Fine powders from dyed waste wool as odor adsorbent and coloration pigment

Herein, waste dyed wool was transferred into wool powder (WP) using a mechanical pulverization process. This powder benefits from the rich exposed functional groups and porous structures, which endow WP with capacities to adsorb odor molecules. WP milled for 6 h exhibited improved properties including homogeneous surfaces, small mean particle size (3.63 μm) and increased surface area, contributing to its highest odor ammonia adsorption capacity (2.65 mg g⁻¹) and removal rate (91%) among all tested samples. Loading with WP endows cotton fabrics (CF) with greatly improved deodorizing properties and vivid color. WP-coated CF displayed improved ammonia removal properties compared to pristine CF, achieving 65.71% adsorption rate. The K/S value of WP-coated CF reached 1.844 at o.w.f.% of 15. Coated fabrics also showed stable color fastness to washing. This study paves the way for using powders from waste as both odor adsorbent and coloring pigment for fabric functionalization.