Page 109 - 《摩擦学学报》2020年第6期

第 40 卷 第 6 期 摩 擦 学 学 报 Vol 40 No 6
2020 年 11 月 Tribology Nov, 2020

DOI: 10.16078/j.tribology.2019231

聚合物PLL-g-PEG构象变化对宏观

摩擦学性能的影响

1,2
2*
1
杨淑燕 , 李 栋 , 吴 杨 , 郭 峰 1*
(1. 青岛理工大学 机械与汽车工程学院，山东 青岛 266520;
2. 中国科学院兰州化学物理研究所 固体润滑国家重点实验室，甘肃 兰州 730000)
摘 要: 通过将聚赖氨酸-聚乙二醇(PLL-g-PEG)加入至不同体积分数的HEPES-甘油混合溶液中来改变聚合物的构
象，研究其构象变化对摩擦性能的影响. 利用晶体微量天平(QCM)定量表征了不良溶剂(甘油)的加入所导致聚合物
刷构象发生的改变；摩擦试验结果表明在良性溶剂(HEPES)中聚合物刷高度水化作用对于摩擦磨损性能的改善起
主导作用，而不良溶剂中起决定作用的是甘油的黏度效应；利用纳米级光干涉薄膜测量装置试验证实了表面修饰聚
合物刷后的钢球-玻璃盘界面间的成膜特性既与聚合物刷的构象变化相关，也与流体动压效应相关，且随卷吸速度
的改变二者对接触区内成膜的贡献会发生转变；对二者共同作用下的水基润滑机理进行了初步探讨，这对于拓宽水
基润滑的应用具有较为重要的意义.
关键词: 聚合物PLL-g-PEG; 构象变化; 水基润滑机理; 黏度效应; 水合效应
中图分类号: TH117.2 文献标志码: A 文章编号: 1004-0595(2020)06–0792–09

Effect of Polymer PLL-g-PEG Conformation on

Macro-Tribological Properties

1,2 1 2* 1*
YANG Shuyan , LI Dong , WU Yang , GUO Feng
(1. School of Mechanical Engineering, Qingdao Technological University, Shandong Qingdao 266520, China
2. State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy
of Sciences, Gansu Lanzhou 730000, China)
Abstract: It was designed to change polymer conformation by adding poly(L-lysine)-g-poly(ethylene glycol) (PLL-g-
PEG) to 3 HEPES-glycerol solutions mixed with different volume ratio glycerol in this work for studying the effect of
polymer conformation on tribological performance. Conformation change of polymer PLL-g-PEG was quantitatively
characterized. Quartz Crystal Microbalance (QCM) was used to quantitatively characterize the change of polymer brush
conformation with the addition of poor solvents. The results showed that the highly hydration effect of polymer brushes
in good solvents played a critical role in improving the friction and wear, while the viscosity effect of glycerol was
dominated in poor solvents. It was verified by nano-scale optical interference thin film measurement device that film-
forming properties in the gap between the steel ball and glass disk, which were both grafted by polymer brush, was
determined by both hydration effect induced by conformational change of the polymer brush and hydrodynamic effect.
And the influence of hydration effect and hydrodynamic effect on film formation in contact changed with entrainment
velocity. The water-based lubrication mechanism under the combined effect of the two was preliminary probed, which
was very important for broadening the application of water-based lubrication.

Received 22 November 2019, revised 14 April 2020, accepted 17 April 2020, available online 28 November 2020.
*Corresponding author. Email: yangwu@licp.cas.cn; mefguo@qut.edu.cn, Tel: +86-532-68052755.
The project was supported by the National Natural Science Foundation of China (51775287, 51605470) and State Key Laboratory of
Solid Lubrication Fund (LSL-1712).
国家自然科学基金项目(51775287，51605470)和国家固体润滑重点实验室开放基金项目(LSL-1712).