Nanocrystalline powders of yttria (8 mol.%)-stabilized zirconia have been hydrothermally synthesized from mechanical mixture of ZrO2 xerogel and crystalline Y2O3 by conventional or microwave route, respectively. The treatments have been performed at 110 and/or 150 °C for 2 h up to 72 h, and in the presence of diluted (0.2 M) or concentrated solution (2.0 M) of (KOH + K2CO3) mineralizer. To reduce the degree of agglomeration, the freshly synthesized powders has been treated under stirring with aqueous solution of poly(vinyl alcohol) (PVA 10 wt.%) for 15 h at pH 6.8, whereas to favour the formation of coating suspensions, the polymer absorbed powders and poly(ethylene glycol) (PEG) have been added to ethanol/water solution and stirred under ultrasonic agitation. With the different suspensions, various films have been deposited on glass substrates through withdrawal-coating. After drying at 60 °C and firing at 600 °C, the texture of the different films has been examined and compared with analogous films deposited by the sol-gel method. The effects of both the type of hydrothermal treatment, the concentration of the mineralizer, and the withdrawal-coating speed on the texture of the films are discussed
Films by slurry coating of nanometric YSZ (8 mol% Y2 O3) powders synthesized by low-temperature hydrothermal treatment
DELL'AGLI, Gianfranco;ESPOSITO, Serena;MASCOLO, Giuseppe;MASCOLO, Maria Cristina;
2005-01-01
Abstract
Nanocrystalline powders of yttria (8 mol.%)-stabilized zirconia have been hydrothermally synthesized from mechanical mixture of ZrO2 xerogel and crystalline Y2O3 by conventional or microwave route, respectively. The treatments have been performed at 110 and/or 150 °C for 2 h up to 72 h, and in the presence of diluted (0.2 M) or concentrated solution (2.0 M) of (KOH + K2CO3) mineralizer. To reduce the degree of agglomeration, the freshly synthesized powders has been treated under stirring with aqueous solution of poly(vinyl alcohol) (PVA 10 wt.%) for 15 h at pH 6.8, whereas to favour the formation of coating suspensions, the polymer absorbed powders and poly(ethylene glycol) (PEG) have been added to ethanol/water solution and stirred under ultrasonic agitation. With the different suspensions, various films have been deposited on glass substrates through withdrawal-coating. After drying at 60 °C and firing at 600 °C, the texture of the different films has been examined and compared with analogous films deposited by the sol-gel method. The effects of both the type of hydrothermal treatment, the concentration of the mineralizer, and the withdrawal-coating speed on the texture of the films are discussedI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
