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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Azeotropic distillation, ethanol washing, and freeze drying on coprecipitated gels for production of high surface area 3Y-TZP and 8YSZ powders: A comparative study

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Autor(es):
Piva, R. H. [1] ; Piva, D. H. [1] ; Pierri, J. J. [2] ; Montedo, O. R. K. [3] ; Morelli, M. R. [2, 1]
Número total de Autores: 5
Afiliação do(s) autor(es):
[1] Univ Fed Sao Carlos, Dept Mat Engn, Lab Ceram Synth & Formulat, BR-13565905 Sao Paulo - Brazil
[2] Univ Fed Sao Carlos, Dept Mat Engn, BR-13565905 Sao Paulo - Brazil
[3] Univ Extremo Sul Catarinense, Grp Pesquisa CERTEC, Criciuma, SC - Brazil
Número total de Afiliações: 3
Tipo de documento: Artigo Científico
Fonte: CERAMICS INTERNATIONAL; v. 41, n. 10, B, p. 14148-14156, DEC 2015.
Citações Web of Science: 6
Resumo

Coprecipitation is a well-established method for synthesizing yttria-stabilized zirconia (YSZ); however, the hard agglomerates formed during the drying stage make it difficult to obtain high surface area powders. This paper compares azeotropic distillation, ethanol washing, and freeze drying, the most common dehydration methods, and assesses their ability to yield non-agglomerated powders of coprecipitated 3 mol% Y2O3 (3Y-TZP) and 8 mol% Y2O3-stabilized zirconia (8YSZ). Azeotropic distillation most effectively increased the surface area of the powders, yielding 3Y-TZP and 8YSZ powders with specific surface areas of 94.73 and 109.37 m(2) g(-1), respectively, and crystallite sizes between 9 and 10 nm. Ethanol washing did not homogenously dry out the precipitate, whereas the freeze drying method promoted the formation of hard agglomerates, as evidenced by the peculiar powder characteristics derived from this technique. Interestingly, the surface area seems to be increased in methods that reduce the crystallization enthalpy on the hydrous zirconia precipitates. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved. (AU)

Processo FAPESP: 13/14189-8 - Revestimentos de zircônia codopada com Nb2O5/Ta2O5 + Sc2O3 como barreira térmica para aplicação em turbinas
Beneficiário:Roger Honorato Piva
Linha de fomento: Bolsas no Brasil - Doutorado