysis of titration and infra-red spectrum. Finally, the repair action of nano-tungsten disulfide to abrasive surfaces was studied. The results show that affected by ultrasonic and mechanical agitation, surface modified nano-tungsten disulfide particulates don＇t form big glomeration and disperse in the lubricating oil evenly and stably. Meanwhile, surface modifier can react with hydroxide radicals on surfaces of nano-tungsten disulfide particulates, making particulates＇ surfaces adsorb many lipophilic groups with long chains, which can stretch in the oil adequately and form steric hindrance layers that stop particulates from conglomerating and depositing, leading to nano-tungsten disulfide particulates＇ stable dispersion in lubricating oil. And moreover, the nano-tungsten disulfide particulates which disperse in the lubricating oil stably can form effectual protective films on abrasive surfaces in the course of friction and repair the abrasive surfaces well.