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.
YANG Guanghong ZHANG Xingtang XUN Jun JIANG Xiaohong ZHANG Pingyu DU Zuliang
