Dispersion of multi-walled carbon nanotubes mechanically milled under different process conditions

Abstract

In order to maximize the performances of carbon-nanotube-based composites, it is very important to exactly understand the factors that affect the dispersion of carbon nanotubes. In this study, the milling treatment conditions that resulted in optimal dispersion were determined by analyzing the correlations between important dispersion process factors. In general, as the milling time increased, the diameters, bundle lengths, and bundle diameters of the aggregates decreased. Further, the optimal milling time was 6 h. On the other hand, the bulk density increased with the milling time, indicating that the paste viscosity properties improved gradually. In addition, the electrical conductivities were measured after the extrusion evaluation tests for composites of multi-walled carbon nanotubes and a polymer; 6-h-milled samples provided the lowest surface resistance values, showing the optimum dispersion effect.