摘要
Composite C60-LB films were fabricated by the Langmuir-Blodgett (LB) technique, their micro- structures, micro- and macro-tribological properties were investigated using atomic force microscope/ friction force microscope (AFM/FFM). The results showed that in the confined C60-LB films there were two kinds of structures for the special C60 assembly: grain diameters of one kind were in the range of 150 -230 nm; the other was smaller than 20 nm. Mi- cro-tribological studies showed that topographical images of tiny C60 aggregates (<20 nm) were con- sistent with their frictional ones very well, namely, low friction occurred on tiny C60 aggregates compared with fatty chains LB monolayer, and ‘Micro-rolling effect’ was apparent; but for big large ones frictional forces were relatively high and ‘ratchet mechanism’ was seen apparently. Macro-tribological data proved large C60 aggregates had wear resistance and load-carrying capacities and anti-wear lives for com- posite C60-LB films were prolonged greatly with dis- persibility of C60 improved and its grain diameter re- duced. Tiny C60 aggregates were mainly the lubri- cating agents. Friction coefficients of composite C60-LB films gradually reduced with loads increasing having the same friction coefficient-load relations with boundary lubrication films.
Composite C60-LB films were fabricated by the Langmuir-Blodgett （LB） technique, their microstructures, micro- and macro-tribological properties were investigated using atomic force microscope/ friction force microscope （AFM/FFM）. The results showed that in the confined C60-LB films there were two kinds of structures for the special C60 assembly： grain diameters of one kind were in the range of 150 -230 nm; the other was smaller than 20 nm. Micro-tribological studies showed that topographical images of tiny C60 aggregates （〈20 nm） were consistent with their frictional ones very well, namely, low friction occurred on tiny C60 aggregates compared with fatty chains LB monolayer, and ‘Micro-rolling effect＇ was apparent; but for big large ones frictional forces were relatively high and ‘ratchet mechanism＇ was seen apparently. Macro-tribological data proved large C60 aggregates had wear resistance and load-carrying capacities and anti-wear lives for composite C60-LB films were prolonged greatly with dispersibility of C60 improved and its grain diameter reduced. Tiny C60 aggregates were mainly the lubricating agents. Friction coefficients of composite C60-LB films gradually reduced with loads increasing having the same friction coefficient-load relations with boundary lubrication films.
基金
supported by the National Natural Science Foundation of China(Grant Nos.90306010,20371015,and 20571024)
the Program for New Century Excellent Talents in University(Grant No.NCET-04-0653).
关键词
C60-LB
复合薄膜
聚合
摩擦性能
棘轮机构
composite C60-LB films, aggregates, tribological properties, Micro-rolling effect, ratchet mechanism
