Vacuum Drying for Ultrafine Alumina Powders |
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Authors: | Tzu-Ching Hsu |
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Affiliation: | Department of Mechanical Engineering , National Cheng Kung University , Tainan, Taiwan |
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Abstract: | It is well known that the drying of liquid-borne powders will create agglomerates and the problem of agglomeration is particularly acute in the nanoscale range. To eliminate/mitigate the agglomeration problem, in this study, a vacuum drying technique was used for drying the colloid solution with θ-Al2O3 ultrafine particles. For comparison purposes, other drying methods including oven drying, microwave drying, and freeze drying were also applied for drying of the same kind of colloid solution. The results indicate that the redispersibility, which is closely related to the degree of agglomeration, of the dried powders obtained from vacuum drying is better than that obtained from freeze drying. More surprisingly, results showed that the dried powders obtained from the vacuum drying assisted by microwave heating has the redispersibility close to 100%. |
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Keywords: | Microwave drying Ultrafine alumina powders Vacuum drying |
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