Effect of spray process conditions on uniformity of carbon nanotube thin films.

Industrial use of carbon nanotube (CNT) films is increasing rapidly due to their good physical properties and high economic feasibility. Spray coating process is one of feasible approaches for large area CNT films. Uniform spray coating is an important issue in applications requiring large area conductive films. In the present work, we developed a numerical model for the prediction of CNT deposition thickness distribution in the spray process and validated the numerical work by using experimental data obtained in this study. We investigated the deposition thickness distributions according to various process parameters by using the numerical model. We found that the pitch of the nozzle path is a key parameter affecting the deposition thickness uniformity and that there is optimal pitch value for unfirom and productive coating. We also discussed future research direction for improved numerical simulation tool. Since the present numerical model is also applicable to simulation of spray process on curvy substrate, the numerical model could be an imporatnt step toward a powerful simulation tool for design and optimization of the nanomaterial spray process.