Study On The Preparation And Properties Of The Shuttle Boehmite Sheet And Its Secondary Structure

The shuttle-shaped boehmeth has wide application prospects in the preparation of catalysts and catalyst supports due to its special morphology and large surface area.High-purity boehmite materials are precursors of high purity alumina,which can be used for the preparation of crystalline materials such as sapphire.At present,the main method of synthesis of the shuttle-shaped boehmite is to use surfactants and morphology inducers.However,the addition of such reagents not only complicates the preparation process,increases the cost of preparation,but also may cause the presence of residual organic carbo,which makes the purity of boehmite sheet greatly reduced.Thus,this synthesis method can not meet the requirements for the preparation of high-purity alumina materials.In this paper,the shuttle boehmite sheet and its secondary structure were prepared by a template-free hydrothermal method.This method is simple and will not introduce other compound,which meet the requirement of the preparation of high purity alumina material,catalysts and catalyst supports.In this paper,the technology of size control has been obtained through the systematic study of the preparation conditions,and the two-class cambiform structure is prepared by controllable synthesis.Because of its large surface area and special topography,it shows excellent performance in ink-jet printing as the ink absorbing material.This paper systematically investigates the effects of hydrothermal temperature,hydrothermal time,species of inorganic aluminum salts,concentration of aluminum nitrate and sodium acetate,acid and alkali of solution on the properties of the materials.By investigating the systems of ammonium acetate and sodium acetate,this paper proposes the formation mechanism of shuttle boehmite and its secondary structure.The research contents and conclusions are as follows:(1)this paper uses sodium acetate or ammonium acetate as precipitating agent without adding any surfactants to synthesize the shuttle boehmite sheet and its secondary flower and spindle structure,uses XRD,FESEM,Malvern,FTIR analytical method to characterize the prepared samples,investigates the effects of reaction conditions on the phase,morphology,particle size,purity,specific surface area and pore volume of the boehmite,and explores the nucleation,growth,and self-assembly processes.(2)The prepared cambiform ?-AlOOH architectures were applied into ink-jet printing as a kind of ink absorbing material and compared with commonly used flake-like hydrated alumina materials at the same time.Color ink-jet printing paper was prepared according to the same process and the printing test was done.After that,the quality of ink-jet printing was measured through four kinds of evaluation indexes,including gloss,color density,clarity and weather resisting property.The results show that,the amount of cambiform ?-AlOOH architectures could be remarkably reduced when reaching the same printing quality,and cambiform ?-AlOOH architectures would have promising application prospects in the field of ink-jet printing.(3)By investigating the two systems of ammonium acetate and sodium acetate,the self-assembly mechanism of secondary structure boehmite was proposed: the surface energy is changed due to the inorganic anion adsorbed to boehmite surface.At the same time,inorganic anion can reduce the repulsion between the particles of boehmites,and the boehmite are assembled together under the action of van der Waals and hydrogen bonding between the hydroxyl group forces to form a secondary structure.