Dual functionalisation of polyurethane foam for unprecedented flame retardancy and antibacterial properties using layer-by-layer assembly of MXene chitosan with antibacterial metal particles.

Antibacterial surfaces in healthcare settings are an important tool for combating the increasing threat of antibacterial drug resistance, which the global Covid-19 pandemic has further exacerbated. Herein, we report a new method to achieve dual antibacterial and flame retardant functionalities in flexible polyurethane foam (PUF) by synthesising a multifunctional coating using a layer-by-layer assembly technique. The coating consists of Ti 3 C 2 nanosheets and chitosan as the flame retardant and metal particles (copper or silver) for the antibacterial property. Results show that the multilayer Ti 3 C 2 /CH/Ag coating possesses excellent antibacterial performance with reductions of 99.97% in gram-negative bacteria (P. aeruginosa) and 88.9% in gram-positive bacteria (S. aureus) compared with the unmodified counterpart. Compared with the pristine PUF, the multifunctional coating yielded 66.3% reductions in the PHRR, and demonstrated outstanding smoke suppression performance with a PSPR reduction of 51.6% and a TSR decline of 65.5%. Moreover, Raman spectroscopy revealed an increased graphitisation level in the residual char of the coated foam, indicating the coating's remarkable charring performance. This exceptional multifunctional performance endows the coating technology with a great potential for eradicating the fire risks of antibacterial surfaces in healthcare settings and providing furniture, interior walls and building panels with antibacterial properties. [Display omitted] • Ti 3 C 2 /chitosan and antimicrobial particles coated PUF is prepared via LbL assembly. • Dual functional PUF manifests excellent flame retardancy with 66.4% PHRR reduction. • Antimicrobial coating of silver ions decreases 99.97% of gram-negative bacteria. • Ti 3 C 2 and antimicrobial coatings synergistically enhance PUF charring performance. • A dual functional flame-retardant anti-microbial soft-furnishing foam is achieved. [ABSTRACT FROM AUTHOR]