Patterning of Polyimide/Single-Walled Carbon Nanotube Composite and Its Electrical Properties

Abstract

We have investigated the electrical properties of solution-processed polyimide/carboxylic acid functionalized single-walled carbon nanotube (SWCNT-COOH) composites. The electrical conductivity of the polyimide/SWCNT-COOH composite markedly increased with SWCNT-COOH loading significantly lower than 1 wt %. The conductivity of the polyimide/SWCNT-COOH composite further increased with electric-field treatment of half-dried polyimide precursor films. The polyimide/SWCNT-COOH composite was also patterned by low-temperature thermal nanoimprint lithography of uncured polyamic acid/SWCNT-COOH films by a silicone elastomer. The current was observed only in the direction parallel to the line patterns and could not flow across the lines, thereby indicating the presence of negligibly thin residual layers. The field-emission (FE) properties of the polyimide/SWCNT-COOH composite deposited by ac-coupled electrophoresis were also investigated and excellent FE properties were obtained, especially for deposition on an indium tin oxide (ITO) electrode that is selectively coated by micropatterned polymer banks.