Hydrothermal synthesis of well-crystallised boehmite crystals of various shapes

Aluminium monohydroxide, also known as aluminium oxyhydroxide (boehmite - AlO[OH]), is water insoluble but crystallises into microcrystals of various shapes. When, by X-ray diffraction, the microcrystals present a basal reflexion (d[020]) of 0.611 nm, the crystalline structure is referred to as &quo...

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Bibliographic Details
Main Authors: Pérsio de Souza Santos, Antonio Carlos Vieira Coelho, Helena de Souza Santos, Pedro Kunihiko Kiyohara
Format: Article
Language:English
Published: Associação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol) 2009-01-01
Series:Materials Research
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Online Access:http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392009000400012
Description
Summary:Aluminium monohydroxide, also known as aluminium oxyhydroxide (boehmite - AlO[OH]), is water insoluble but crystallises into microcrystals of various shapes. When, by X-ray diffraction, the microcrystals present a basal reflexion (d[020]) of 0.611 nm, the crystalline structure is referred to as "well-crystallised" boehmite. Natural and synthetic crystals of well-crystallised boehmite can have a plate-like shape with either a rhombic or hexagonal profile. Synthetic crystals can also be lath-like or ellipsoid in shape. The purpose of this paper is to present a method of hydrothermal synthesis using a single temperature (200 ºC) for preparing plate-like crystals of well-crystallised boehmite with ellipsoid, rhombic, hexagonal, and lath-like profiles by using different precursors. Our observations suggest that all of these shapes are stages of growth of the microcrystals of well-crystallised boehmite along the c-axis direction of the rhombic crystals.
ISSN:1516-1439