Application of Inorganic Particles Modified with Polyvinylamine to Produce Antibacterial Paper

Antibacterial activity is one of the desired functionalities in paper and board grades, especially for packaging. This study designed a contact-active antibacterial surface using polyvinylamine (PVAm) bonded onto inorganic particles (kaolin), and investigated appropriate ways to utilize the treated inorganic particles as antibacterial carriers to produce antibacterial paper. Antibacterial inorganic particles were prepared by modifying the surface of kaolin through a polyelectrolytes multilayering (PEM) technique with a PVAm and polyacrylic acid system. The pH control during the PEM process affected the adsorption amount of PVAm and dispersion stability of PEM-treated kaolin. The PEM-treated kaolin was applied to prepared handsheets via two ways, internal addition or surface treatment. Only the surface-treated handsheets had a noticeably reduced bacteria ratio. Antibacterial activity was > 99.9% for Escherichia coli and > 99% for Listeria monocytogenes. The inactivation of bacteria with damaging membranes was confirmed by a dual staining method. The surface coverage of the PEM kaolin on the handsheets was an important factor for inactivation of the bacteria. As a result, the surface treatment of antibacterial inorganic particles was determined to be the proper strategy to produce antibacterial paper.