Silver-clay nanohybrid as a coating for improvement of the antibacterial properties of paper

This comparative study was carried out to investigate the effect of nanosilver, silver-clay nanohybrid, and silver-milled clay nanohybrid coatings on the antibacterial characteristics of paper. Nanosilver (25 ppm) was used as a singleand double-layer coating. The results demonstrated that treatment with pure nanosilver was more efficient in the reduction of microbial growth. Also, milling of clay enabled better maintenance of silver nanoparticles, and led to a greater decrease in bacterial growth than in the case of the original silver-clay nanohybrid. Evaluation of the sustainability of antibacterial characteristics confirmed that, although pure nanosilver treatment achieved better performance in the first 15 minutes than nanohybrid samples, the performance of the nanohybrids improved with the passing of time. As expected, the treatments decreased the brightness of paper, while the opacity increased significantly; pure nanosilver treatment led to lower brightness than the others, and the opacity was higher in the case of the silver-clay nanohybrid than with the other treatments