Investigating the performance of nano-TiO2 pigments incorporated within UV curable inkjet inks and coatings with reference to anti-pollution properties

Abstract

Air pollution is an increasing global issue driven by anthropogenic activities, including factory emissions and car exhausts. To tackle the air pollution phenomenon, incorporating nano titanium dioxide into inkjet inks has been considered due to the pigments potential role in reducing air pollution when using these inks to produce advertisement posters and billboard prints, which are ubiquitous on our air polluted city streets. A photocatalytic performance of 2% rutile nano-TiO2 inkjet prints produced by Nazdar Ltd (Stockport) was proven. This project involves the modification of an experiment, jointly devised by Colour Science Analytical at the University of Leeds and Nazdar Ltd (Stockport), to study the photocatalytic activity of inkjet inks that contain nano-TiO2 to degrade N2O. The experiment, however, had several potential issues that could have influenced the results, with gas leaking and significant temperature variation being the most important. Printed samples containing nano-TiO2 were exposed to UV light inside a closed system with relative humidity close to the UK average (76–88%). The photocatalytic capability was monitored through the increase in oxygen produced due to N2O breakdown. In both front-and back-lit positions, C.I. Pigment Yellow 150 outperformed other colours in the photocatalytic activity. Also, C.I. Pigment Yellow 150 outperformed C.I. Pigment Yellow 155 in photocatalytic performance when ink without nano-TiO2 was used in prints. C.I. Pigment Yellow 150 may have anti-pollution properties in the visible light region. However, additional investigation is necessary to ensure that the findings are reproducible, as this project involved an extensive number of samples on a range of substrates and varying colour strengths.