Fabrication of transparent conductive carbon nanotubes/polyurethane-urea composite films by solvent evaporation-induced self-assembly (EISA)

Transparent and conductive carbon nanotubes (CNTs)/polyurethane-urea (PUU) composite films were prepared by solvent evaporation-induced self-assembly (EISA). Pristine CNTs were treated with acids (H2SO4/HNO3 = 3:1, v:v), acylated with thionyl chloride, and purified after filtration. These acylated CNTs (0.05 wt.% in dimethylformamide, DMF) were deposited onto the 3-aminopropyl triethoxysilane (APTES)modified glass substrate by DMF EISA at 100 degrees C with the withdrawal rate of 3 cm/h. The CNT layers of 200-400 nm thicknesses were transferred to the PUU films by solution casting or resin transfer molding (RTM) at ambient temperature. Optical transmittances of the composite films were 60-75% at 550 nm wavelength and their sheet resistances were 5.2 x 10 degrees-2.4 x 10(3) k Omega/square, and which varied significantly with type of CNTs and the transferring methods of CNT layers. (C) 2008 Elsevier Ltd. All rights reserved.