Portal de Periódicos da CAPES

Highly conductive multiwall carbon nanotube and epoxy composites produced by three-roll milling

2009; Elsevier BV; Volume: 47; Issue: 8 Linguagem: Inglês

10.1016/j.carbon.2009.03.039

1873-3891

I.D. Rosca, Suong V. Hoa,

Conducting polymers and applications

Length and diameter distributions as well as the conductivity of bucky papers made of different multiwalled carbon nanotubes (MWCNTs) have been measured. While the average diameter is in good agreement with the manufacturer specification, the average length is significantly shorter than that given by the manufacturer. Highly conductive and homogeneous dispersions of up to 8 wt% MWCNTs in an epoxy resin are obtained by three-roll milling. The influence of shear intensity and number of passes on the nanotube dispersion and composite conductivity is investigated. The aspect ratio of the MWCNTs is one of the most important parameters that determine the composite conductivity and the percolation behavior. We have found that the composite conductivity increases almost 10 times as the aspect ratio increases 5.5 times. The percolation parameters in conjunction with the optical microscopy revealed a kinetic rather than statistic percolation. We have observed that three-roll milling induces extended alignment of MWCNTs with high aspect ratio at moderate loading (2–4 wt%).