Ag-lignin hybrid nanoparticles for high-performance solar absorption in photothermal antibacterial chitosan films

Jinrong Liu; Mika H Sipponen

doi:10.1016/j.isci.2023.108058

Ag-lignin hybrid nanoparticles for high-performance solar absorption in photothermal antibacterial chitosan films

iScience. 2023 Sep 25;26(10):108058. doi: 10.1016/j.isci.2023.108058. eCollection 2023 Oct 20.

Authors

Jinrong Liu¹, Mika H Sipponen^{1

2}

Affiliations

¹ Department of Materials and Environmental Chemistry, Stockholm University, 106 91 Stockholm, Sweden.
² Wallenberg Wood Science Center, Department of Materials and Environmental Chemistry, Stockholm University, 106 91 Stockholm, Sweden.

Abstract

There is an urgent need for antimicrobial films based on sustainable resources and production methods. In this study, we present a bio-based nanocomposite film composed of chitosan (∼60 wt %), lignin nanoparticles (LNPs, ∼40 wt %), a small amount of glutaraldehyde (1.5 wt %), and a trace level of silver nanoparticles (AgNPs, 0.072 wt %). The uniform dispersion with LNPs prevented aggregation of metallic silver, resulting in small (diameter 3.3 nm) AgNPs. The nanocomposite film absorbs 89% of radiation across the entire solar spectrum and exhibits a remarkable photothermally triggered antibacterial effect, which is further enhanced by the dark color of lignin. Under simulated solar light illumination, the nanocomposite films demonstrated a significant reduction in viable Escherichia coli count compared to control scenarios. The potential applications of these nanocomposites extend to sunlight-activated antimicrobial films and coatings, addressing the growing demand for sustainable and effective antimicrobial materials.

Keywords: Biomass; Biotechnology; Materials chemistry; Materials science.