表面修饰银纳米颗粒的制备及摩擦学性能

以3-氨基-1,2,4-二噻唑-5-硫酮(ADTT)和均苯四甲酸酐为原料,在四氢呋喃溶液中,70℃下酰胺化反应合成了2,5-二(5-硫酮-1,2,4-二噻唑-3-甲酰胺基)-对苯二甲酸(BtdyTA),收率74%。以NaBH4为还原剂,在AgNO3水溶液中用液相化学还原法合成了表面修饰BtdyTA的银纳米颗粒,用透射电子显微镜(TEM)、傅里叶红外转换光谱仪(FTIR)和热分析仪(TG)对纳米颗粒的形貌、结构和热稳定性进行了表征,并在四球摩擦试验机上测试了表面修饰银纳米颗粒的抗摩减磨性能。结果表明,表面修饰的银纳米颗粒粒径分布均匀,平均粒径10nm左右,无团聚现象;在质量分数不大于5%时,可较好分散于液体石蜡等有机溶剂中,作为一种新的基础润滑油添加剂,可使摩擦系数减小32%,最小磨斑直径减小39%。

Preparation and Tribological Properties of Surface Modified Ag Nanoparticles

A new modification reagent named 2,5-bis(5-thione1,2,4-dithiazol-3-ylcarbamoyl)-terephthalic acid(BtdyTA),which was synthesized from 3-amino-1,2,4-dithiazole-5-thione(ADTT) and 1,2,4,5-benzenetetracarboxylic dianhydride by lactamization reaction in tetrahydrofuran in 74% yield.By liquid-phase deoxidization method,BtdyTA modified silver nanoparticles were synthesized with NaBH4 as reducing agent in AgNO3 solution.The morphology,structure and stability of BtdyTA-coated Ag(Ag-BtdyTA) nanoparticles were characterized with TEM,FTIR and TG.Anti-wear properties of Ag-BtdyTA nanoparticles were tested with a four-ball tribological testing machine.The results show that Ag-BtdyTA nanoparticles have a homogeneous grain distribution,and the average diameter is about 10 nm without reunion.When the mass fraction is less than 5%,Ag-BtdyTA nanoparticles can well distribute in organic solvents such as liquid paraffin.As a new kind of basic oil additive,Ag-BtdyTA nanoparticles can reduce the friction coefficient by 32%,and the minimum diameter of wear scar by 39%.