Magnetic properties of vulcanized natural rubber nanocomposites as a function of the concentration, size and shape of the magnetic fillers

Autor(es)

Bellucci, Felipe Silva ^{[1, 2]} ; Lobato de Almeida, Fabricio Cesar ^[3] ; Lima Nobre, Marcos Augusto ^[4] ; Angel Rodriguez-Perez, Miguel ^[5] ; Paschoalini, Amarildo Tabone ^[2] ; Job, Aldo Eloizo ^[4]

Afiliação do(s) autor(es)

^[1] Minist Ciencia Tecnol & Inovacao, BR-70067900 Brasilia, DF - Brazil

^[2] Univ Estadual Paulista, UNESP, Fac Engn Ilha Solteira, BR-15385000 Ilha Solteira, SP - Brazil

^[3] Univ Estadual Paulista, UNESP, Dept Biosyst Engn, BR-17602496 Tupa, SP - Brazil

^[4] Univ Estadual Paulista, UNESP, Fac Ciencias & Tecnol, BR-19060900 Presidente Prudente, SP - Brazil

^[5] Univ Valladolid, CellMat Lab, Dept Condensed Matter Phys, E-47011 Valladolid - Spain

• Tipo de documento: Artigo Científico
• Fonte: COMPOSITES PART B-ENGINEERING; v. 85, p. 196-206, FEB 2016.
• Citações Web of Science: 33

Resumo

Nickel-zinc ferrites as well as their nanocomposites formed by natural rubber are desirable because they take advantage of the thermal, mechanical and magnetic properties of each component. However, to date, the effect of the size, shape and concentration of the magnetic fillers on the magnetic properties of nanocomposite has not been studied in detail. In this report, we are presenting results about the influence of the geometric characteristic of fillers on the magnetic parameters of nanocomposites. Nickel -zinc ferrite nanopowders (NZF) with stoichionietry Ni0.5Zn0.5Fe2O4 were synthesized by a chemical route named the Modified Polyol Method (MPM) and magnetic nanocomposites were prepared with concentrations between 1 and 10 phr of ferrite nanopowders by thermal compression and hot pressing. From TEM images of ferrite nanopowders aggregates and primary particles in the nanometric scale were identified with aspect ratio different from 1 (r = a/b = 0.99, 0.55 and 0.43). From VSM measurements and particle size, the NZF may be classified as a ferrimagnetic material in a paramagnetic state and the saturation magnetization (M-S) was equal to 36.4 emu/g. Performing VSM experiments with different degrees between the sample and the magnetic field, differences up to 9% were identified for the Ms indicating a dependence of magnetic parameters on the concentration and shape of particles and aggregates. Magnetization versus time assays were carried out via VSM and two distinct relaxation times were achieved and associated with different populations of size and/or shape for the magnetic fillers. These results point to the possibility of modulation of the magnetic properties of vulcanized natural rubber composites by means of a suitable engineering process to control the concentration, size and shape of magnetic nanoparticles and agglomerates. (C) 2015 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 09/00523-8 - Preparação e caracterização de nanocompósitos multifuncionais obtidos com nanopartículas ferroelétricas e paramagnéticas em filmes de borracha natural
• Beneficiário: Felipe Silva Bellucci
• Modalidade de apoio: Bolsas no Brasil - Doutorado