Electrospun carbon nanodot-doped PVDF nanofibers with enhanced crystallinity, hydrophobicity and UV resistance

PVDF is known to be synthesized into nanofibers for various applications, including wastewater treatment through oil-water separation, adsorption, and filtration. However, long-term stability and fouling remain significant shortcomings. In this study, low-cost, steam-activated date palm fronds carbon nanodots (DPF CNDs) derived from natural sources were incorporated into polyvinylidene fluoride (PVDF) nanofiber mats at varying concentrations ranging from 0 to 5 wt%. We investigated the impact of CNDs loading on surface morphology, wettability, crystalline structure, thermal stability, mechanical properties, and UV resistance. We found that α-phase crystallinity increased with increasing CND concentration; the membranes also exhibited thermal stability, with a slightly decreasing melting temperature. Additionally, a slight decrease in tensile strength was observed with increasing elongation at break, as measured by mechanical testing, indicating improved flexibility. Enhanced hydrophobicity was also observed, as evidenced by a higher contact angle that remained stable after UV exposure, thereby demonstrating improved UV resistance. Therefore, these CND-doped PVDF nanofibers demonstrated potential for antifouling applications, particularly in the adsorption of organic pollutants and oil-water separation.