Fabrication and Characterization of Nanocomposite Films

Carbon nanotubes (CNT) with superior mechanical, electrical and thermal properties are excellent candidates for nano-reinforcing polymer-based composites. In this work, the multi-walled carbon nanotubes (MWCNT) reinforced epoxy films were prepared on the bakelite substrate by a hot-pressing process. To control the thickness of the film, a spacer of thickness 200 urn was employed. The analytical relationship among the moduli of the film, substrate and film/substrate system was derived basing on the beam theory, from which the elastic modulus of the film was determined by the three-point-bending test. Compared to neat resin films, an increase of 16% and 33% in elastic modulus were obtained when 1 wt% and 2 wt% of MWCNTs were added, respectively. Nanoindentation tests were employed to determine the hardness and Young's modulus of the film in the nanometric scale. The measured hardness and Young's modulus of the nanocomposite film were found to depend on the penetration depth. Experimental results show that the hardness and Young's modulus of the film were decreasing with the increase of the indentation depth.