Polyrhodanine Coated Cellulose Nanocrystals: A Sustainable Antimicrobial Agent

Abstract

This paper reports on a simple and green approach to fabricate cellulose nanocrystal@polyrhodanine (CNC@PR) core–sheath nanoparticles. Polymerization of rhodanine on the surface of negatively charged CNC was achieved using ferric chloride as the initiator and oxidant. The coating conditions were optimized by varying the ratio of CNC and monomer as well as the concentration of oxidant. Antimicrobial tests were performed using Escherichia coli (Gram negative) and Bacillus subtilis (Gram positive) as model bacteria and the minimum inhibitory concentrations were determined by plate colony counting methods. Rod-like CNC@PR nanoparticles exhibited promising antimicrobial properties, comparable to spherical nanocomposite particles. This may be attributed to the lower percolation threshold for rod-like nanoparticles resulting from the higher aspect ratio. By taking advantage of the nanosize effects, the core–sheath material can be a potential candidate for antimicrobial applications, such as food-packaging, antimicrobial additives and antimicrobial surfaces or coatings.