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Please use this identifier to cite or link to this item: http://acervodigital.unesp.br/handle/11449/76725
Title: 
Flexible magnetic membranes based on bacterial cellulose and its evaluation as electromagnetic interference shielding material
Author(s): 
Institution: 
  • Universidade Federal do Rio de Janeiro (UFRJ)
  • Universidade Estadual Paulista (UNESP)
ISSN: 
0928-4931
Abstract: 
Flexible magnetic membranes with high proportion of magnetite were successfully prepared by previous impregnation of the never dried bacterial cellulose pellicles with ferric chloride followed by reduction with sodium bisulfite and alkaline treatment for magnetite precipitation. Membranes were characterized by Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), vibrating magnetometer, field emission scanning electron microscopy (FEG-SEM) and impedance spectroscopy. Microwave properties of these membranes were investigated in the X-band (8.2 to 12.4 GHz). FEG-SEM micrographs show an effective coverage of the BC nanofibers by Fe 3O4 nanoparticles. Membranes with up to 75% in weight of particles have been prepared after 60 min of reaction. Magnetite nanoparticles in the form of aggregates well adhered to the BC fibers were observed by SEM. The average crystal sizes of the magnetic particles were in the range of 10 ± 1 to 13 ± 1 nm (estimated by XRD). The magnetic particles in the BC pellicles presented superparamagnetic behavior with a saturation magnetization in the range of 60 emu g- 1 and coercive force around 15 Oe. These magnetic pellicles also displayed high electrical permittivity and a potential application as microwave absorber materials. © 2013 Elsevier B.V.
Issue Date: 
1-Oct-2013
Citation: 
Materials Science and Engineering C, v. 33, n. 7, p. 3994-4001, 2013.
Time Duration: 
3994-4001
Keywords: 
  • Bacterial cellulose
  • Magnetite and electromagnetic wave absorbers
  • Electrical permittivity
  • Electromagnetic interference shielding materials
  • Electromagnetic wave absorber
  • Field emission scanning electron microscopy
  • Impedance spectroscopy
  • Superparamagnetic behavior
  • Vibrating magnetometers
  • Cellulose
  • Chlorination
  • Chlorine compounds
  • Electromagnetic pulse
  • Field emission microscopes
  • Fourier transform infrared spectroscopy
  • Magnetism
  • Magnetite
  • Ore reduction
  • Saturation magnetization
  • Superparamagnetism
  • X ray diffraction
  • Membranes
Source: 
http://dx.doi.org/10.1016/j.msec.2013.05.035
URI: 
Access Rights: 
Acesso restrito
Type: 
outro
Source:
http://repositorio.unesp.br/handle/11449/76725
Appears in Collections:Artigos, TCCs, Teses e Dissertações da Unesp

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