The Preparation, Stability And Ceramic Surface Coating Modification Of Alumina Sol

In this thesis, the aluminum sol was prepared by alcoholate hydrolysis method, thealuminum isopropoxide was used as raw material. The formation process andmorphology of aluminum sol was investigated by Two-step alcoholate hydrolysis method;The optimal process conditions of preparation was determined through orthogonal tests;The stability of aluminum sol was studied by single factor experiment method.The aluminum sol, taking a lead, was utilized to coat the ceramic surface to improvethe property of anti-fouling on the premise of having no influence on color andglossiness of ceramic as a result of its remarkable properties of anno size, no-toxic,well-compatible and helping sintering. This kind technique of preparing aluminum solhas been used in industry production in Foshan red lion ceramics co., LTD.The main research work and conclusions:(1) The optimal process conditions, which determined by researching the influenceof hydrolysis temperature, reaction time, acid/glycol ratio and water/glycol ratio on thestability of aluminum sol systemically through orthogonal tests, was shown as below:hydrolysis temperature was at80℃; The ratio of nitric acid to isopropanol aluminummole was1.5; the hydrolysis time was controlled about60min; water/alcohol ratio was200. On this basis, by changing the way of hydrolysis, in Two-step hydrolysis ofalcoholate preparation of alumina sol. Two-step hydrolysis of alcoholate was carried outto study the alumina sol formation process and morphology, which could control theprocess of hydrolysis of alcoholate effectively. The prepared aluminum sol had a uniformand smaller particle size; the size distribution was between30nm to80nm,50nm inaverage. The mechanism of Two-step hydrolysis of alcoholate was discussed,preliminarily.(2) Single factor test was adopted to investigated the factor of aluminum sol stability,for instances particle size, viscosity, pH and the Zeta potential, which affected by Hydrolysis temperature, the ratio of acid to alcohol and water alcohol ratio. The resultsshown the Hydrolysis temperature was the most significant factor: it not only influencedthe alumina sol viscosity, particle size, pH and Zeta potential, but the whole process ofhydrolysis reaction. Acid and AIP ratio has a distinct effect on the particle size of thealuminum sol: the size of the aluminum sol could be changed by adjusting the rationfrom1.5to2.0. Water and AIP ratio has little effects on the particle size, pH of the sol,but has a remarkable effect on alumina sol viscosity and transparency: within areasonable range, the dosage of alumina sol viscosity and transparency could be adjustedby water volume.(3) The aluminum sol, which described above, was utilized to coat ceramic surfaceto produce the anti-fouling ceramics. The best parameters of coating technique, whichobtained by research of effect of viscosity of sol and coating times to the anti-foulingperformance of ceramic and the tests of anti-fouling and cleaning, was determined asbelow: the alumina sol viscosity was15mPa·s, the coating times was two.