Preparation And Electrorheological Properties Of TiO₂/Carbon Nitride Based Nanocomposites

Electrorheology is the study of a class of substances whose rheological properties of polar particles change from liquid characteristics to solid characteristics under the action of an electric field with a certain field strength.And this change is reversible and rapid,and this phenomenon is generally called electrorheological effect.These polar particles-based fluids are called electrorheological fluids,or ER fluids for short.Carbon nitride materials are characterized by the special electron structure,grand physical and chemical pros,rich microstructure（from bulk particles to quantum dots）,it is valued by researchers in the field of energy catalysis,but the research in the field of electrorheology is rarely reported.Titanium dioxide,as a traditional and classic electrorheological material,is widely used in the field of electrorheological testing due to the high dielectric constant,stable polarization ability,abundant preparation methods,and non-toxicity.However,due to its poor polarization ability,poor stability,and very limited yield strength under the action of an electric field,the monodisperse system cannot be used in the market.Therefore,complex and varied morphological structures have been proposed,such as nano-scale core-shell structures,interlayer cladding structures,etc.By inspired on thus,in this paper,the specific research will be parted to three parts on following:In Chapter 2,the composite particles of bulk carbon nitride nanosheets had been obtained by using the stencil method and TiO₂ hollow nano-microspheres（C₃N₄Nanosheets/TiO₂ Hollow Microspheres）by high temperature ultrasonic method.The results display the electrorheological fluid composed of nano-hollow titanium oxide microspheres with a core-shell structure and a nano-sheet structure carbon nitride framework with rich porosity has excellent electrorheological properties,outstanding resistance to breakdown,and an obvious plateau region.The response speed to electric field is fast and the degree of reversibility is high,which conforms to the characteristics of awesome electrorheological materials,and the synthesis is easy-going,which provides a meaningful reference example for the application field of electrorheological materials in the future.In Chapter 3,the ER fluids based on Co-C₃N₄NSs/TiO₂NPs was successfully prepared.The results showed that TiO₂NPs were successfully adhered in the interlayer structure of Co-C₃N₄NSs,and the prepared Co-C₃N₄NSs had higher and larger specific surface area,the particle size of the composite material is small and uniform,and the interlayer composite structure is complete and clear.The electrorheological performance test shows that the electrorheological effect and electrorheological efficiency of Co-C₃N₄NSs/TiO₂NPs are significantly higher than those of conventional electrorheological materials（up to 196）.In Chapter 4,anis-CN/TiO₂NRs composites with rod-like nanostructures was compounded by a two-step method,and characterized their morphology,structure,molecular information,and crystal structure by many kinds of proof methods.Moreover,the anis-CN/TiO₂NRs-based ER fluid exhibits excellent electrorheological properties and ultra-high stability.In the electrorheological test,its own sensitivity and reversibility to electric field are very good,and the dielectric properties analysis results are also very good.It is proved by its own ultra-high electrorheological efficiency.