Evaluation of Washing Fastness on Chitosan‐Treated Cotton Fabrics

Wearing an antimicrobial garment is a priority to guarantee the safety of clothes in hospitals and elsewhere. The antibacterial treatment must be durable and stable overtime. This work studied the washing fastness of cotton fabrics functionalized with chitosan. Chitosan deposition was carried out using acetic acid to favor chitosan solubilization. Ten washing cycles with ionic and nonionic detergents were executed to evaluate the durability of the antimicrobial activity. The different properties were monitored after the 1st, the 3rd, and the 10th cycles using the untreated cotton sample as a reference. The physicochemical characterization of the washed fabrics was analyzed by microscopy, spectroscopy and contact angle. Additionally, the color changes in the CIELab Δ E of the samples were evaluated relative to plain cotton fabric. Furthermore, the mechanical properties were assessed, as well. The characterization highlighted the durability of the chitosan treatment on cotton fabrics, even after repeated laundering. The antibacterial tests demonstrated that the antibacterial properties were maintained above ~98% of bacterial reduction after washing with ionic and nonionic detergents. The samples washed with the nonionic solution at 50°C with 25 stainless steel balls showed the best antibacterial activity and tensile strength up to 10 washing cycles.