Improvement of thermal stability of porous nanostructured ceramic membranes

Journal Article · Thu Mar 31 23:00:00 EST 1994 · Industrial and Engineering Chemistry Research; (United States)

DOI:https://doi.org/10.1021/ie00028a012· OSTI ID:7108377

Lin, Y S; Chang, C H; Gopalan, R ^[1]

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1. Univ. of Cincinnati, OH (United States). Dept. of Chemical Engineering

Unsupported crack-free lanthana-doped alumina and titania membranes and yttria-doped zirconia membrane were prepared by the sol-gel method. A novel solution-sol doping method was employed to coat the dopant oxide on the grain surface of these nanostructured ceramic membranes. The pore and phase structure data of these membranes after heat treatment from 450 to 1,100 C under an atmosphere of air and a steam/air mixture show a substantially improved thermal and hydrothermal stability of these doped ceramic membranes. Doping lanthana (in [gamma]-alumina and titania membranes) and yttria (in zirconia membrane) raises the [gamma]-alumina to [alpha]-alumina, anatase to rutile, and tetragonal zirconia to monoclinic zirconia phase transformation temperature by about 200 C (for alumina), 150 C (for titania) and 300 C (for zirconia), respectively. At temperatures lower than the phase transformation temperatures, doping retards the surface area loss and pore growth of the three membranes. For the three ceramic membranes investigated, the effects of stabilizing the pore structure decrease in the following order: zirconia > titania > [gamma]-alumina.

• OSTI ID: 7108377
• Journal Information: Industrial and Engineering Chemistry Research; (United States), Journal Name: Industrial and Engineering Chemistry Research; (United States) Vol. 33:4; ISSN IECRED; ISSN 0888-5885
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360200* -- Ceramics
Cermets
& Refractories
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CHALCOGENIDES
CRYSTAL-PHASE TRANSFORMATIONS
DOPED MATERIALS
HEAT TREATMENTS
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
MATERIALS
MEMBRANES
MICROSTRUCTURE
OXIDES
OXYGEN COMPOUNDS
PHASE STUDIES
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
PORE STRUCTURE
RARE EARTH COMPOUNDS
STABILITY
THERMODYNAMIC PROPERTIES
TITANIUM COMPOUNDS
TITANIUM OXIDES
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES