Effect of mechanochemical treatment on the synthesis of calcium dialuminate
UNSPECIFIED. (2000) Effect of mechanochemical treatment on the synthesis of calcium dialuminate. JOURNAL OF MATERIALS CHEMISTRY, 10 (4). pp. 1019-1023. ISSN 0959-9428Full text not available from this repository.
Calcium dialuminate (CaAl4O7) powders were synthesised from mechanochemically treated mixtures of aluminium hydroxide + calcium hydroxide and aluminium hydroxide + calcium carbonate. On grinding, both mixtures produce X-ray amorphous precursor phases which show Al-27 MAS NMR resonances characteristic of Al in octahedral and tetrahedral sites, and a site identified by a resonance at 37-39 ppm (possibly pentahedral Al). Although grinding does not completely destroy the carbonate XRD reflections in the carbonate mixture, both precursors show a high degree of homogeneity and behave similarly on heating, forming monophase CaAl4O7 at < 1050 degrees C. By contrast, the same unground compositions form mixtures of alpha-alumina and various calcium aluminates (but not CaAl4O7) on heating as high as 1250 degrees C. Calcium dialuminate synthesised from the carbonate-containing mechanochemical precursor had a smaller particle size which may be advantageous for subsequent fabrication and sintering.
|Item Type:||Journal Article|
|Subjects:||Q Science > QD Chemistry
T Technology > TA Engineering (General). Civil engineering (General)
|Journal or Publication Title:||JOURNAL OF MATERIALS CHEMISTRY|
|Publisher:||ROYAL SOC CHEMISTRY|
|Number of Pages:||5|
|Page Range:||pp. 1019-1023|
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