Characterization of an electroactive polymer (PVDF-TrFE) film-type sensor for health monitoring of composite structures

Abstract

Poly(vinylidene fluoride) (PVDF) is one of the most promising electroactive polymers with numerous potential applications in many industrial fields. Three different conventional treatments (annealing and cooling, electrical poling, and pressing) were conducted to enhance the beta-phase of the P(VDF-TrFE) films. Moreover, sequential treatments involving each process were conducted to elucidate the effect of the sequence of treatments on the beta-phase transformation in the P(VDF-TrFE). By primarily using X-ray diffraction, microscopic analysis was conducted to investigate the effect of such treatments on the piezoelectric properties of the P(VDF-TrFE) films. It could be determined from the results that the annealing and cooling, electrical poling, and pressing treatments were all effective and the sequential treatments were also effective in enhancing the crystallinity of the beta-phase of the P(VDF-TrFE). The maximum beta-phase fraction (66.33%) was obtained from the sequential treatment of "annealing and cooling-pressing-electrical poling" while the control group only exhibited a beta-phase fraction of 45.29%. (C) 2015 Elsevier Ltd. All rights reserved.