title: Influence of ferrite nanoparticle type and content on the crystallization kinetics and electroactive phase nucleation of poly(vinylidene fluoride).
abstract: This work reports on the nucleation of the β-phase of poly(vinylidene fluoride) (PVDF) by incorporating CoFe(2)O(4) and NiFe(2)O(4) nanoparticles, leading in this way to the preparation of magnetoelectric composites. The fraction of filler nanoparticles needed to produce the same β- to α-phase ratio in crystallized PVDF is 1 order of magnitude lower in the cobalt ferrite nanoparticles. The interaction between nanoparticles and PVDF chains induce the all-trans conformation in PVDF segments, and this structure then propagates in crystal growth. The nucleation kinetics is enhanced by the presence of nanoparticles, as corroborated by the increasing number of spherulites with increasing nanoparticle content and by the variations of the Avrami's exponent. Further, the decrease of the crystalline fraction of PVDF with increasing nanoparticle content indicates that an important fraction of polymer chains are confined in interphases with the filler particle.
authors.affiliation: Centro/Departamento de Física, Universidade do Minho, Campus de Gualtar, 4710-058 Braga, Portugal.
authors.forename: Vitor
authors.initials: V
authors.lastname: Sencadas
authors.forename: Pedro
authors.initials: P
authors.lastname: Martins
authors.forename: Alexandre
authors.initials: A
authors.lastname: Pitães
authors.forename: Maria
authors.initials: M
authors.lastname: Benelmekki
authors.forename: José Luis
authors.initials: JL
authors.lastname: Gómez Ribelles
authors.forename: Senentxu
authors.initials: S
authors.lastname: Lanceros-Mendez
mesh_terms: D003460:Crystallization; D004560:Electricity; D005290:Ferric Compounds / Q000737:chemistry*; D007700:Kinetics; D008280:Magnetics; D053758:Nanoparticles / Q000737:chemistry*; D011145:Polyvinyls / Q000737:chemistry*; D012996:Solutions; D005465:Fluorocarbon Polymers
chemical_list: D005290:Ferric Compounds; D011145:Polyvinyls; D012996:Solutions; C001215:ferrite; C024865:polyvinylidene fluoride; D005465:Fluorocarbon Polymers