改性生物柴油碳烟的制备、表征及水基润滑特性

为了探索生物柴油碳烟(BDS)作为水基润滑添加剂的应用, 采用热氧化法制备了热氧化处理的BDS(TO-BDS); 通过场发射透射电子显微镜、 X射线光电子能谱仪和Zeta电位仪等表征了TO-BDS的形貌、 组成和分散性, 并与BDS进行了对比; 利用球-盘往复摩擦磨损试验机、 3D激光扫描显微镜、 场发射扫描电子显微镜、 光学法接触角/界面张力仪和拉曼光谱仪考察了含TO-BDS的纯水(H₂O)的摩擦磨损性能和润滑机理. 结果表明, TO-BDS表面的含氧官能团和负电荷比BDS更多, 从而导致TO-BDS在H₂O中具有更好的分散性; 在H₂O中添加质量分数为0.2%的TO-BDS, 可显著改善H₂O的减摩抗磨性能. 这主要是因为在摩擦过程中, TO-BDS起到滚动轴承的功效, H₂O+TO-BDS比H₂O在摩擦副表面的润湿性能更好, 更易于形成润滑膜且TO-BDS会因摩擦力诱导剥离产生石墨片, 从而降低摩擦磨损.

Preparation,Characterization and Water-based Lubricity of Modified Biodiesel Soot †

In order to realize the utilization of biodiesel soot(BDS) as lubricant additives in water, thermally oxidized biodiesel soot(TO-BDS) was prepared by thermal oxidation. The morphology, composition and dispersion of TO-BDS were analyzed by field-emission transmission electron microscopy, X-ray photoelectron spectroscopy and zeta potentiostat, and compared with that of BDS. The tribological properties and the lubricant mechanism of TO-BDS as an additive in water were investigated using a ball-on-disc reciprocating tribometer, 3D laser scanning microscopy, field-emission scanning electron microscopy, optical contact angle/interface tension meter and Raman spectrometer. Results indicate that the oxygen-containing functional groups and negative charges of TO-BDS are more than that of BDS, which leads to better dispersion of TO-BDS in water compared with BDS in water. The anti-friction and anti-wear properties are significantly improved after adding 0.2%(mass fraction) TO-BDS in water. The main reason is that TO-BDS can act as bearing during friction process and water containing TO-BDS is more facile than water to form lubricating film because the friction pairs are more wettable for water containing TO-BDS in comparison with water. Besides, it also can reduce friction and wear due to friction induced the exfoliating graphitic sheets of TO-BDS.