Rheological behavior of multiwall carbon nanotubes with polyelectrolyte dispersants

The rheological behavior of multiwall carbon nanotubes (MWCNTs) with polyelectrolyte dispersants (poly(acrylic acid) and poly(aspartic acid)) was investigated. The zeta potential of MWCNT slurries with adding dispersants and the optimum amount of dispersants for MWCNT slurries were measured. The Krieger–Dougherty equation was fitted to experimental data with varying solid loadings. The fitted results of MWCNT slurries showed the high intrinsic viscosity and the low maximum solid loading because of the high aspect ratio and the strong van der Waals force of MWCNTs. Poly(acrylic acid) stabilized MWCNT slurries had a lower maximum solid loading and a higher intrinsic viscosity (ϕm = 0.16, [η] = 43) compared to poly(aspartic acid) stabilized MWCNT slurries (ϕm = 0.21, [η] = 41.47). These differences may be caused by the different chemical structures of dispersants.