Mechanism of Acid Dyes Adsorption on Silk Yarn Modified with β-Cyclodextrin Nanostructure

This research modified the degummed silk yarn with β-cyclodextrin (β-CD) using Succinic acid (SUA). Then, the modified silk yarn was dyed with three different acid dyes through usual (with acid) and unusual (without acid) methods. The surface modification and inclusion complex were characterized by well-known analyses such as Fourier transform infrared (FTIR), attenuated total reflectance-FTIR (ATR-FTIR), Scanning electron microscope (SEM), X-ray diffraction (XRD), and UV-visible. Results show that the presence of the β-CD has markedly enhanced the dye adsorption, and also, the acid has an effective role in the dye adsorption mechanism. The improvement of dye adsorption can be related to chemical (H-bonding and ionic) and physical (inclusion complex and encapsulation into tridimensional polymeric network) interactions. In addition, the β-CD had no negative effect on the color fastness (wash, light, and rubber) of the modified silk samples, so the color fastness of most samples remained unchanged or did not show a noticeable decrease.