Atomic force microscopy studies of LAPONITE® directed self-assembly of single-walled carbon nanotubes in electronic nanonetworks

Abstract

Many commercial applications of carbon nanotubes (CNTs) have not yet been realized owing to their limited water processability that leads to poor electrical performance. We report the syntheses of oxidized single-walled carbon nanotubes (SWCNTs) with improved percolating network connectivity and conductivity in thin films processed from aqueous colloids mixed with dispersing agents including LAPONITE® nanoparticles and surfactants. The influences of clay loading and acid functionalization on surface morphology and the self-assembly of interconnected networks in SWCNT films were studied. Conductive atomic force microscopy (c-AFM) analyses indicated that the most favorable nanonetwork for charge conduction was achieved at a low loading of LAPONITE® nanoparticles. In addition, hydrazine reduction treatments after acid functionalization led to augmented electrical conductivities in the CNT films regardless of the extent of clay loading. These studies provide important insight on tuning the heterointerfaces that control CNT self-assembly and polydispersity and may prove insightful to realize percolating networks for green energy applications.