Design And Synthesis Of The Er Material And Performance

Electrorheological (ER) materials have brought more and more attention due to its potential applications in many fields, such as automotive engineering, hydraulic pressure industry, the mechanical manufacturing industry, the sensor technology and so on. In order to understand clearly the mechanism of the electrorheolagical effect and obtain good ER materials which are suitable in practical application, the inorganic, organic and composite materials have been studied. Based on the current investigation in ER materials, in this paper, three types of ER materials [p-cyclodextrin (P-CD) inclusion, p-cyclodextrin di-carboxyl acid and other organic compounds], in which including thirteen kinds of the materials, have been synthesized, their ER properties and the influence of the composition, microstructure and dielectric properties on ER effect of a material were studied by ER test, XRD, IR, Thermal analysis, anti-sedimentation stability and dielectric property analyses.The results showed that: ① The ER performance of p-cyclodextrin or P-cyclodextrin derivative material can be improved by forming the inclusion compound between host (P-cyclodextrin) and guest;②The dielectric loss of a material plays a more important role than its dielectric constant, in influencing the ER effect of a particle material. The material, which has better ER property, possesses larger dielectric loss and dielectric constant ordinary;③The ER performance of a material can be enhanced by doping some rare earth ions which can induce the lattice distortion and defects, due to the modification in the dielectric and conduction properties of the material;④The ER property can change with doping different metal ions, and there is a optimal value on the doping degree, the ER activity of the material would decrease when the doping degree went beyond the limit.The experimental results indicated that: among the materials prepared by us, the suspension (25% weight fraction) of the material with a P-CD:PTA:Y(NO₃)₃ of 1:2:0.2 (molar ratio) (PTA= p-toluenesulfonic acid) presents a significant shear stress of 2.3 kPa and the relative shear stress value reaches 47.4, which is 13.3 times as much as that of P-cyclodextrin, at E=4.2 kV/mm and γ=150s^-1. The β-CD-PTAinclusion compound material doped with carbon fibre (25% weight fraction) also presents a significant shear stress of 3.02 kPa and the relative shear stress value reaches 27.1 at E=4.2 kV/mm and y=150s" , this material may be applied in automotive absorber. In addition, the P-cyclodextrin di-carboxyl acid inclusion and its rare earth complexes materials and so on also prossess higher ER activity.