Structured Elastomeric Submillimeter Films Displaying Magneto and Piezo Resistivity

MARIANO M. RUIZ; M. CLAUDIA MARCHI; OSCAR E. PÉREZ; GUILLERMO E. JORGE; MIRTA FASCIO; NORMA DACCORSO; MARTÍN NEGRI

JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS

JOHN WILEY & SONS INC

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

0887-6266

Structured elastomer films (100?150 mm) presenting piezo and magneto resistance are described. The films are composites of filler particles, which are both electrically con- ductive and magnetic, dispersed in an elastomeric matrix. The particles consist of magnetite (6 nm) grouped in silver-coated aggregates (Fe 3 O 4 @Ag). The matrix is styrene?butadiene rub- ber (SBR) in which diethylene glycol (DEG) is added. The par- ticles, 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 addi- tion of DEG is substantial to obtain an electrically 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.