润滑膜全氟聚醚的稳定性  

Stability of lubricant perfluoropolyether films

作　　者：李欣[1] 胡元中[1] 王慧[1] 陈辉[1] 

机构地区：[1]清华大学摩擦学国家重点实验室,北京100084

出　　处：《物理学报》2007年第7期4094-4098,共5页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:50390060);国家重点基础研究发展规划(批准号:2003CB716201);高等学校博士学科点专项科研基金(批准号:20060003025)资助的课题.~~

摘　　要：采用基于粗粒珠簧模型的分子动力学模拟方法,考察了非极性和极性全氟聚醚(perfluoropolyether,PFPE)膜在固体表面的稳定性.随着时间推移,非极性PFPE膜的表面形貌没有明显变化,呈现稳定的状态;而强极性PFPE膜的部分润滑分子发生局域集聚,使润滑膜的表面粗糙度随时间而增大,呈现不稳定的状态.通过比较具有不同极性端基PFPE润滑膜的表面形貌变化,结果发现:极性端基与极性端基的作用是导致润滑膜不稳定的根本原因,极性端基与固体表面的作用对润滑膜稳定性影响不大.Molecular dynamics simulations based on a coarse-grained, bead-spring model are adopted to investigate the stability of both nonfunctional and functional perfluoropolyether （PFPE） on solid substrates. For nonfunctional PFPE, the surface morphology changes little with time. The film is stable. For functional PFPE, part of lubricant molecules show local dewetting which causes the increase of surface roughness with time. The film is unstable. Besides, the changes in surface morphology with different endbeads are compared, which indicate that the endbead-endbead interaction is the principal reason for the film instability and the endbead-substrate interaction has little effect on the film stability.

关 键 词：全氟聚醚膜 分子动力学模拟 稳定性 

分 类 号：O313.5[理学—一般力学与力学基础]