The Use of Copper Ions and Tannic Acid to Enhance the UV Protection of Cotton Fabrics

An ultraviolet (UV)-protective cotton fabric has been developed by combining tannic acid and copper ions (TA-Cu) on cotton fabrics. The structure and properties of TA-Cu and cotton fabrics finished with TA-Cu were characterized by Fourier-transform infrared spectroscopy, ultraviolet-visible spectroscopy, scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The UV resistance and laundering durability of modified cotton fabrics were measured. The cotton fabric finished with tannic acid showed a maximum UV-protection factor value of 44.5, which was further improved by chelation with copper ions. The cotton fabric finished by the TA-Cu exhibits a UV-protection factor value of up to 172.1 and a UV transmittance of less than 1.5% when the concentration of tannic acid and copper ions was 0.1 mmol/L. The as-prepared cotton fabrics retained their UV resistance after laundering. This study proposes an eco-friendly anti-UV treatment for cotton fabrics and a novel application for tannic acid and copper ions to imbue fabrics with UV protection.