离子液体掺杂硅油薄膜的制备及其摩擦学性能研究

Preparation and Tribological Behavior of Silicone Films Doped with Ionic Liquid

采用旋涂方法,利用硅油热交联反应在不同基底上制备了掺杂离子液体的硅油薄膜,用红外光谱仪表征了硅油薄膜的交联聚合行为,用DF-PM型静-动摩擦磨损试验机评价了薄膜的摩擦学性能,采用扫描电子显微镜观察分析了薄膜及偶件磨损表面形貌.结果表明,在甲基化和羟基化基底表面制备的薄膜的摩擦学性能较差,而在乙烯基化基底表面制备的薄膜同钢球对摩时表现出很好的摩擦学性能,这主要是由于乙烯基化基底表面的薄膜可通过交联聚合反应而同基底形成较强的化学键合作用所致.在滑动摩擦过程中,薄膜的摩擦系数随速度增加而减小,这是由于相对较厚的润滑薄膜发生剪切变稀效应所致.

The silicone films chemically modified with ionic liquids on single crystal Si and/or glass slide substrates with different terminals were prepared making use of spin-coating technique. The polymerization and/or crosslinking in the silicone film on vinyl-terminated substrate were examined by means of Fourier transformation infrared spectroscopy. The tribological properties of the films sliding against AISI-52100 steel ball in a ball-on-plate configuration were investigated using a dynamic static friction coefficient measurement apparatus. The morphologies of the wear tracks of bare substrate, the composite films, and the counterparts were observed using a scanning electron microscope. It was found that the composite films on the hydroxyl-terminated and methyl-terminated substrates showed poor tribological properties, while the films on the vinyl-terminated substrate exhibited excellent tribological behavior. It was presumed that there was chemical bond between the crossed-link film and the vinyl-terminated substrate, which contributed to increase the bonding strength between the composite films and the substrate and hence improved the friction and wear behavior of the composite films. The decrease of the friction coefficient at a large enough sliding velocity was related to the shear thinning effect of the composite film thereat.