Preparation of aluminum oxide-coated carbon nanotubes and the properties of composite epoxy coatings research

Multiwalled carbon nanotubes (MWCNTs) were acidized to get MWCNTs-COOH; the aluminum oxide (Al₂O₃)-coated MWCNTs hybrid material were prepared by sol–gel method and the result of cladding was verified using x-ray diffraction and scanning electron microscopy. Silane-coupling agent (KH560) was used to modify the hybrid materials. Composite coating with different concentrations of MWCNTs and Al₂O₃-coated MWCNTs was prepared. The wear resistance of the composite coating was tested by wear tester. The impedance performance and flexibility of Al₂O₃-coated MWCNTs/epoxy (2 wt%) and MWCNTs/epoxy (2 wt%, composite coating containing 2 wt% nanometer powder) were measured by the electrochemical workstation and mechanical testing equipment (MTS). The results show that the corrosion resistance and wear resistance of the Al₂O₃-coated MWCNTs/epoxy composite coating have some improvement compared with MWCNTs/epoxy, but a reduction in the flexibility of the Al₂O₃-coated MWCNTs/epoxy (2 wt%) composite coating.