{"id":{"repo_id":"cape-town","oai_identifier":"oai:open.uct.ac.za:11427/9564"},"canonical_url":"https://search.dev.ndltd.org/etd/cape-town/oai:open.uct.ac.za:11427/9564","repository":{"repo_id":"cape-town","name":"University of Cape Town","base_url":"https://open.uct.ac.za/oai/request"},"display":{"title":"The synthesis of aluminium hydroxide and oxyhydroxide","abstract":"Beta alumina is a ceramic with the ability to conduct certain ions. It is conventionally formed through the high temperature solid state reaction of α-alumina with soda and lithia, which results in a mixture of β- and β\"-alumina phases. To maximise the amount of β\"-alumina formed, a second heat treatment step is required. Beta alumina may also be synthesised directly from the various aluminium hydroxide ( Al(OH)₃ ) and aluminium oxyhydroxide (AIOOH) polymorphs. The particular oxygen sublattice of the starting material is critical in determining which phases of beta alumina are formed. Boehmite and bayerite are known to yield pure β\"-alumina. In this investigation, the differences in structure and the identification of the polymorphs is discussed. A review of the methods of synthesis and concomitant mechanisms of reaction proposed in the literature are presented. Of these, the synthesis of boehmite and bayerite are investigated experimentally. Attempts to synthesise boehmite at ambient conditions resulted in the formation of pseudoboehmite, and confirmed that boehmite can only be formed by the introduction of a hydrothermal step. However, it was possible to form bayerite at ambient conditions by sμnple chemical reaction. Control of the reaction pH and the removal of inhibiting ions were found to facilitate the formation of well crystallised bayerite. Although the factors governing the successful synthesis of bayerite need further investigation, the possibility of a direct synthesis route for β\"-alumina has been demonstrated. Finally, the synthesis of β\"-alumina by the solid state reaction of the hydroxide and oxyhydroxide polymorphs was successfully completed.","abstract_html":"Beta alumina is a ceramic with the ability to conduct certain ions. It is conventionally formed through the high temperature solid state reaction of α-alumina with soda and lithia, which results in a mixture of β- and β"-alumina phases. To maximise the amount of β"-alumina formed, a second heat treatment step is required. Beta alumina may also be synthesised directly from the various aluminium hydroxide ( Al(OH)₃ ) and aluminium oxyhydroxide (AIOOH) polymorphs. The particular oxygen sublattice of the starting material is critical in determining which phases of beta alumina are formed. Boehmite and bayerite are known to yield pure β"-alumina. In this investigation, the differences in structure and the identification of the polymorphs is discussed. A review of the methods of synthesis and concomitant mechanisms of reaction proposed in the literature are presented. Of these, the synthesis of boehmite and bayerite are investigated experimentally. Attempts to synthesise boehmite at ambient conditions resulted in the formation of pseudoboehmite, and confirmed that boehmite can only be formed by the introduction of a hydrothermal step. However, it was possible to form bayerite at ambient conditions by sμnple chemical reaction. Control of the reaction pH and the removal of inhibiting ions were found to facilitate the formation of well crystallised bayerite. Although the factors governing the successful synthesis of bayerite need further investigation, the possibility of a direct synthesis route for β"-alumina has been demonstrated. Finally, the synthesis of β"-alumina by the solid state reaction of the hydroxide and oxyhydroxide polymorphs was successfully completed.","abstract_has_math":false,"creators":["Louw, Linda-Ann"],"institution":"Department of Civil Engineering","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1993,"date_issued":"1993","date_published":"1993","updated_at":"2026-07-22T22:23:19Z","subjects":[],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/11427/9564","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Louw, Linda-Ann"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-11-11T20:06:06Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-11-11T20:06:06Z"]},{"key":"dc:date.issued","label":"Date","values":["1993"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["Department of Civil Engineering"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of Cape Town"]},{"key":"dc:type","label":"Dc Type","values":["Master Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Masters"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["MSc"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["eng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/11427/9564"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Includes bibliographical references."]},{"key":"dc:description.abstract","label":"Abstract","values":["Beta alumina is a ceramic with the ability to conduct certain ions. It is conventionally formed through the high temperature solid state reaction of α-alumina with soda and lithia, which results in a mixture of β- and β\"-alumina phases. To maximise the amount of β\"-alumina formed, a second heat treatment step is required. Beta alumina may also be synthesised directly from the various aluminium hydroxide ( Al(OH)₃ ) and aluminium oxyhydroxide (AIOOH) polymorphs. The particular oxygen sublattice of the starting material is critical in determining which phases of beta alumina are formed. Boehmite and bayerite are known to yield pure β\"-alumina. In this investigation, the differences in structure and the identification of the polymorphs is discussed. A review of the methods of synthesis and concomitant mechanisms of reaction proposed in the literature are presented. Of these, the synthesis of boehmite and bayerite are investigated experimentally. Attempts to synthesise boehmite at ambient conditions resulted in the formation of pseudoboehmite, and confirmed that boehmite can only be formed by the introduction of a hydrothermal step. However, it was possible to form bayerite at ambient conditions by sμnple chemical reaction. Control of the reaction pH and the removal of inhibiting ions were found to facilitate the formation of well crystallised bayerite. Although the factors governing the successful synthesis of bayerite need further investigation, the possibility of a direct synthesis route for β\"-alumina has been demonstrated. Finally, the synthesis of β\"-alumina by the solid state reaction of the hydroxide and oxyhydroxide polymorphs was successfully completed."]},{"key":"dc:title","label":"Title","values":["The synthesis of aluminium hydroxide and oxyhydroxide"]}]}],"canonical_facts":{"dc:creator":["Louw, Linda-Ann"],"dc:date.accessioned":["2014-11-11T20:06:06Z"],"dc:date.available":["2014-11-11T20:06:06Z"],"dc:date.issued":["1993"],"dc:description":["Includes bibliographical references."],"dc:description.abstract":["Beta alumina is a ceramic with the ability to conduct certain ions. It is conventionally formed through the high temperature solid state reaction of α-alumina with soda and lithia, which results in a mixture of β- and β\"-alumina phases. To maximise the amount of β\"-alumina formed, a second heat treatment step is required. Beta alumina may also be synthesised directly from the various aluminium hydroxide ( Al(OH)₃ ) and aluminium oxyhydroxide (AIOOH) polymorphs. The particular oxygen sublattice of the starting material is critical in determining which phases of beta alumina are formed. Boehmite and bayerite are known to yield pure β\"-alumina. In this investigation, the differences in structure and the identification of the polymorphs is discussed. A review of the methods of synthesis and concomitant mechanisms of reaction proposed in the literature are presented. Of these, the synthesis of boehmite and bayerite are investigated experimentally. Attempts to synthesise boehmite at ambient conditions resulted in the formation of pseudoboehmite, and confirmed that boehmite can only be formed by the introduction of a hydrothermal step. However, it was possible to form bayerite at ambient conditions by sμnple chemical reaction. Control of the reaction pH and the removal of inhibiting ions were found to facilitate the formation of well crystallised bayerite. Although the factors governing the successful synthesis of bayerite need further investigation, the possibility of a direct synthesis route for β\"-alumina has been demonstrated. Finally, the synthesis of β\"-alumina by the solid state reaction of the hydroxide and oxyhydroxide polymorphs was successfully completed."],"dc:identifier.uri":["http://hdl.handle.net/11427/9564"],"dc:language.iso":["eng"],"dc:publisher.department":["Department of Civil Engineering"],"dc:publisher.institution":["University of Cape Town"],"dc:title":["The synthesis of aluminium hydroxide and oxyhydroxide"],"dc:type":["Master Thesis"],"dc:type.qualificationlevel":["Masters"],"dc:type.qualificationname":["MSc"]},"updated_at":"2026-07-22T22:23:19Z"}