Influences of boron and nitrogen co-doped carbon dot based coating fabricated via layer-by-layer self-assembly on the UV protection and flame retardancy of cotton fabric

Boron and nitrogen co-doped carbon dots (BN-CDs) were synthesized using one-pot hydrothermal carbonization. The synthesized CDs were then combined with alginate and polyethyleneimine to create a multilayered coating on cotton fabric through layer-by-layer (LbL) self-assembly. The CD-containing coating emitted visible blue light under a 365 nm UV lamp. The UV protection, thermal stability, flame retardancy, and wash durability of the CD-treated cotton fabric were subsequently investigated. The ultraviolet protection factors of pure cotton fabric and cotton fabric treated with 12 bilayer CD-containing coating were 6.48 and 64.10, respectively. This indicated that the synthesized CD is an efficient UV absorber. In the TGA test, more char residue was observed at 700( degrees)C for CD coated cotton fabrics under a nitrogen atmosphere. After B, N co-doped CDs were enriched in the PEI/alginate multilayered coating, the peak heat release rate (PHRR) of cotton-CDs-12BL was reduced by 15%, and the TPHRR of cotton-CDs-12BL was improved by 26.4 C-degrees in the microscale combustion calorimeter test. These results indicate that B, N co-doped CDs which possess UV absorption and environmental friendliness, have potential application as a flame retardant on the surface of cotton fiber.