Preparation of Ag NPs and Its Multifunctional Finishing for Cotton Fabric

To explore the combination of silver nanoparticles (Ag NPs) prepared in a green manner with cotton fabrics and the washing durability of the fabric after the combination. In this paper, the natural material, honeysuckle extract, was used as a reducing agent to prepare the Ag NPs' solution. The structure and size of Ag NPs were analyzed using ultraviolet-visible spectrophotometry (UV-vis), transmission electron microscopy (TEM), dynamic light scattering (DLS), X-ray powder diffraction (XRD), and Fourier transform infrared (FT-IR) spectroscopy characterization. The results showed that Ag⁺ was successfully reduced to Ag⁰ by the honeysuckle extract, the particle size was about 10.59 nm, and the potential was -42.9 mV, so it had strong electrostatic repulsion and good stability. Meanwhile, it was found that the synthesized Ag NPs were well coated by the honeysuckle extract, so they would not aggregate. Then, the cotton fabric was finished with Ag NPs' solution by the dipping method using a complex of polymaleic acid (PMA) and citric acid (CA) as a cross-linking agent to fix Ag NPs on the cotton fabric. The structures of cotton fabrics before and after finishing were characterized using FT-IR, scanning electron microscopy (SEM), XRD, X-ray photoelectron spectroscopy (XPS), and thermogravimetric (TG) analysis, and the multifunctional properties of the finished cotton fabrics were explored by measuring the antibacterial rate, the wrinkle recovery angle (WRA), and the UV protection factor (UPF) value. The results show that Ag NPs were successfully loaded onto cotton fabric, and the PMA + CA compound was successfully cross-linked to the fabric. The cross-linked Ag NPs' cotton fiber was rougher than that before cross-linking, and its TG stability improved. The PMA + CA compound fixed Ag NPs on the cotton fabric through chemical bonds, so it still had a 99% antibacterial effect against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) after 50 washings. Compared with unfinished cotton fabric, the UPF value and WRA of the cross-linked Ag NPs cotton increased by 34.09 and 98°, respectively, and its color did not change much.