Hydrothermal synthesis of novel alpha alumina nano-materials with controlled morphologies and high thermal stabilities
Following a strong demand for novel α-Al 2 O 3 nano-materials with unique properties, both pure and doped nano-sheets, nano-needles, and nanosized equiaxed particles (reference) of 100% phase-pure α-Al 2 O 3 , were synthesized at 430-450 °C under 10.3 MPa pressure by the hydrothermal treatment of bo...
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Veröffentlicht in: | CrystEngComm 2010-01, Vol.12 (1), p.2996-32 |
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Format: | Artikel |
Sprache: | eng |
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Zusammenfassung: | Following a strong demand for novel α-Al
2
O
3
nano-materials with unique properties, both pure and doped nano-sheets, nano-needles, and nanosized equiaxed particles (reference) of 100% phase-pure α-Al
2
O
3
, were synthesized at 430-450 °C under 10.3 MPa pressure by the hydrothermal treatment of boehmite powder (γ-AlOOH) in the presence of α-Al
2
O
3
seeds and 1-10% morphology modifiers. SiO
2
and H
3
BO
3
were used as morphology modifiers to produce phase pure α-Al
2
O
3
nano-sheets and nano-needles, respectively, that exhibited strong crystallographic
c
- and
a
-faceting and BET surface areas up to 40 m
2
g
−1
stable above 1000 °C. A mesocrystal growth mechanism of the α-Al
2
O
3
nano-particles was observed. Unprecedented flexibility to control the sizes and morphologies of α-Al
2
O
3
enabled fabrication of 90% porous ceramics with unique pore geometries and pore volumes up to 1.5 cm
3
g
−1
. These novel α-Al
2
O
3
nano-materials can be useful in a variety of catalytic applications, nano-filtration, chemical-mechanical planarization, composites,
etc.
Hydrothermally synthesized α-Al
2
O
3
nano-sheets and nano-needles, prepared in the presence of SiO
2
and H
3
BO
3
morphology modifiers, respectively, exhibit strong crystallographic
c
- or
a
-faceting with high BET surface areas up to 40 m
2
g
−1
that are temperature stable above 1000 °C. |
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ISSN: | 1466-8033 1466-8033 |
DOI: | 10.1039/b927192a |