Investigations On The Preparation Technologies Of ?-Al₂O₃ Nano-powders

?-Al₂O₃ nanometer materials have been widely used in the fields such as electronics,material.In this paper,used Aluminum-air Battery Discharge by-Product as raw materials,nano ?-Al₂O₃ powders were prepared via ammonium sulfate pyrolysis,ammonium aluminum sulfate pyrolysis,AACH pyrolysis and Sol-Gel method respectively,obtained the optimum conditions of preparing oxides nanoparticles.On the basis of ?-Al₂O₃ powders preparation,prepared the nano ?-Al₂O₃ dispersion via grafting modification.Ammonium sulfate pyrolysis method was employed to prepare the nano ?-Al₂O₃ powders with Aluminum-air Battery Discharge by-Product and ammonium sulfate as raw materials,SDS as dispersant.The effect of the calcination temperature,ball milling,the addition of ammonium sulfate and SDS to the structure and morphology of nano ?-Al₂O₃ was studied.The result showed that,Discharge Product,ammonium sulfate and DSD was added at the same time,then ball milling,the ?-Al₂O₃ particle with average particle size 300 nm was obtained via calcined at 1200?.Ammonio-aluminum pyrolysis method was employed to prepare the nano ?-Al₂O₃ powders with sulfuric acid,ammonium sulfate and Aluminum-air Battery Discharge by-Product as raw materials,PEG as dispersant.The effect of the temperature and the amount of acid for the discharge by-product dissolve was studied,the preparation technology of Ammonio-aluminum,calcination condition to the performance of nano ?-Al₂O₃ was also studied.The result showed that,employ the ethanol sedimentary method to prepare Ammonio-aluminum,the high dispersion ?-Al₂O₃ with average particle diameter 50 nm obtained via calcined at 1200?.AACH pyrolysis method was employed to prepare the nano ?-Al₂O₃ powders with sulfuric acid,ammonium carbonate and Aluminum-air Battery Discharge by-Product as raw materials,PEG as dispersant.The influence of reactant dropping speed and calcination conditions on the precursor and nano ?-Al₂O₃ dispersion was studied,a new process?termed as double step calcination method?for synthesizing nano ?-Al₂O₃ powder was suggested.The results show that,the pure AACH precursor can be achieved when the dropping speed of aluminum sulfate is less than 16 m L.min-1,when the precursor is heated at the low temperature of 300? first,and then calcined at the high temperature of 1200?,the high dispersion ?-Al₂O₃ can be get with average particle diameter 50 nm.Sol-Gel method was employed to prepare the nano ?-Al₂O₃ powders with Aluminum-air Battery Discharge by-Product as raw materials,with citric acid,chromotropic acid and catechol as complexing agent.The effect of the types of complexing agent,mass of complexant,calcining conditions,pH value to the performance of nano ?-Al₂O₃ was studied.The results show that,When complexing ratio of the citric acid and aluminum ion was 2:1,using PEG as isolation agent and through the sun lamp irradiation to prepare the gel,the high dispersion nano ?-Al₂O₃ particle with average particle diameter 50 nm was obtained via calcined at 1200? for 1h.Graft modification method was employed to prepare the nano ?-Al₂O₃ dispersion with the ?-Al₂O₃ prepared by AACH pyrolysis as raw materials,titanate and silane coupling agent?KH-550?,polyacrylic acid ammonium?PAANH4?as modifying agent.The effect of the modifying agent type to the dispersion of nano ?-Al₂O₃ was discussed.The results show that via mechanical ball milling disperse method with adding the appropriate titanate and PAANH4 respectively can remove the most of aggregates of ?-Al₂O₃ and obtain nano ?-Al₂O₃ oil dispersion with average particle diameter 45 nm and aqueous dispersion with average particle diameter 80 nm.