表面修饰剂的亲油链长度对纳米氟化镧摩擦学性能的影响

Effect of Length of Surface Modifier Lipophilic Chain on Tribological Properties of LaF_3 Nanoparticles

以亲油基链长度不同的十二酸二乙醇胺、十四酸二乙醇胺、十六酸二乙醇胺及十八酸二乙醇胺为表面修饰剂,在醇-水体系中制备了4种纳米氟化镧粒子,通过透射电镜(TEM)、红外光谱(FTIR)、热重仪(TG)研究了纳米氟化镧粒子的形貌及表面修饰情况,利用四球机研究了亲油链长度对纳米氟化镧粒子的摩擦学性能及对基础油感受性的影响。结果表明:随着表面修饰剂烷基链长度的增长,纳米LaF3粒子在基础油中摩擦学性能呈现出逐渐增强的趋势;亲油链越长,纳米粒子在液体石蜡中的摩擦学感受性比500SN基础油中更好。这主要是因为亲油基链的长度影响了纳米粒子的界面活性,而且同系有机酸皂类物质,亲油基碳链越长,其减摩作用也越好;基础油的性质影响了纳米粒子的界面活性。

Surfaee modifiers with different lipophilie chain lengths, such as laurie acid diethanolamine, myristie acid diethanolamine, palmitie acid diethanolamine and stearie acid diethanolamine, were used to prepare four kinds of LaF3 nanoparticles in the mixture solvent of water-ethanol. Morphology and surface modification of LaF3 nanopartieles were investigated by TEM, FTIR and TG. Effect of the length of surface modifier lipophilie chain on tribologieal properties of LaF3 nanopartieles and their susceptibility to base oils were investigated by a four-ball machine. Results show that the tribologieal properties of LaF3 nanopartieles in the base oil are increased with the increase of lipophilie chain length of surface modifiers ; the longer the lipophilie chain is, the better the susceptibility of the nanopartieles to liquid paraffin wax is. This is mainly because of the lipophilie chain length influences the interface activity of the nanopartieles, moreover, for homologous organic acid soaps ,the longer the lipophilie chain is ,the better its friction reducing performance is; the properties of base oils also influence the interface activity of the nanopartieles.