Thin Film Deposition of Nanoparticle Dispersions via Precision Inkjet Nano-Printing

This project deploys a Fujifilm Dimatix Materials Printer to print thin films of various nanoparticle dispersions such as titanium dioxide and organic thermochromic dyes. Immobilization of Titanium dioxide nanocoating will facilitate as the photocatalyst for breaking down the organic azo-dyes and polyfluoroalkyl compounds in wastewater. To successfully print a multi-layer coating on to the substrate, the size of the nanoparticle aggregations in the dispersion must be controlled using rotor-stator homogenization and subsequently with ultrasonic homogenization. The particle size is measured using dynamic light scattering, and the light absorption characteristics of the ink are measured using UV-Vis spectroscopy. The inkjet nano-printer enables precise control over the thickness of the thin films while allowing for a wide range of substrates to be used. The technology also allows for complex patterns, with resolutions of up to 30 microns, depending on the ink used. To analyze the thin films, the thickness is measured using an ellipsometer. In our preliminary research, we have optimized the homogenization processes to control the dispersed particle with size ranges below 200 nm for uniform coating and to avoid the nozzle clogging issues. Once the successful thin coating is validated, these immobilized films will be subjected to solar-photocatalysis experiment for wastewater treatment.