Different Size Of Yttrium Oxide Superfine Powder Preparation And Modification Research

Y2O3ultrafine powder because of its excellent performance has been widely used invarious fields, but due to its smaller particle size, it is easy to get together. In this paper,through research and analysis, choose large-scale industrial production of liquid phaseprecipitation method, with low cost, environment friendly, high efficiency of thepreparation technology for the narrow particle size range, high degree of dispersion ofY2O3ultrafine powder, on this basis, Y2O3powders for surface modification processing,to improve the compatibility and dispersibility in organic phase. The main researchcontents can be summarized as follows:Using ammonia as precipitant, Y(NO3)3as yttrium source, by adding compounddispersant PEG4000and SDBS, focused on examining the amount and quality ofcomplex ratio of dispersant, reaction temperature, mole ratio of reactants, stirring speedand for the first time in the process of preparation of Y2O3and analyzes the effects ofreaction medium on the powder particle size. the results showed that when reactiontemperature is low (below15?), the amount of SDBS and PEG4000as0.4%of the totalreaction system, ratio for1:3, using anhydrous ethanol dilution of precipitant ammonia,under the high speed stirring (not less than1100r/min), Y2O3powder particle sizedistribution is narrow, the TEM observation indicated that the powder was dispersedspherical better form.Using bicarbonate as precipitant, and the introduction of ultrasound environment inpowder preparation process, focused on examining the ultrasonic power, aging treatmentapproaches, dropping methods, dispersant types and washing way on the influence of thepowder particle size, and analyzed the heat reflective properties of the different particlesize powders. The result showed that when the ultrasonic power was200W, the precursorprecipitates through high-speed centrifugation (11000r/min,10min) and a longer timeconstant temperature (40?) aging treatment, using Y(NO3)3anti dropping mode drops tothe ammonium hydrogen carbonate solution, the precipitate were treated water-ethanol-acetone three different washing methods, thus obtained powder was found by SEMobservation of uniform size, high degree of fragmentation. Using near-infrared light toexamine the powder heat-reflective properties found that uniform particle size and anarrow range of powders exhibit better heat reflection properties.Based on Y2O3ultrafine powder successful preparation, selection of oleic acid inethanol medium modified the powder obtained. Focusing on examining the modificationtemperature, the amount of oleic acid and modified time on the influence of the powder lipophilic degree, and the influence of pH on powder activation index, and comparedbefore and after the modification of powder particle size, oil absorption value anddispersion changes in organic phase. The results show that when the reaction temperaturesystem at60?-70?, oleic acid and Y2O3mass ratio is0.15:1, the reaction time is3h, atthis point Y2O3powder lipophilic degree up to65.4%; when the reaction solution pH=6,the modified Y2O3powder activation index reached a maximum value of73.9%; contrastbefore and after modified powder found that Y2O3particles of diameter D50decreased by34%, oil absorption decreased by54.2%, The modified powder in an organic solvent ofethyl acetate presented better dispersibility.