Electric Field‐induced Orientation of Carbon Nanomaterials in Dispersions

Abstract

Carbon nanomaterials (CNMs) exhibit excellent performance and potential application value in optical, electric, magnetic and thermal owing to their unique low dimensional structures, high specific surface areas and excellent electrical conductivities, however, the random orientation of CNMs in polymer dispersions negatively affects their optimal performances. Herein, the orientation of CNMs induced by an electric field in dispersions was investigated. The arrangement of carbon black, carbon nanotubes and graphite nanoplatelets in solvents under an electric field was characterized using a stereoscopic microscope. The effects of solvent type, nanomaterial concentration and electric field conditions on the orientation of the CNMs were systematically investigated. The results showed that the CNMs generally exhibited good electric field‐induced orientations in solvents with a low relative dielectric constant. The orientation structure resulting from using an appropriate CNMs concentration was relatively uniform and continuous. In particular, a more regular orientation structure was achieved upon applying an electric field (100 V/mm; 1000 Hz) for 30 s. Interestingly, well‐oriented CNMs in a solvent can also orient in polymer dispersions that are soluble in such a solvent. This extension of the orientation of CNMs from solvents to polymer dispersion systems provides a novel idea for preparing high‐performance composites.