Effect of Drying Method and Pore Size on the In-Plane Electrical Properties of Multiwalled Carbon Nanotube films Deposited on Paper Substrates

R.L. Muhlbauer, R.A. Gerhardt
Georgia Institute of Technology, US

Keywords: carbon nanotubes, paper pore size, in-plane sheet resistance

Summary:

Carbon nanotube networks are often made by vacuum deposition on top of paper substrates. In this study we report on the properties of MWNT thin films deposited on paper substrates with different pore size (1 µm, 5 µm, 25 µm, and 40 µm). It is demonstrated that the in-plane electrical properties of four-layered MWNT films depend substantially on the pore size of the underlying paper substrate and the method that was used to dry the films. All films were deposited using the same solution of 1 mg/mL MWNTs dispersed in water with 10 mg/mL SDBS surfactant. Each layer was completely dried before the next layer was deposited. The films were dried using three different methods: vacuum filtration, drying in a 65°C oven, and drying in an oven on top of a heated substrate. Even though the chemistry of the films are all the same, the electrical and structural characteristics of the 4-layer films were found to vary from 6 kΩ/sq to 1GΩ/sq. This suggests that it is important to pay attention to the characteristics of the paper substrates used to deposit MWNT networks before they are transferred to the devices they will be used in.