Rational strategy for construction of multifunctional coatings for achieving high fire safety, antibacterial, UV protection and electrical conductivity functions of textile fabrics

Abstract

Sustainable and innovative multifunctional organic coatings were designed and developed for integrating effective flame retardancy, ultraviolet (UV) radiation protection, electrical conductivity and antibacterial functions to viscose textiles. The coatings-based nanocomposites were prepared from cellulose nanocrystal phosphate derived from waste cotton clothes, graphene sheets derived from mandarin shell, polyaniline nanofibers and polypyrrole (PPy) and elucidated using microscopic and spectroscopic tools. The nanomaterials-based coatings were first synthesized individually from their sustainable precursors and then utilized in nanocoatings fabrication. Variety of nanocoatings were developed from different combinations of nanofillers and mass ratios and then coated on viscose textile fabrics. The flammability, thermal stability, UV protection, electrical conductivity and antibacterial properties of the treated textile fabrics were studied and optimized. The flame retardancy properties of the developed textile fabrics were significantly improved achieving zero rate of burning compared to 193 mm/min for uncoated fabrics. This outstanding fire safety was ascribed to synergistic flame retardancy effect of coating layer based phosphorylated cellulose nanocrystals, graphene sheets and polyaniline nanofibers affording protective char barrier. The flame retardancy action was further elucidated using scanning electron microscopy (SEM) and Raman spectroscopy of protective char layer developed. Moreover, the coated fabrics affords excellent UV protection properties achieving ultraviolet protection factor (UPF) value of 90 compared to 2.7 for uncoated one. Additionally, new electrical conductivity feature was incorporated to the developed fabrics achieving reduction in electrical resistivity by 10,000 time affording conductive fabrics with convenient dissipation factor. Interestingly, the fabricated nanocoating integrates superior antibacterial properties against different bacteria strains Staphylococcus aureus (Gram-positive) and E-coli (Gram-negative) achieving clear antibacterial inhibition zone of 14.5 and 18.4 mm compared to zero mm inhibition for untreated one respectively. Furthermore, the influence of different nanocoatings on tensile strength properties of coated fabrics was studied and optimized.