Preparation Of Titanium Oxide Nanocomposite And Study Of Electrorheological Properties

Electrorheological fluid or ER fluid as we all know is mianly two phase fluid composed by polarizable nanoparticle which are dispersed at an insulating oil,the ER properties would occur instantly and reversebly under the applied electric field that we add,and the reason why this phenomenon happen is that the formation of chain-like or column-like structures between adjacent polarized nanoparticles along the direction of electric field.Because of the researcher we study which is ER fluid can react rapidly and reversibly to the applied electric field,the ER fluid can be widely used in shock absorbers,clutches and brakes.but with the rapid development of the ER field,it also come with some restrictive problems such as low polarization force,temperature dependence,suspension leakage current or particle precipition.to overcome above problems,researchers have developed a variety of ER materials in various forms,the most important of which are non-polar semiconductor materials and conductive polymers.And among them,TIO₂ is one of the most popular and the hottest materials in the field of research at present.TiO₂ have lots of advantages such as high dielectric constant,good thermal stability,diversity of preparation and biocompatibility,etc.which make it become one of the best ER materials.However,the ER effect produced by TiO₂ is limited to its insufficient yield stress and poor anti-precipitation performance.Therefore,we designed a composite material with TiO₂ to cover different materials,so as to form a core-shell structure.The core-shell structure nanoparticle also gradually attracted more and more attention due to its own advantage properties.It is made up by two kinds of nanoparticles,one of which is a core?internal material?and the other is a shell?external coating material?.Because of the coat of the external materials,the dielectric property and poor thermal stability of internal materials could change,so as to improve the overall stability,dispersion and anti-precipitation properties of the whole core-shell structure.At last,the core-shell structure nanoparticle will show some unique characteristics different from the two composite materials.There are so many research objects in the core-shell field,including organic coat organic matter,inorganic coat organic matter,inorganic coat inorganic matter and so on.And TiO₂become one of the important members in the field of core-shell research due to its own good properties.In this experiment,we choose to coat H₂Ti₂O₅ and MoS₂ with the TiO2 in order to improve the ER properties of core-shell nanocomposites.The main experiment contents and major results are given as follows:1:we first used titanium dioxide and sodium hydroxide solution as raw materials and successfully prepared the titanium nanotube H₂Ti₂O₅ by hydrothermal method,and we used it as the matrix to coat the titanium oxide on the outside in order to prepare the titanium oxide@H₂Ti₂O₅ core-shell nanoparticles by the solvent heat method.Then the morphology and crystal structure are observed by TEM,SEM,and XRD.Finally,the titanium oxide@H₂Ti₂O₅ core-shell nanoparticles were dispersed in the silicon oil to form the ER liquid,which showed a outstanding ER effect in the test with the electronrheological rheometer.2:In the first step we prepare a lamellar molybdenum disulfide by the chemical stripping method,and used it as a carrier to coated with titanium dioxide by the hydrolyzed method.Finally we got a MoS₂@TiO₂ nanocomposites particle,and prepared ER fluid by using it as dispersed phase.The surface morphology and crystal structure of the composite particles were characterized by SEM and XRD.The morphology of the composite particles was uniform by SEM we observed.At the same time,the shear stress of the ER fluid prepared by the composite particles increased obviously under different electric fields,which showed a strong ER effect.3:The iron alkoxide/titanium oxide nanocomposites were prepared by a two step method in this paper.Then the produced nanocomposite particle were dispersed in the silicone oil in order to obtain a series electrorheological?ER?fluids.The high-temperature heat reflux method was used to prepare a iron alkoxide template firstly,and then hydrolysis method and solvothermal method were adopted,espectively,to fabricate iron alkoxide/titanium oxide nanocomposite particles.The XRD,SEM,electrorheometer instrument were used to investigate the structure characterization and properties of nanocomposite particles.The influence of different kinds of surfactants mixture system on the ER activities of nanocomposite particles was studied.By contrast,the nanocomposites prepared by hydrolysis method are better not only in morphology but also in ER properties compared with hydrothermal method.