Flame-retardant, Antimicrobial, and UV-protective Lignin-based Multilayer Nanocoating
Creating multifunctional textiles using chemicals from renewable sources is challenging. In an effort to develop a sustainable and efficient multifunctional cotton treatment, a lignin-based multilayer nanocoating comprising magnesium lignosulfonate, chitosan, and monoammonium phosphate (MAP) was deposited using layer-by-layer assembly. A five bilayer coating adds 15.5 wt % to cotton and imparts fire extinguishing behavior and excellent UV and antimicrobial protection to the fabric. Just a two bilayer coating imparts sufficient self-extinguishing behavior to pass the standard vertical flame test. The combined influence of lignin as a char-forming and UV-protective macromolecule, chitosan as a char-forming biopolymer, and MAP acting as an antimicrobial agent (and a blowing agent and an acid source in an intumescent flame retardant system) results in a very powerful multifunctional textile treatment with very few layers of deposition.
J. Petkovska, N. Mladenovic, D. Markovic, M. Radoicic, N. A. Vest, B. Palen, M. Radetic, J. C. Grunlan, I. Jordanov, ACS Applied Polymer Materials, 2022, 4, 4528.