Papers by Author: Hong Yan Guo

Abstract: This paper emphasis has researched the effect of particles scattering, surrounding thickness, heat treatment temperature and etc on microstructure, mechanics properties and macrostructure under different electric field of Ni/TiO₂, Ni/TiO₂/PAn Particles ER fluid, It is found that particles scattering, surrounding thickness, heat treatment temperature have major effect on shear stress and chain of particles.

Abstract: By means of mechanical properties test，the relationship among shear ratio, concentration and electric field, magnetic field, electromagnetic field on the Ni/TiO2/SDBS EMR fluid properties have been analyzed. It had found that with increasing shear ratio，the shear stress of Ni/TiO2/SDBS EMR fluid increased for same composition, but there is a critical value. With increasing concentration，the property of EMR fluid increased for same shear ratio. Coupling electromagnetic field makes the properties improve.

Abstract: By means of mechanical properties test and microstructure observation,the relationship between mechanical properties ,microstructure graph of core-shell Ni/TiO₂ group particles concentration of EMR and different electric field, magnetic field or electric-magnetic field have been researched. It is found that with increasing of particles concentration, the properties are increased. But there is a critical range value, too high or too low particles concentrations are harmful to properties and microstructure. The best particles concentration of Ni/TiO₂ particles is about 30%. In the same field with increasing concentration, particles chain of electrorheological fluid under certain electric field become more strong,brawnier and interweaved each other.

Abstract: This paper emphasis has researched the ER properties of Ni group core-shell nano particles modifier with Urea，SDBS and other polar molecule，analysis the relationship among ER properties and polar molecule type ，compound modifier under different electric field or magnetic field. It is found that the shear stress increasing with adding polar molecule, compound polar molecule modify can marked advance the properties of Ni group core-shell particles ER fluid.

Abstract: By means of structure analysis, mechanical properties test and microstructure observation，structure of Ni and Ni/TiO₂ group particles have been obtained, the relationship among partic_{Subscript textSubscript text}le diameter，electric field strength and shear ratio of the properties of Ni/TiO₂ group core-shell particles ER fluid have been researched. It has been found that with increasing particle diameter，the shear stress of ER fluid decreased, and with increasing shear ratio，the shear stress of ER fluid increased for same diameter particle and composition ER fluid. At same time, the smaller of particle diameter, the higher of ER properties such as shear stress, but there is a critical value for shear ratio, when shear ratio is larger than critical value, the properties of ER is nearly a value for same composition ER fluid. Particles chain of ER fluid under certain electric field is different with diversity Ni group Particles.

Abstract: By means of mechanical properties test，the relationship among shear ratio, concentration and electric field, magnetic field ,electromagnetic field on the Ni/TiO2 group electrorheological fluid properties have been analyzed. It is found that with increasing shear ratio，the property of electrorheological fluid increased for same composition ER, but there is a critical value. With increasing concentration，the property of electrorheological fluid increased for same shear ratio. Coupling electromagnetic field makes the properties improve.

Abstract: By means of mechanical properties test and microstructure graph observation，the relationship of heat treatment temperature of core-shell Ni/TiO2 group particles with mechanical properties under different electric field has been researched .It is found that the FT-IR，XRD morphology of heat treatment at350°C is different from the one at100°C，the shear stress of same composition ER decreased with heat treatment temperature increasing. But the leakage current density of ER shows contrary result. That is because the leakage current density of ER decreased with the increasing heat treatment temperature.

Abstract: Electrorheological (ER) fluids are regarded as smart materials with potential for application in various industries because of the controllable viscosity, the reversibly and fast response. In this paper, core-shell structured Ni/Ti/Urea nanoparticles, as an ER material, were prepared by a sol-gel method. TEM, XRD and FT-IR spectra demonstrated that the Ni nanoparticles have been homogeneously coated with a 2 nm thick layer of TiO2 containing polar groups. The polar groups were caused by the introduction of urea. The ER effect of the fluids of Ni/Ti/Urea particles in silicone oil was investigated under a DC electric field. It is found that the ER fluids of the urea-doped Ni/TiO2/Urea particles have a high ER activity, which is 10 times that of the particles containing no urea. The polar groups in the particles are the intrinsic reasons for the enhancement of electrorheological effect.

Abstract: By means of mechanical properties test and microstructure graph observation，the effect of core-shell Ni/TiO2 particles size, concentration on the properties and morphology of electrorheological fluid was emphatically studied, It is found that with concentration increasing the properties of electrorheological fluid can be improved, but there is a critical value, Urea content of Ni/TiO2 particles is 30%, in the same field with increasing concentration, particles chain of electrorheological fluid become strong，coarse and interweaved each other. The smaller of particle size, the higher of shear strength of electrorheological fluid.