The impact of TiO₂ particle and porous structure on UV resistance application for wet-spinning PVDF fiber

The ultraviolet (UV) resistance refers to the ability of materials to block, absorb, or reflect UV rays. Traditional fiber modification and fabric post-treatment techniques for UV resistance enhancement mainly focus on increasing the UV absorption rate or scattering effect, but there is still significant room for improvement. In this work, we prepared two types of Poly(vinylidene fluoride) (PVDF) fibers through the wet-spinning process: PVDF fibers with a single porous structure and PVDF fibers with added titanium dioxide (TiO₂) particle (exhibiting high UV absorption) (PVDF/TiO₂ fibers). Through the former, we explored the influence of changes in the internal porous structure of the fibers on their UV resistance. And contrast the effects and possible mechanisms of these two fibers regarding UV Resistance. We employed characterization techniques such as SEM, XPS, XRD, and Ultraviolet-Visible-Near Infrared (UV-VIS-NIR) Spectrophotometer. The experimental results show that the average UV transmittance of the two types of fibers is remarkably low(<0.3%). Analysis indicates that they achieve excellent UV resistance via different mechanisms. The porous PVDF fibers possess excellent average UV reflectivity (>80%), while the PVDF/TiO₂ fibers show exceptional UV absorptivity (>82%). There are differences in the effects and applications of UV resistance based on the principles of reflection or absorption. Consequently, the two types of fibers can be applied in diverse scenarios. Moreover, given the large - scale production characteristics of wet - spinning, these fibers hold promising market prospects.