A novel biofilm based on lignocellulosic compounds and chitosan modified with silver nanoparticles with multifunctional properties: Synthesis and characterization

Abstract

Lignocellulosic biomass has been acknowledged for potential use to produce chemicals and biomaterials. Lignin is the second most abundant natural polymer, making up to 10–25 % of lignocellulosic biomass. It would be favorable to find agents that could have antioxidant and antibacterial activities combined in one material. The discovery of natural compounds that can show a dual-target activity considerably increased in the last years, reflecting the growing confidence that this new approach could lead to better applications. This research aims to fabricate a novel biofilm of extracted natural lignin from bagasse and chitosan displaying significant properties such as antioxidant and antibacterial activities. Here, lignin was derived from bagasse wastes for the potential use in preparing a chitosan/lignin biofilm with different lignin and chitosan contents and then the prepared biofilm was modified with silver nanoparticles for enhancing multifunctional properties. Furthermore, SEM, TEM, FT-IR, and TGA analyses, investigation of antibacterial and antioxidant properties, solubility, swelling, and tensile strength tests of the samples were performed. The results showed with higher levels of lignin in the biofilm, hydrogel flexibility and swelling property increases but the tensile strength reduces. The results showed that chitosan/lignin has a high antibacterial activity against gram-positive and gram-negative bacteria. Also, the antioxidant activity of samples containing lignin was higher than samples without lignin. Besides, silver nanoparticle improves the solubility and antibacterial characteristics of the biofilm.