Publicação

Nanoparticle dispersion and electroactive phase content in PVDF/ Ni0.5Zn0.5Fe2O4 nanocomposites for magnetoelectric applications

Ver documento

Detalhes bibliográficos
Resumo:Ni0.5Zn0.5Fe2O4 ferrite/polyvinylidene fluoride composite films were prepared by a solution method and melt processing. As nanoparticle dispersion and polymer electroactive phase content are some of the key factors for improving magnetoelectric coupling in the composites, the dispersion of ferrite nanoparticles in the polymeric matrix was studied by preparing samples by two alternative dispersion routes: ultrasound and citric acid nanoparticle surfactation. The nucleation of the electroactive β-phase of the polymer was observed in composites produced by nanoparticle dispersion by ultrasound. This fact avoids the need of stretching composites at elevated temperature in order to obtain the electroactive phase and obtain magnetoelectric composites. By this method, nevertheless, large nanoparticle agglomerates are obtained. Nanoparticle dispersion is largely improved by citric acid surfactation of the nanoparticles. On the other hand, the β-phase of the polymer is not nucleated due to the modification of the nanoparticle-polymer interaction due to the presence of the surfactant.
Autores principais:Martins, P.
Outros Autores:Costa, C. M.; Benelmekki, M.; Lanceros-Méndez, S.
Assunto:PVDF Nanoparticles Ferrites Nucleation β-phase Dispersion beta-Phase
Ano:2012
País:Portugal
Tipo de documento:artigo
Tipo de acesso:acesso restrito
Instituição associada:Universidade do Minho
Idioma:inglês
Origem:RepositóriUM - Universidade do Minho
Descrição
Resumo:Ni0.5Zn0.5Fe2O4 ferrite/polyvinylidene fluoride composite films were prepared by a solution method and melt processing. As nanoparticle dispersion and polymer electroactive phase content are some of the key factors for improving magnetoelectric coupling in the composites, the dispersion of ferrite nanoparticles in the polymeric matrix was studied by preparing samples by two alternative dispersion routes: ultrasound and citric acid nanoparticle surfactation. The nucleation of the electroactive β-phase of the polymer was observed in composites produced by nanoparticle dispersion by ultrasound. This fact avoids the need of stretching composites at elevated temperature in order to obtain the electroactive phase and obtain magnetoelectric composites. By this method, nevertheless, large nanoparticle agglomerates are obtained. Nanoparticle dispersion is largely improved by citric acid surfactation of the nanoparticles. On the other hand, the β-phase of the polymer is not nucleated due to the modification of the nanoparticle-polymer interaction due to the presence of the surfactant.