Robust, conducting, and transparent polymer composites using surface-modified and individualized double-walled carbon nanotubes

A demonstration on the use of double-walled carbon nanotubes (DWNTs) with two coaxial concentric tubes, as reinforcing filler in polymer matrix, is presented. It was observed during the demonstration that chemical moieties on the sidewalls of the DWNTs can affect the individualized species of DWNTs in dimethylformamide (DMF). DWNTs dispersed in polyimide with chemical modification and an in situ polymerization process can improve mechanical, thermal, and electrical properties of polyimide composites. Chemical moieties like carboxylic, benzylisocyanate, and phenylisocyanate groups were introduced on the sidewall of DWNTs to improve dispersability of the DWNTs and activate the surface sites. The study also observed that individually reinforced DWNTs can make polyimide more stronger and ductile without any degradation of transparency.