Preparation And Properties Of Polyaniline Composite Nanoparticles Er Fluid

As to the electrorheological fluids, when add an applied electric field, it's apparent viscosity sharply increased in milliseconds, shear strength and elastic modulus increased significantly. Material's properties are controled continuously by the applied electric field. The strength of materials increase with the applied field's strength. The material quickly restored to their original state when the external electric field is removed. Electrorheological fluids have potential applications in engineering technology, such as shock absorbers, controling valves and other fields. However, due to inadequate performance of electrorheological materials, such as the shear strength is low, rapid sedimentation rate and other factors, severely restricted the industrial application of ER technology. In this condition composite nano-particle ER fluid rapidly developed. According to Dielectric polarization theory, staring from the physical design parameters of ER fluid materials,preparation of inorganic nanoparticles with different morphologies, and modificate of particles surface with polar organic. Polyaniline has high thermal stability, and density, in particular permittivity and conductivity of polyaniline can be adjusted on demand. In this paper, nanoparticles of long rod of titanium dioxide,particulate barium titanate, inorganic molecular sieve pore bodies as substrate, its surface modified by polyaniline coating, While mediation particle morphology and its density to improve stability, on the other hand to play the high particle dielectric properties, such particulates can enhance the dielectric and the base oil does not match, thus expected to preparation of excellent ER fluid.1,PANI/TiO2 composite electrorheological fluid Preparation and Electrorheological PropertiesTitanium dioxide (TiO2) becomes the focus of ER materials because of its high dielectric constant and easily to synthesize nano-particles. Hydrothermal method and the solution polymerization are two ways to prepare nano-TiO2 and PANI/TiO2 composites. By Fourier transform infrared (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and so on characterized the nano-TiO2. And test the mechanical response of ER fluid by rotary rheometer in steady shear and dynamic scanning. The results show that:TiO2 and PANI are connected by chemical bonds, TiO2 nano-particles as long rod-like morphology, the yield stress of T1O2 ER fluids was 300Pa. The yield stress of PANI/TiO2 ER fluids has doubled, leakage current has greatly reduced and the system exhibits the phenomenon of shear thinning. With the increasing concentration of solid particle, shear stress and apparent viscosity increase accordingly. Dynamic scan study the influence of material's viscoelastic by stress, frequency, strength of electric field.2,PANI/BaTiO3 composite electrorheological fluid Preparation and Electrorheological PropertiesBy sol-gel prepared barium titanate nano-particles and situ composite technology prepared polyaniline/barium titanate nano-composite particles. Composite particles were characterized by FT-IR, XRD, SEM and other methods. Rotary rheometer test the composite electrorheological fluid in steady shear and mechanical properties under dynamic scanning. The results show that:BaTiO3 nano-particles are random spherical. X-ray diffraction pattern of PANI/BaTiO3 shows that still have the crystal structure of BaTiO3. BaTiO3 particles have weak ER effect and the yield stress is only 85Pa. Composite particle ER fluid has a high dielectric constant, the yield stress ratio of BaTiO3 electrorheological fluid increases an order of magnitude and have good insulation properties. The shear stress increases with the increase of electric field strength and shear thinning phenomenon is significant. Storage modulus is the dominant parameter in system. With the electric field intensity increases, the composite particles and amino silicone oil connected with hydrogen bonds. After 100h only sedimented 10%, effectively improved the sedimentation stability of the system.3,PANI/MCM-41 composite electrorheological fluid Preparation and damper ApplicationHydrothermal synthesis method is used to synthesize mesoporous molecular sieve of MCM-41.Using MCM-41 mesoporous molecular sieve pore characteristics of monodisperse as'nano-reactors', in its channel doping of polyaniline synthesized in acid to alkali treatment by the anti-doping state PANI/MCM-41 particles as dispersed particles, Silicone oil as a dispersion medium of ER fluid. With XRD, FTIR, FSEM analyze particle morphology and structure. ER studies its effect and influence factors, such as the electric field strength, shear rate and so on. Experiments show that:MCM-41 has a unique fingerprint-like and long-range pore structure. MCM-41 ER fluid yields stress of 240Pa. The ER effects of PANI/MCM-41 ER fluid were significant with increasing the strength of electric field. The highest yield stress is up to 4000Pa. At 70℃the leakage current is 0.13mA. The prepared ER fluids are used in automotive shock absorber simulation experiment, and measure its vibration reduction.