Direct fabrication of a 3D-shape film of polyvinylidene fluoride (PVDF) in the piezoelectric β-phase for sensor and actuator applications. (February 2018)

• Record Type: Journal Article
• Authors: Lopes, A.C.; Gutiérrez, J.; Barandiarán, J.M.
• Is Part Of: European polymer journal. Volume 99(2018)
• Page Start: 111
• Page End: 116
• Publication Date: 2018-02
• Subjects: Poly(vinylidene fluoride) -- PVDF -- Ionic liquid -- Piezoelectricity -- 3D -- Three dimentional -- Electroactive polymers; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; Polymerization; Polymers; Periodicals; Electronic journals; 547.705
• DOI: 10.1016/j.eurpolymj.2017.12.009
• Languages: English
• ISSNs: 0014-3057

Abstract

Graphical abstract: Highlights: A new method to fabricate pure β-PVDF by melting was investigated. PVDF β-phase crystallization is promoted by the inclusion of ionic liquids. IL can be removed by immersion of the film in hot-water. The pure β-PVDF produced by this new method present a d33 coefficient of −27 pC N −1 . For the first time, a 3D shape film of pure β-PVDF is produced. Abstract: Until now, getting non-porous pure PVDF in the piezoelectric β-phase involved the application of stresses that limit the production of piezoelectric films into a flat form. In this work we present a new method to obtain, directly from the melt, pure β-PVDF which also allows the production of films with a 3D shape. A hydrophilic ionic liquid (IL), C2 mim BF4, is used to totally induce the direct crystallization of PVDF in the piezoelectric β-phase during the melt. Afterwards, this IL is completely removed by washing the film in water at 70 °C. The process results in the production of a non-porous pure PVDF film, totally crystallized in the β-phase. Finally and for the first time, the replication of a 3D shape given by a glass form could be demonstrated by using this polymer.