Preparation Of Rod-like Titanate Particles And Electrorheological Property

Electrorheological?ER?fluid is composed of polarizable particles and dispersion medium,under the action of applied electric field,the viscosity of the dispersion system has changed dramatically,the dispersed particles arranged in chains or columnar after polarization and the dispersion system show the class nature of the solid,controlling the viscosity of fluids is interesting because of the potential usage in sensor,clutch and other intelligent equipment.The electrorheological materials are varied,such as inorganic,organic particles and composite particles and so on.SiO₂/TiO₂ nanocomposite particles and fibrous one-dimensional titanate particles were prepared,and the electrorheological effect was tested.SiO₂/TiO₂ nano particles of different thickness of coating layer were prepared by chemical precipitation,pH value of the reaction liquid was controlled 8-9 range,which is not only environmentally friendly but also getting the compact cladding layer.When Na2SiO3 concentration in the range of 0.2 to 0.5 mol/L,the thickness of coating layer?d?meet the direct ratio?C?formula d = 8.88 + 3.572 C.When the concentration is more than 1.0 mol/L,SiO₂ piled up together.But electrorheological properties to disappear due to the thickness and closely coating layer cannot be polarization under the electric field.Titanate particles were prepared by hydrothermal reaction with titanium dioxide and sodium hydroxide,the conditions of preparation stage: the alkali concentration is 10 mol/L,the reaction time is more than 10 h,temperature of reaction is 200°C,the post-processing phase conditions: calcination temperature is 300°C,calcined heating rate of 5°C/min,the holding time 3h,then we get solid fibrous titanate particles.Changing the hydrothermal time,we get a radius of 100-300 nm,the length of 5-15 mm?5<L/D<40?and the radius is 200-400 nm,the length of 10-20 mm?25<L/D< 60?fibrous particles,respectively,and test its electrorheological properties,the small length to diameter ratio of fibrous particles was got the larger yield stress and failure recovery ability of circulation.Compared with raw material titanium dioxide,fibrous particles dispersion stability was improved obviously,Continuouly observing samples for 48 h,we found that the back scattered light and transmitted light changed little,and the dispersion stability was better than raw materials.