Aligned single-wall carbon nanotubes in composites by melt processing methods

TLDR

The study reports producing SWNT–polymer composites with improved mechanical and electrical properties and exceptional nanotube alignment. The authors dispersed SWNT in PMMA via solvent casting and melt mixing, then melt‑spun fibers to achieve draw ratios of 20–3600. The resulting composites exhibited higher conductivity along the flow direction, increased elastic modulus and yield strength with higher nanotube loading and draw ratio, and Raman spectroscopy confirmed excellent nanotube alignment with mosaic FWHMs as low as 4°.

Abstract

This Letter describes the production of single-wall carbon nanotube (SWNT) – polymer composites with enhanced mechanical and electrical properties and exceptional nanotube alignment. A combination of solvent casting and melt mixing was used to disperse SWNT materials in poly(methyl methacrylate) (PMMA). Composite films showed higher conductivity along the flow direction than perpendicular to it. Composite fibers were melt spun to achieve draw ratios between 20 and 3600. The elastic modulus and yield strength of SWNT–PMMA composite fibers increased with nanotube loading and draw ratio. Polarized resonant Raman spectroscopy indicates that the nanotubes in the fibers are well aligned, with mosaic distribution FWHMs as small as 4°.