The Preparation Of Barium Titanate/graphite Oxide Composite Particles And Their Electrical Response Properties

The Electrorheological(ER)elastomers are mainly composed of dispersed particles and macromolecular networks.The ER elastomer with high electrical response can be obtained by improving the performance of dispersed particles.Barium titanate(BT)is a common electric field responsive material.In order to overcome these shortcomings,make better performance of the new electric response elastomer.Our team has done a series of studies,by doping and modification of surface on the BT material,obtained by BT as the main body of the composite materials.Particle composition,structure and morphology are influential on the electric field response of the material performance.In this paper,on the basis of preliminary work in the laboratory,uniform BT particles of 300?500 nm were prepared by hydrothermal method.The modified BT particles were made to contain positively charged amino groups on the surface,which were combined with negatively charged graphite oxide(GO).The BT/GO composites were successfully prepared by electrostatic self-assembly method by adjusting the reaction conditions.Scanning electron microscopy(SEM)and transmission electron microscopy(TEM)were used to observe the morphology of the composite particles,discussed the optimum conditions for the synthesis of composite particles.The crystal phase and bonding mode of the composite particles were characterized by infrared spectroscopy and X-ray diffraction.Thermogravimetric analysis and impedance analyzer were used to compare the thermal stability and dielectric properties of the composite particles.On this basis,this paper also obtained a series of composite materials by regulating the oxidation degree,size and coating amount of GO.To analyze composite particles electric response performance,under the same conditions,the composite particles dispersed in gelatin/glycerol to prepared composite hydrogels,the dynamic viscoelasticity spectrometer can measure electric field and electric field hydrogels storage modulus of the elastomer,calculating rate and energy storage modulus of the elastomer difference,through the comparison and analysis,the effects of GO on the electric field response of BT/GO composites were discussed from different perspectives.The results show that:1.From the SEM and TEM images,it can be seen that GO is completely coated on the surface of BT.By XRD of different composite particles,the cubic phase of BT particles did not change before and after the coating.2.The thermal stability of the composite particles is good.Because of the addition of GO,composite particles' dielectric constant is slightly lower than that of pure BT.3.In the composite particles coated with GO of different sizes,GO and ultrafine graphite oxide(UGO)were completely coated on the surface of BT.Among them,the GO covering the multiple particle,UGO are mainly covered in a single particle.Electric field response performance of composite particles were higher than pure BT particles,and BT/UGO particle dielectric constant is higher than the BT/GO particles,electric field response performance is also better,energy storage modulus rate is about 15%.4.Compared the GO coated composite particles with different oxidation degrees,the higher the oxidation degree is,the higher the dielectric constant of the composite particles is,but both are lower than the pure BT particles.At the same time,the higher the oxidation degree is,the higher the increment and increment sensitivity of the elastomer will be,and the better the electric field response performance of the composite particles will be.5.For the prepared composite particles with different shell contents,with the increase of shell contents,the increment and increment sensitivity of the elastomer first increase and then decrease,which indirectly indicates that the electrical response performance of the particles first increases and then decreases.The purpose of this paper is to explore the optimal synthesis conditions of BT/GO core-shell composite particles.On the basis of improving the dispersion stability of BT,the influence of GO on the electric field response performance of the composite particles is explored from the aspects of content,size and carbon-oxygen ratio,which provides some basis for the preparation of new electrorheological materials with better properties.