Self-assembled film containing the rare earth (RE) elements was formed on a silicon dioxide substrate, in order to reduce the surface adhesion and the f riction force of micro electro-mechanical systems (MEMS). The film thickness was measured as 2nm. The tribological experiment result shows that the friction coefficient of SiO2 substrate reduces from 0.5 to 0.1 after the formation of RE self-assembled film on its surface. Besides, RE self-assembled film exhibits a high wear resistant ance.

Polytetrafluoroethylene (PTFE) composites were prepared using 60 wt.% Pb and 5 wt.% glass fiber (GF). The surface of GF was modified with a coupling agent, a mixture of coupling agent and rare earths, and rare earths, respectively. The friction and wear properties of the PTFE composites, sliding against 45# carbon steel (AISI 1045 steel) under oil lubrication, were investigated on a pin-on-disc sliding wear machine. It was found that modified GF, which was filled into PTFE, decreased the wear of the PTFE composites compared with that of the PTFE composite filled with unmodified GF. The friction and wear properties of PTFE composite filled with Pb and rare earths-modified GF were greatly enhanced, owing to the effective improvement of the interfacial adhesion between the GF and PTFE.

Solutions of a rare-earth modifier (RES) and the epoxy chloropropane (ECP) grafting modification method are used for the surface treatment of F-12 aramid fibers. The effects of RES concentration on the interlaminar shear strength (ILSS) of F-12 aramid fiber/epoxy composites are investigated in detail, and the fracture surfaces of ILSS specimens are analyzed by SEM. It is shown that the RES surface treatment is superior to the ECP grafting treatment in promoting the interfacial adhesion between aramid fibers and the epoxy matrix. However, the tensile strength of single fibers is almost unaffected by the RES treatment. The optimum ILSS is obtained at a 0.5 wt.% content of rare-earth elements.

e measured. The fracture surface morphologies were observed and analyzed by SEM. The results indicate that rare earth elements can effectively promote the interfacial adhesion between the glass fiber and PTFE, owing to the effects of rare earth elements on the compatibility. The tensile properties of GFPPTFE composites can be improved considerably when the content of RE in surface modifier is 0.2 %～014%, and the optimum performance of GFPPTFE composites is obtained at 0.3 %RE content.