Preparation and tribological properties of lanthanum-doped TiO_2 nanoparticles in rapeseed oil

作     者：谷科城 陈波水 陈勇 

作者机构：Department of Oil Application & Management EngineeringLogistical Engineering University Department of Barracks Management & Environmental EngineeringLogistical Engineering University 

出 版 物：《Journal of Rare Earths》 (稀土学报（英文版）)

年 卷 期：2013年第31卷第6期

页      面：589-594页

核心收录：

学科分类：0709[理学-地质学] 0819[工学-矿业工程] 07[理学] 070205[理学-凝聚态物理] 0708[理学-地球物理学] 0703[理学-化学] 070301[理学-无机化学] 0702[理学-物理学] 

基　　金：supported by National Natural Science Foundation of China(50975282) 

主　　题：titanium dioxide lanthanum nanoparticle preparation rapeseed oil lubricant additive tribological properties rare earths 

摘      要：Oleic acid （denoted as OA） surface-capped lanthanum-doped titanium dioxide composite nanoparticles, abbreviated as OA/La-TiO2, were prepared via sol-gel method in association with surface modification by oleic acid. The microstructure of as-prepared OA/La-TiO2 was characterized by means of X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectrometry, and their thermal stability was evaluated by thermogravimetry and differential scanning calorimetry. Moreover, the tribological properties of OA/La-TiO2 as lubricant additives in rapeseed oil were evaluated with a four-ball friction and wear tester. The morphology as well as elemental composition and chemical characteristics of worn steel surfaces was investigated by scanning electron microscopy, energy dispersive X-ray spectrometry and X-ray photoelectron spectroscopy. Results showed that as-prepared OA/La-TiO2 particles were of spherical shape and had an average diameter of 20 nm. In the meantime, OA/La-TiO2 particles doped with 1.5% （molar ratio; the same hereafter） and 2.5% of lanthanum could markedly improve the anti-wear and friction-reducing capacities of rapeseed oil. This is attributed to the formation of a complex boundary lubrication film mainly composed of the oxides of iron, titanium and lanthanum as well as the formation of an adsorption film of oleic acid on steel sliding surfaces.