| Author(s): |
Luz, Glauber M. S.
;
Bombard, Antonio J. F.
;
Brito, Silvio L. M.
;
Gouvea, Douglas
;
Vieira, Sheila L.
;
Tao, R
Total Authors: 6
|
| Document type: | Journal article |
| Source: | ELECTRO-RHEOLOGICAL FLUIDS AND MAGNETO-RHEOLOGICAL SUSPENSIONS; v. N/A, p. 8-pg., 2011-01-01. |
| Abstract | |
Electrorheology (ER) of ferroelectric materials such as nanometric BaTiO3 is still not fully understood. In this work, nanoparticles of BaxSr(1-x)TiO3 (where x = 0.8, 0.9 or 1.0) were synthesized using the method of Pechini, calcinated at 950 degrees C, and after, lixiviated under pH 1 or pH 5. A controlled stress rheometer (MCR-301) was used to make the ER characterization of dispersions made of BaxTi1-xO3 in silicone oil (30% w/w), where (a) shear stress as a function of DC electric field (under constant shear rate) or (b) shear stress as a function of shear rate (under constant AC or DC electric field) were measured. We observed that electrophoresis occurred under electric field DC, creating a concentration gradient which induced phase separation in ER fluid. On the other hand, under AC fields above 1 kV/mm, the ER effect is stronger than for DC field, and almost without electrophoresis. Furthermore, there is an AC frequency, dependent on the disperse phase, where the ER effect has a maximum. (AU) | |
| FAPESP's process: | 05/53241-9 - Study of intergranular phenomena in ceramic materials |
| Grantee: | Reginaldo Muccillo |
| Support Opportunities: | Research Projects - Thematic Grants |