Nanofibrillar Poly(vinylidene fluoride): Preparation and Functional Properties

Poly(vinylidene fluoride) (PVDF) forming β-phase polymorphic modification shows strong ferro- and piezoelectric property as a crucial electroactive polymer and can be obtained by subjecting the highly oriented PVDF fibers to strong electric fields. Two different nanofibrillar materials: PVDF nanofibrillar single polymer composite (NF-SPC) and electrospun PVDF nanofibers were produced for this research. PVDF NF-SPC was prepared by hot compaction of PVDF nanofibrils separated from a PVDF nanofibrillar composite and a high electric field was used to drive out electrospun PVDF fibrils. Polymorphic change and morphology of constituents of the two samples were investigated and measurement of ferro- and piezoelectric behavior was performed after poling treatment. As a result, highly oriented nanofibrils were observed from the two samples and the formation of the β-phase was clearly detected compared to undrawn isotropic PVDF. Higher remnant polarization values and piezoelectric resonance behavior were detected from the samples, in which the β-phase polymorphic modification dominates.