Enhancing anti-pilling performance of wool knitted fabrics <i>via</i> synergistic treatment with dopamine and silk sericin: a sustainable approach

Pilling of wool knitted fabrics during wearing or washing has long been a persistent and challenging issue. Conventionally, most anti-pilling treatments are either environmentally unfriendly or cause substantial damage to the internal structure of wool. This study adopts dopamine cross-linking silk sericin to modify wool knitted fabrics. The effects of dopamine concentration, silk sericin concentration, and cross-linking reaction time on wool fiber scale parameters (fiber friction coefficient, crimp ratio, and crimp recovery rate), anti-pilling properties, air and moisture permeability, heat retention, and mechanical properties of wool knitted fabrics were investigated. Based on the synergistic effect between dopamine and silk sericin, the wool scales were effectively encapsulated, thereby reducing the directional friction effect. Optimal conditions were identified as 1 mg mL^-1 dopamine, 10 mg mL^-1 silk sericin, and 24 h cross-linking reaction time. Under these conditions, a directional frictional effect value of 0.66 was achieved along with a crimp ratio of 3.41%, a recovery rate of 3.08%, resulting in a pilling grade of 5. The modified wool knitted fabrics demonstrated enhanced heat retention ratio (57.3%) and moisture permeability (9.6%), with only a marginal decrease in air permeability. The cross-linking reaction between dopamine and silk sericin exhibited a low-energy molecular thermal excitation process with an activation energy of 30.8 kJ mol^-1.