Preparation and characterization of carbon nanotubes/Al ₂ O ₃ inorganic hybrid material – A bio-inspired poly(dopamine) approach

Carbon nanotubes/alumina (CNTs/Al ₂ O ₃ ) nanocomposites were prepared by the poly(dopamine) assisted chemical liquid phase deposition (CLPD). The poly(dopamine) layers were firstly coated on the CNTs surface uniformly by the self-oxidative polymerization of dopamine in mild aqueous solution and then the Al ₂ O ₃ nanoparticles formed on the poly(dopamine) coated CNTs surface by the CLPD. The hydrophilic poly(dopamine) layers on the CNTs surface can improve the dispersion of CNTs in aqueous solution. Moreover, it can be used as a key linker between the CNTs and Al ₂ O ₃ because of the nitrogen-containing group in poly(dopamine) could coordinate with Al ³⁺ ions. The as-prepared poly(dopamine) coated CNTs and CNTs/Al ₂ O ₃ nano-hybrids were characterized by X-ray photoelectron spectroscopy(XPS), X-radial diffractometer(XRD) and high resolution transmission electron microscopy (HRTEM). These results showed that the poly(dopamine) layers were coated on the surface of CNTs uniformly, and the Al ₂ O ₃ nanoparticles embellished with the poly(dopamine) coated CNTs surface. Compared with pristine NR composites, the thermal conductivity of the as-prepared NR/CNTs@Al ₂ O ₃ composites increased 17%.