Sustainable coatings based on core–shell pigments to enhance antibacterial and other beneficial paper properties

Abstract

Paper manufacturers are constantly looking for new methods to improve coated paper properties. Pigments are encountered in paper coatings to add new functions. For example, titanium dioxide (TiO2 ) and talc are considered among the best-known pigments used in paper coating and manufacturing due to their whiteness and other beneficial properties. Nevertheless, talc has a weak dispersion during which its particles agglomerate, and this disadvantage needs to be overcome before its application which means higher cost. Therefore, in this work, a core–shell technique is used to modify the talc surface and enhance its dispersion in order to promote its use in improving the properties of the paper. Core–shell pigments are composed of a thin shell of (nano- and micronized) titanium dioxide precipitated on talc particles. These prepared talc/TiO2 core–shell pigments were characterized using various techniques such as XRF, SEM, and TEM, and then they were incorporated in paper coatings to evaluate their effect on the different properties of the coated papers. The results showed that nano-talc/TiO2 with the obtained unique chemical and morphological structure has improved the physical, mechanical, and optical properties of the coated papers besides improving their antimicrobial activity, especially when compared to papers coated with micronized talc/TiO2.