Sustainable Dyeing and Functionalization of Wool Fabrics Using Chestnut Shell Extract

Chestnut shells, which are a byproduct of agricultural and food processing industries, contain various compounds such as polyphenols and flavonoids that are beneficial to human health. Furthermore, the brownish pigment in chestnut shells is often used to dye textiles. This study explores the feasibility of using chestnut shells—a biowaste—to dye wool fabric using a sustainable textile dyeing process that can impart beneficially functional properties to the dyed fabric. Chestnut shell flakes were boiled in water to prepare an aqueous solution, which was then filtered, centrifuged, concentrated, and dried to obtain a chestnut shell extract. The powdered extract was then dissolved in distilled water at a concentration of 7 wt% and applied to wool fabrics using a laboratory infrared dyeing machine. The dyed wool fabrics were analyzed using spectrophotometry, scanning electron microscopy, and Fourier-transform infrared spectroscopy. The functional properties of the dyed fabrics, namely the antibacterial, antioxidant, and deodorant properties, were analyzed as well. The wool fabrics turned a brownish hue when dyed using the chestnut shell extract, and the dyeing temperature had a stronger influence on the color strength compared with the dyeing duration. The dyed wool fabrics also exhibited significant antibacterial, antioxidant, and deodorant properties after dyeing under optimal conditions of 100 °C for ≥120 min.