Electric field enabled manipulation of CNT alignment in epoxy matrix: Methodology and mechanical characterization

The alignment of carbon nanotubes (CNTs) in polymer matrix is an effective way to utilize their anisotropic properties. In this study, a CNT alignment methodology based on the use of a non-uniform electric field is presented. The manipulation of CNT behaviour in an epoxy matrix was accomplished based on the principle of dielectrophoresis. The effectiveness of the technique was assessed by determining the tensile strength and fracture toughness (KIC) of aligned CNT/epoxy composites samples prepared using this method. Tensile tests revealed an increase in tensile strength of nanocomposites with increasing CNT loading content up to 0.1 wt.% CNT. A ~ 27 % increase in tensile strength in CNT nanocomposite samples containing 0.1 wt.% CNTs with respect to that of neat resin was observed. The fracture toughness values were also observed to increase with increasing CNT loading content. A ~ 50 % increase in KIC value in nanocomposites containing 0.5 wt.% CNTs was observed as compared to that of neat resin. The results indicate that the method can be effectively used to preferentially align CNTs in a polymer matrix.