Silk fabrics modified with Si ₄ N ₃ @Ag nanoparticles for photothermal conversion and bacteriostatic properties

Silk has weak bacteriostatic and ultraviolet (UV) resistance properties. To improve this property, in this work, Si ₄ N ₃ @Ag composite nanomaterials were synthesized. Subsequently, they were used to modify the surface of silk fabrics with the assistance of silane coupling agent KH792; this modification treatment not only enhanced the bacteriostatic and UV-resistant properties of the silk fabrics, but also endowed them with unique photothermal properties. Under near-infrared irradiation, at a wavelength of 808 nm and an irradiation power of 0.134 W/cm ² , the temperature of the Si ₄ N ₃ @Ag silk fabric rapidly increased from a room temperature of 29.9°C to 61.1°C in only 45 s. Moreover, its photothermal efficiency remained essentially unchanged after a number of cycles. The results of antibacterial experiments further showed that the fabric had significant antibacterial effects against common bacteria, such as Escherichia coli and Staphylococcus aureus , and that its antibacterial performance remained significant even after a number of washes. In addition, thermogravimetric analysis showed that the introduction of Si ₄ N ₃ @Ag nanoparticles helped to improve the thermal stability of the silk fabric. Meanwhile, UV transmittance results showed that the Si ₄ N ₃ @Ag silk fabrics possessed good UV resistance. Finally, biocompatibility experiments confirmed that the Si ₄ N ₃ @Ag silk fabric has good biocompatibility, ensuring its safety and reliability in applications. In this work, a silk fabric with several functionalities was developed: it is excellent in photothermal conversion, antimicrobial, thermal stability, and UV resistance, and has good biocompatibility, and is expected to be widely used in many fields.