Silane treatment of carbon nanotubes and its effect on the tribological behavior of carbon nanotube/epoxy nanocomposites.

Functionalization of carbon nanotubes (CNTs) influences dispersion and interfacial strength in CNT-reinforced nanocomposites. In this study, multi-walled CNTs were functionalized via oxidation with a mixture of sulfuric acid (H2SO4) and nitric acid (HNO3). Then, the functionalized CNTs with oxidation were surface-modified using a coupling agent, 3-aminopropyltriethoxysilane. CNT/epoxy nanocomposites were fabricated using oxidized CNTs and silane-modified CNTs, respectively, to investigate the effect of silane treatment on the tribological behavior of CNT/epoxy nanocomposites. Wear tests were performed on oxidized and silanized CNT/epoxy nanocomposites, at three different sliding speeds. The results showed that the friction coefficient and wear rate of silanized CNT/epoxy nanocomposites were lower than those of oxidized CNT/epoxy nanocomposites, regardless of sliding speed. The improved tribological behavior of silanized CNT/epoxy nanocomposites occurred due to the improved dispersion of CNTs into the epoxy and improved adhesion with the epoxy.