Investigation of the electrophysical properties of a composite material based on ABS plastic and functionalized carbon nanotubes for 3D printing of bipolar plates

Abstract

An electrically conductive filament based on acrylonitrile-butadiene-styrene (ABS) and functionalized single-walled carbon nanotubes (f-SWNTs) was developed and fabricated. The SWNTs were functionalized by acid treatment in an HNO₃/HCl mixture at 60 °C for 4 h, which allowed modification of the nanotube surface and improved their dispersion in the polymer matrix. Electrically conductive filaments with a diameter of 1.75±0.05 mm and an f-SWNT content of 0.05–1.5 wt.% were produced. Using the developed filament, a laboratory-scale bipolar plate (BPP) specimen with a gas distribution channel system was fabricated by fused deposition modeling (FDM). The dependence of the electrical conductivity of the samples on filler concentration was investigated using the four-probe method. The electrical percolation threshold of the ABS/f-SWNT system was approximately 0.1 wt.%, which was associated with the formation of a continuous conductive network at a low carbon nanotube content. The maximum electrical conductivity of 1.1×10–3 S/cm was achieved for samples containing 1.5 wt.% f-SWNTs and printed at the optimum temperature of 250 °C. The obtained results demonstrate the potential of the developed ABS/f-SWNT composite for rapid prototyping of BPPs for low-power electrochemical devices, including fuel cells and electrolyzers.