The Modification And Dispersion Research Of Nano-alumina Grain

Nano-alumina has excellent properties including high hardness, high temperature resistance, abrasion resistance, and corrosion resistance, and thus it is widely applied in industrial production area such as ceramic, semiconductor, surface coating, polishing and other fields. The nano-alumina easily cluster for their larger specific surface energy, which make the nano-alumina lost their own properties. Therefore, tt is significant to research on the nano materials cluster problem. The research of this work are as follow:(1)Try modifying the alumina grain property with mechanical grinding method by putting the pure alumina powder into planetary ball mill.(2) Produce the precursor by aluminum nitrate (aluminum hydroxide) and other additive such as ammonia, distilled water, boric acid. Mix the precursor and explosive in different proportion, and produce nano-alumina with the mixture material by detonation method.(3) carry the detonation with mixing explosive and other material such as boric acid, edible oil in the same proportion. Analyze the changed alumina properties of characterization, crystal form, appearance, particle distribution and surface groups distribution.(4)Taking anhydrous alcohol as the dispersion medium, add surfactant into the modified alumina, grind them finely, and obtain dispersed alumina solution. Analyze the dispersion suspension of alumina by sedimentation method, zeta potential and laser particle size analysis methods.The experimental results indicate that α and γ type alumina can be obtained by control the RDX proportion; the alumina synthetised by detonation are regular spheroidal, has the average particle size of50nm, absorb a large number of groups and implement the modification of surface property. Although the stable a alumina critical type cannot be changed in detonation condition, its appearance becomes regular spheroidal. The average particle sizes of detonated pure alumina mixed with boric acid and edible oil are about50nm, while that without boric acid and edible is about200nm. The coating phenomenon appears on the surface of all alumina.The property modification analysis on detonation product and pure alumina mechanochemistry methods indicate that grinding cannot change the stable a alumina critical type, but change the appearance into spherical type partly and distributed not uniformly. New groups-OH、C=O and-CH2-are generated around alumina surface. The adsorption phenomenon appeared among detonation products, grinded pure alumina and surfactant. The alumina particles, which are larger in alcohol, are about300-600nm, some are1μm, which proves that the accumulating phenomenon appears in alcohol. The dispersion experimental results of modified alumina by grinded indicate that the particle size in basic oil is about100nm; the alumina generated from detonation production can stay dispersion situation for1month, while the grinded alumina are unstable dispersion system in the basic oil, and subside in different degree.