Novel continuous poly(vinylidene fluoride) nanofibers

Poly(vinylidene fluoride) (PVDF) is well known for its ferroelectric and piezoelectric properties. Currently, this polymer is used in applications in the form of films. PVDF fibers are expected to open up exciting new opportunities such as design and use of active textiles and composites. It is well-known that synthetic fiber properties improve substantially with the decrease of their diameter. However, conventional mechanical fiber spinning processes usually produce fibers with diameters in the range from tens to hundreds of microns. In this work, ultrafine, submicron-diameter continuous PVDF nanofibers were fabricated by electrospinning method. The method consists of spinning polymer solutions in high electric fields. Effects of process parameters on nanofiber diameter and morphology were studied. XRD and FTIR analyses of PVDF nanofibers were performed. The latter indicated that the initial a phase of the raw material was converted to beta phase PVDF during electrospinning. As beta phase is primarily responsible for the piezo- and ferroelectric properties of PVDF, the latter result is very encouraging. The demonstrated novel continuous PVDF nanofibers can be used in nanostructured active textiles and composites and can lead to unusual new designs for actuators and sensors.