Fabrication of alumina filled hybrid buckypaper composites and their enhancement of microwave absorbing performance

Alumina (Al2O3)-filled multiwalled carbon nanotube buckypapers (BPs) with different Al2O3 loadings (5–50 wt%) were successfully synthesised. Structural and morphological analysis performed with x-ray diffraction and field-emission scanning electron microscopy, respectively, confirmed the presence of stable α -phase Al2O3 particles in the Al2O3-BP composites. The formation of flexible Al 2O3-BP hybrid nanocomposites (5–15 wt%) was attributed to the strong interfacial polarisation and high conductivity; compared with pure Al2O3 and BP. The nanocomposites with optimised alumina loadings demonstrated enhanced microwave absorption (>90%) and a broader absorption bandwidth in the investigated high-frequency region.