Engineering Materials

Thisbookistalkingabouthowtousesupercriticalwater(SCW)torapidlyproduce micro- and nano-particles of metal oxides, inorganic salts, metals and organics. Itcoversbasicprinciples,experimentalmethodologiesandreactors,particlep- duction,characterizationsandapplicationsaswellastherecentadvancement. Fine particlescanbeproducedbybothchemicalandphysicalprecipitationofproducts from SCW. They can be used as catalysts, materials in ceramics and electronic devices andcompositematerials. Particlesareeasilyproduced continuouslyina owreactorinshortreactiontimes(0. 4s?2min)butcanalsobesynthesizedin batchreactorsforlongreactiontimes(e. g. ,12h). Theycanbeeasilystudiedin-situ microscopically(optical/IR/Raman/SR-XRD)inanopticalmicro-reactor,diamond anvilcell. Thesize,sizedistribution,crystalgrowth&structure,andmorphologyof particlescanbecontrolledbychangingtheconcentrationsofstatingmaterials,pH, pressures,temperatures,heating&coolingrates,organicmodi cations,reducingor oxidizingatmospheres, owratesandreactiontimes. Thisisthe rstbooktosystematicallyintroduceusingSCWforproductionof neparticles. Itisanidealreferencebookforengineers,researchersandgraduate studentsinmaterialscienceandengineering. vii Acknowledgments I would like to thank Drs. T. Ogi & T. Minowa (Biomass Technology Research Center,NationalInstituteofAdvancedIndustrialScienceandTechnology,Japan), and Profs. K. Arai, H. Inomata, R. L. Smith Jr. and T. Adschiri (Chemical Engineering,TohokuUniversity,Japan),whoinitiallyintroducedthehydrothermal andsupercritical uidsareastomewhenIworkedinJapanfrom1996to1999. Thanks are also due to Profs. J. A. Kozinski, R. I. L. Guthrie (Materials Engineering,McGillUniversity,Canada)andI. S. Butler(Chemistry,McGill)for theirguidanceinmyworkonhydrothermalprocessduringmyworkinCanadafrom 1999to2007. Profs. W. Bassett (Geological Sciences, Cornell University) and D. Baker (Earth&PlanetarySciences,McGill)forinstructionsregardingDAC,Dr. I-Ming Chou(U. S. GeologicalSurvey)forusefuldiscussionsofthepressurecalculation procedure. Drs. M. Watanabe and T. Sato (Research Center of Supercritical Fluid Technology, Tohoku University, Japan) for discussions about the experimental set-upofthebatchand owreactors. Drs. S. Xu,H. Assaaoudi,R. HashaikehandA. Sobhy,whoworkedwithmeat McGillinCanada. ix Contents 1 Introduction...1 1. 1 Background ...1 1. 2 RapidExpansionofSupercriticalSolution(RESS)Process ...4 1. 3 SupercriticalAntisolvent(SAS)Process ...4 1. 4 OtherPhysicalProcesses ...5 1. 5 SupercriticalWaterProcess ...5 References...8 2 Supercritical Water Process...11 2. 1 Introduction ...11 2. 2 BatchReactor ...15 2. 3 FlowReactor...18 2. 4 DiamondAnvilCell(DAC)...20 References...25 3 Metal Oxides Synthesis...29 3. 1 Introduction ...29 3. 2 Boehmite(AlOOH) ...30 3. 3 Ferrites...31 3. 4 Phosphor(YAG) ...32 3. 5 LiCoO /LiMn O ...33 2 2 4 3. 6 Ce Zr O (x =0?1)...33 1?x x 2 3. 7 PotassiumHexatitanate,PotassiumNiobateandTitania ...35 3. 8 ZincOxide...38 3. 9 Nickel,Nickel/CobaltOxide...