Surface Modification and Antibacterial Functionalization of Polyester Fabrics Using Deep Eutectic Solvent and Its Composite Solution

As an environmentally friendly solvent, deep eutectic solvent has become a research hotspot for fiber modification in recent years. In this paper, surface modification and functionalization of polyester fabrics (PET) were treated by the deep eutectic solvent of choline chloride/oxalic acid (ChCl/OA) and chitosan-dissolved ChCl/OA (ChCl/OA-CTS). The surface morphology, chemical structure, dimensional stability, mechanical properties, and antibacterial properties of PET before and after treatment were compared, and the results showed that PET fiber swelling occurred by ChCl/OA treatment, and fiber fineness increased by 15.92%. Scanning electron microscope (SEM) indicated that the surface roughness of the fiber increased and the surface etching occurred after washing and drying. Meanwhile, the adjacent fibers were “welded” to each other, resulting in increased friction between the fibers and improved stability of the fabric size. Fourier transform infrared (FTIR), energy dispersive spectrometers (EDS), and X-ray photoelectron spectroscopy (XPS) analysis showed that the chitosan was loaded on the surface of PET fiber after ChCl/OA-CTS treatment, the hydrophilicity of PET fiber was improved, and the inhibition rate of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was 92.04% and 92.16%, respectively. In conclusion, the PET was physically etched and reproduced, and the chitosan can be embedded in the fiber with the swelling of the fiber.