Wool functionalization through AgNPs: coloration, antibacterial and wastewater treatment

Herein, an approach was carried out toward in situ synthesis of chitosan-mediated silver (Ag) nanoparticles (AgNPs) on merino wool fabrics (MWFs) and its utilization as colored textile, antibacterial material and removable substrate after toxic dye reduction. The investigation on the as-produced products (AgNPs@MWFs) indicates that AgNPs were successfully assembled on the MWF surface through efficient interaction between the wool and chitosan terminals with nanoparticles. The AgNPs@MWFs revealed three primary colors (red, yellow and blue) with a brilliant shade due to the localized surface plasmon resonance properties of metal nanoparticles. The colorfastness and color strength (K/S) values were found to be as significant as those of traditional dyes. The tensile properties of the MWFs, such as strength and elongation at break, were measured before and after in situ synthesis of AgNPs and were found improved compared with those of the control samples. The antibacterial performance was also noticed to be excellent with ∼99% bacterial reduction after five consecutive standard washes. Afterward, AgNPs@MWFs coupled with sodium borohydride (NaBH₄) were used for azo-containing wastewater treatment. Higher than 90% azo-dye degradation by 30 min was found, which was six times faster than that of the control sample.