Effect of graphene oxide nanoparticle coatings on the strength of packaging paper and its barrier and antibacterial properties

Abstract

The aim of this study was to assess the performance of graphene oxide nanoparticles in paper coating formulations in order to improve the antibacterial, physical and mechanical properties of paperboard. The paper was coated with graphene oxide nanoparticles at concentrations of 100 and 200 ppm together with 5% cationic starch (dry weight) as a retention aid and for better coverage and more homogeneous positioning of nanographene oxide particles on the surface of the paper. The paper surface coated with nanographene oxide particles and starch was characterised using ATR-FTIR and SEM. The antibacterial assay was performed according to the Turbidity Method. For the antibacterial tests of paper sheets, Escherichia coli and Staphylococcus aureus were used as Gram-negative and Gram-positive bacteria respectively. The results showed that UV adsorption was reduced, with the largest reduction obtained when using nanographene oxide particles at 200 ppm. Turbidity in the samples including S. aureus was also lower. The growth rates of S. aureus bacterium in the control and the paper specimens coated with 200 ppm nanographene oxide were 89% and 24%, respectively. The density and thickness of the paper sheets increased in the paper coated with cationic starch and nanoparticles in comparison with uncoated paper. The nanoparticles had no significant effect on the thickness of coated papers. The addition of nanographene oxide particles improved the resistance to air and barrier properties of paper sheets. The burst and tear indexes increased for the paper coated with starch and nanographene oxide particles.