Abstract: Naphthenic base nanolubricants with good stability were prepared by modifying nano graphite in two forms with silane coupling agent KH570. An oscillating densitometer and a rotary viscometer were used to test the density and viscosity of graphite nanolubricants with mass fraction of 0.05%, 0.1%, 0.2%, 0.5%, 1%, 1.5%, and 2% in a temperature range from 288 K to 343 K. The results show that the density and viscosity of graphite nanolubricants increase with the increase of nanoparticle mass fraction. The densities of nanolubricants adding plate-shape graphite are higher than those with spherical graphite at the same mass fraction, while the viscosity shows opposite trend. The viscosity increases obviously at the temperature higher than 313 K with spherical graphite added. Correlations for the density and viscosity are developed as a function of nanoparticle concentration, particle size and shape. The correlation for density agrees well with experimental results, with 90% of the viscosities predicted within ±5% deviation from the measurement.

Key words: nanoparticles, surfactant, density, viscosity, particle size, correlation

摘要： 采用硅烷偶联剂KH570对两种形态的纳米石墨进行表面改性，配制了稳定性良好的环烷基纳米冷冻机油。利用振荡密度仪和旋转黏度计对纳米石墨冷冻机油（纳米石墨为粒状和片状，质量分数为0.05%、0.1%、0.2%、0.5%、1%、1.5%、2%）在不同温度（288～343 K）下的密度和黏度进行了测试。结果表明：纳米石墨冷冻机油的密度和黏度随着纳米颗粒浓度的增加而增大；相同浓度下添加片状石墨的纳米冷冻机油密度大于粒状，添加粒状石墨的纳米冷冻机油黏度大于片状，且在温度高于313 K时黏度也有明显上升；基于纳米石墨的浓度、粒径及形态开发了密度和黏度关联式，其中密度计算值与实验数据基本吻合，黏度计算值与90%的实验数据偏差在±5%以内。

关键词: 纳米粒子, 表面活性剂, 密度, 黏度, 粒径, 关联式