"Structured elastomeric submillimeter films displaying magneto and piezo resistivity?

RUIZ, M.M.; MARCHI, M.C.; PÉREZ, O.E.; JORGE, G.; FASCIO, M.; D´ACORSSO, N.; NEGRI RICARDO MARTÍN

JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS

JOHN WILEY & SONS INC

Lugar: New York; Año: 2015 vol. 53 p. 574 - 586

0887-6266

ABSTRACT Structured elastomer films (100-150 m) presenting piezo and magneto resistance are described. The films are composites of filler particles which are both electrically conductive and magnetic, dispersed in an elastomeric matrix. The particles consist of magnetite (6 nm) grouped in silver coated aggregates (Fe3O4@Ag). The matrix is styrene-butadiene-rubber (SBR) in which diethylene glycol (DEG) is added. The particles, SBR and DEG are dispersed in toluene and then placed between two rare earth magnets. Formation of pseudo-chains (needles) of inorganic material, aligned in the direction of the magnetic field is obtained after solvent evaporation. The addition of DEG is substantial in order to obtain an electrical conductive material. The electrical conductivity is anisotropic and increases when applying normal stresses and/or magnetic fields in the direction of the needles. The elastomers, particles and needless were characterized by XRD, SEM, EDS, FTIR, DSC, TGA, VSM, profilometry and stress-strain analysis. KEYWORDS: Structured Elastomers; Magnetoresistive Composites; Piezoresistive Elastomers.