Preparation, morphology, mechanical and electrical properties of TiO2 coated multiwalled carbon nanotube/epoxy composites

A titanium oxide (TiO2)-coated multiwalled carbon nanotube (MWCNT)/epoxy composite was prepared by coating MWCNTs with a layer of TiO2 and then modified with 3-(aminopropyl)triethoxysilane (APTES). The TiO2-coated MWCNTs and APTES-modified TiO2-coated MWCNTs (AT-MWCNTs) were analyzed by X-ray photoelectron spectroscopy. The AT-MWCNTs were added to the diglycidyl ether of bisphenol A-type epoxy to fabricate silane-grafted TiO2-coated MWCNT/epoxy composites. The amine functional groups on the AT-MWCNT surface react with the epoxy, improving the adhesion between the MWCNTs and epoxy. The morphological properties have been studied by TEM and SEM. The mechanical properties of the AT-MWCNT/epoxy composites dramatically exceeded that of the unmodified MWCNT/epoxy. However, since the MWCNTs were isolated by the TiO2, the volume electrical resistivity of the AT-MWCNT/epoxy composite exceeded that of the unmodified MWCNT/epoxy composites for a given amount of MWCNT added.