Electrorheological Properties of α-Bi2O3 and Bi2O2CO3
| Autor: | S. V. Golodukhina, A. V. Egorysheva, T. V. Gerasimova, A. S. Kraev, O. M. Gaitko, A. V. Agafonov |
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| Rok vydání: | 2019 |
| Předmět: |
010302 applied physics
Materials science Yield (engineering) Polydimethylsiloxane General Chemical Engineering Metals and Alloys Nanoparticle 02 engineering and technology Dielectric 021001 nanoscience & nanotechnology 01 natural sciences Inorganic Chemistry chemistry.chemical_compound chemistry Electric field 0103 physical sciences Ultimate tensile strength Materials Chemistry Dielectric loss Composite material 0210 nano-technology Polarization (electrochemistry) |
| Zdroj: | Inorganic Materials. 55:344-354 |
| ISSN: | 1608-3172 0020-1685 |
| Popis: | —We have synthesized needle- and platelike α-Bi2O3 and Bi2O2CO3 nanoparticles. The bulk density of the α-Bi2O3 and Bi2O2CO3 powders is 8.5 and 6.9 g/cm3. The dielectric permittivity of α-Bi2O3 and Bi2O2CO3 has been calculated using dielectric permittivity and dielectric loss tangent dispersion measurements in the frequency range from 2.5 × 101 to 1 × 106 Hz for 40% suspensions (0.05 and 0.08 volume fractions of α-Bi2O3 and Bi2O2CO3, respectively) in PMS-300 polydimethylsiloxane. The value of e∞ has been found to be 5.4 for α-Bi2O3 and 4.9 for Bi2O2CO3. Dielectric spectra of the suspensions have been shown to exhibit no relaxation behavior in the frequency range studied. We have compared the effects of the shape and dielectric permittivity of the particles on the magnitude of the electrorheological effect in them. Using a simple polarization model, we have analyzed the effect of the dielectric characteristics of the filler material on the yield stress τ0 of the suspensions in electric fields from 0 to 4 kV/mm. Using a combination of rheometric and direct microscopic observations, we have explained the effect of the type of filler on the electrorheological effect: the Bi2O2CO3-based ERFs have higher shear and compressive yield stresses, whereas the α-Bi2O3-based ERFs have a higher tensile yield stress. |
| Databáze: | OpenAIRE |
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