The nanosized particle materials of doped-TiO_2 with Y_2O_3 were prepared by means of sol-gel technique for use in electrorheological (ER) fluids, and their crystal structures were measured by X-ray diffraction (XRD) ...The nanosized particle materials of doped-TiO_2 with Y_2O_3 were prepared by means of sol-gel technique for use in electrorheological (ER) fluids, and their crystal structures were measured by X-ray diffraction (XRD) analysis. To compare with the pure TiO_2, a distinct enhancement in the shear stress under dc electric field was found by using such materials. This can be explained by the increase of the dielectric loss and dielectric constant at low frequency. The effects of the crystal structure of the particles on the dielectric property and ER performance of materials were investigated.展开更多
The SiO_2 particle material has weak electrorheological (ER) activity. The ER performance of the SiO_2 particles can be ameliorated after adsorbing Y_2(CO_3)_3. In this paper, the effect of Y_2(CO_3)_3 and different s...The SiO_2 particle material has weak electrorheological (ER) activity. The ER performance of the SiO_2 particles can be ameliorated after adsorbing Y_2(CO_3)_3. In this paper, the effect of Y_2(CO_3)_3 and different surfactants on the ER performance of the SiO_2 particle materials is investigated. The results show that anionic or cationic surfactants maybe enhance the ER activity of SiO_2 material, and nonionic surfactants cannot when surfactants are added during the process of the SiO_2 particle preparation, only the anionic surfactant, AES, can enhance markedly the ER performance of the material. The surface area, pore volume and pore diameter of the particles were measured. The effect of Y_2(CO_3)_3 and the surfactants on the microstructure of SiO_2 materials and the relationship between ER effect and the microstructure are described.展开更多
The SiO 2 adsorbing YF 3, Y 2(CO 3) 3, Y 2(C 2O 4) 3 and YPO 4, respectively, formed four systems of particle materials: SiO 2·YF 3, SiO 2·Y 2(CO 3) 3 , SiO 2·Y 2(C 2O 4) 3 and SiO ...The SiO 2 adsorbing YF 3, Y 2(CO 3) 3, Y 2(C 2O 4) 3 and YPO 4, respectively, formed four systems of particle materials: SiO 2·YF 3, SiO 2·Y 2(CO 3) 3 , SiO 2·Y 2(C 2O 4) 3 and SiO 2·YPO 4. The electrorheological(ER) behavior of the electrorheological fluids (ERF) prepared by dispersing them in silicone oil was tested at 20 ℃ under d.c. field. The results show that the system of SiO 2·YF 3 does not display ER activity, and the ER performance of the particle materials of SiO 2·Y 2(CO 3) 3 is the best among them. The shearing stress of ERF with SiO 2·Y 2(CO 3) 3 particles is 1.644 KPa and the relative viscosity η r(=η E/η 0) is 20.3 (under field strength E=4200 V·mm -1) while the adsorbed content of Y 2(CO 3) 3 in the SiO 2 particle materials is 12.4%(mass fraction).展开更多
文摘The nanosized particle materials of doped-TiO_2 with Y_2O_3 were prepared by means of sol-gel technique for use in electrorheological (ER) fluids, and their crystal structures were measured by X-ray diffraction (XRD) analysis. To compare with the pure TiO_2, a distinct enhancement in the shear stress under dc electric field was found by using such materials. This can be explained by the increase of the dielectric loss and dielectric constant at low frequency. The effects of the crystal structure of the particles on the dielectric property and ER performance of materials were investigated.
文摘The SiO_2 particle material has weak electrorheological (ER) activity. The ER performance of the SiO_2 particles can be ameliorated after adsorbing Y_2(CO_3)_3. In this paper, the effect of Y_2(CO_3)_3 and different surfactants on the ER performance of the SiO_2 particle materials is investigated. The results show that anionic or cationic surfactants maybe enhance the ER activity of SiO_2 material, and nonionic surfactants cannot when surfactants are added during the process of the SiO_2 particle preparation, only the anionic surfactant, AES, can enhance markedly the ER performance of the material. The surface area, pore volume and pore diameter of the particles were measured. The effect of Y_2(CO_3)_3 and the surfactants on the microstructure of SiO_2 materials and the relationship between ER effect and the microstructure are described.
文摘The SiO 2 adsorbing YF 3, Y 2(CO 3) 3, Y 2(C 2O 4) 3 and YPO 4, respectively, formed four systems of particle materials: SiO 2·YF 3, SiO 2·Y 2(CO 3) 3 , SiO 2·Y 2(C 2O 4) 3 and SiO 2·YPO 4. The electrorheological(ER) behavior of the electrorheological fluids (ERF) prepared by dispersing them in silicone oil was tested at 20 ℃ under d.c. field. The results show that the system of SiO 2·YF 3 does not display ER activity, and the ER performance of the particle materials of SiO 2·Y 2(CO 3) 3 is the best among them. The shearing stress of ERF with SiO 2·Y 2(CO 3) 3 particles is 1.644 KPa and the relative viscosity η r(=η E/η 0) is 20.3 (under field strength E=4200 V·mm -1) while the adsorbed content of Y 2(CO 3) 3 in the SiO 2 particle materials is 12.4%(mass fraction).
