Physicochemical and mechanical properties of polyvinylidene fluoride nanofiber membranes

Polyvinylidene fluoride (PVDF) is hydrophobic, piezoelectric, and has good chemical stability and high mechanical properties; therefore, it is often used to reinforce other composite materials for various applications. However, the characteristics of pure PVDF nanofibers have rarely been comprehensively explored. This study prepared pure PVDF nanofiber membranes using electrospinning and investigated their physicochemical and mechanical properties. Scanning electron microscopy revealed that the PVDF nanofiber surfaces were white, homogeneous, flat, bead-free, and smooth, and that the nanofiber diameters were 230–855 nm. Fourier-transform infrared analyses showed that the β phase was dominant in all the nanofibers. The spectra showed that the α, β, and γ phases were present in PVDF1 and PVDF2, whereas PVDF3 and PVDF4 were dominated by the β and γ phases. The PVDF nanofiber samples had a semi-crystalline structure with crystallinity values of 58.45–52.67%. The tensile strength of the PVDF nanofibers increased from 3.61 to 6.00 MPa with an increasing PVDF concentration. The application of a high voltage during the electrospinning process did not damage the chemical structure of the PVDF nanofibers. The PVDF nanofiber membranes produced in this study are potential candidates for application in wound healing, water filtration, and masks. Increasing concentrations of PVDF affect the physicochemical and mechanical properties of PVDF nanofibres, which improve the morphology and tensile strength of PVDF nanofiber membranes. Moreover, an increasing concentration of PVDF influences the nanofiber crystallization process, with the typical β phase being the dominant.