Preparation and characterization of thermoconductive polymer nanocomposite with branched alumina nanofiber

A highly thermoconductive resin with branched filler is reported. The filler was fabricated by calcination of aluminium isopropoxide adsorbed onto paper filter (cellulose fibers). Scanning electron microscopy and x-ray diffraction measurement demonstrated that the filler consists of alpha-alumina nanofiber with a branched structure. The thermal conductivity of the filler-resin nanocomposite was two to five times larger than that predicted by the well-known Bruggeman equation, which postulates the composite with spherical filler in the matrix. The branched shape of the alpha-alumina nanofiber increased the probability of formation of phonon paths with lower thermal resistance, leading to the high thermal conductivity of the nanocomposite. (C) 2008 American Institute of Physics.