Eco-Friendly Dyeing of Wool Fabric by a Natural Dye Extracted from Dates Kernels

Abstract

This study investigates the sustainable valorization of date kernels, an abundant agricultural by-product, for eco-friendly wool dyeing applications. Date kernels were cleaned, dried, finely ground, and extracted using a water/acetone system to obtain a natural dye, which was subsequently characterized by Fourier Transform Infrared Spectroscopy (FTIR) and zeta potential analysis. The dye was applied to wool fabrics followed by post-mordanting with five metal salts and silver (Ag) and titanium dioxide (TiO₂) nanoparticles. The dyed fabrics were evaluated in terms of color strength (K/S values), CIELabch color coordinates, fastness properties (light, washing, rubbing, and perspiration), ultraviolet protection factor (UPF), and antibacterial performance. Scanning Electron Microscopy (SEM) was employed to assess surface morphology. The results revealed bright yellow shades with high color strength values, dependent on mordant type and dye concentration. Light fastness ratings ranged from medium–good to very good, washing fastness was excellent, and rubbing and perspiration fastness values ranged from very good to excellent. In addition, the dyed fabrics exhibited notable antibacterial activity against Escherichia coli and Staphylococcus aureus and presented UPF values ranging from excellent to insufficient. These findings demonstrate the feasibility of using date kernel-based dyes as a sustainable, high-value alternative for eco-friendly wool coloration.