Journal of the American Ceramic Society · 1992 · 464 citations · 3 references
Natural SciencesChemical EngineeringChemistryInorganic ChemistryPhysical ChemistryReaction EngineeringCrystallization ProcessesMetal Oxide NanomaterialsMetal OxidesNucleationAqueous Salt SolutionsContinuous CrystallizationCrystallizationHydrothermal Crystal GrowthHydrothermal ProcessingHydrothermal SynthesisHydrothermal TreatmentSupercritical Fluids
Metal salt solutions were hydrolyzed in supercritical water to produce fine metal oxide particles, whose size, morphology, and crystal structure were subsequently characterized. The process yielded fine metal oxide particles in under 2 minutes, with sizes ranging from 20 to 600 nm and a relatively narrow distribution across different metal systems.
Hydrolysis of 10 metal salt aqueous solutions of 6 metal oxides was conducted in supercritical water. Continuous and rapid production of metal oxide fine particles was achieved by mixing a metal salt aqueous solution with preheated water fed from another line. The reaction time required was less than 2 min. Particle size, morphology, and crystal structure of the obtained metal (hydrous) oxides were examined. Particle size (20 to 600 nm) was different among the systems but the size range was relatively narrow in all the cases.
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