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1Application of Inorganic Chemistry in IndustryFlat Glass and Coatings On GlassDr Troy ManningAdvanced Technologist, On-line CoatingsPilkington European Technical CentreHall LaneLathomUK第1页/共75页第一页，共76页。2OutlineOverview of Flat Glass industry and NSG/PilkingtonFlat Glass manufactureFloat Glass ProcessCoating technology within the glass industryChemical Vapour DepositionExamples of on line coating applicationsLow Emissivity/Solar ControlSelf CleaningSummarySuggested Reading第2页/共75页第二页，共76页。3Global Flat Glass MarketGlobal Market 37 million tonnes (4.4 billion sq. m)Building Products 33 m tonnes - Automotive 4m tonnesOf which 24 million = high quality float glass 3 million = sheet 2 million = rolled 8 million = lower quality float (mostly China)Global Value At primary manufacture level 15 billionAt processed level 50 billion第3页/共75页第三页，共76页。4NSG and Pilkington combinedA global glass leader the pure play in Flat GlassCombined annual sales c. 4 billionEqual to Asahi Glass in scale, most profitable in Flat GlassOwnership/interests in 46 float lines6.4 million tonnes annual outputWidened Automotive customer base36,000 employees worldwideManufacturing operations in 26 countriesSales in 130+ countries第4页/共75页第四页，共76页。5Manufacture of Flat Glass Four main methods Plate Glass (1688) molten glass poured on to a flat bed, spread, cooled and polished Sheet Glass (1905) continuous sheet of glass drawn from tank of molten glass Rolled Glass (1920) molten glass poured onto to two rollers to achieve an even thickness, making polishing easier. Used to make patterned and wired glass. Float Glass (1959) molten glass poured onto bed of molten tin and drawn off in continuous ribbon. Gives high quality flat glass with even thickness and fire polish finish. 320 float-glass lines worldwide第5页/共75页第五页，共76页。6Melting furnaceFloat bathCooling lehrContinuos ribbon of glassCross cuttersLarge plate lift-off devicesSmall plate lift-off devicesRaw material feedThe Float-Glass ProcessOperates non-stop for 10-15 years6000 km/year0.4 mm-25 mm thick, up to 3 m wide第6页/共75页第六页，共76页。7The Float Glass Process第7页/共75页第七页，共76页。8Raw materials第8页/共75页第八页，共76页。9Melting Furnace第9页/共75页第九页，共76页。10Float Bath第10页/共75页第十页，共76页。11Float Glass Plant第11页/共75页第十一页，共76页。12The Float-Glass ProcessFine-grained ingredients, closely controlled for quality, are mixed to make batch, which flows as a blanket on to molten glass at 1500 C in the melter. The furnace contains 2000 tonnes of molten glass.After about 50 hours, glass from the melter flows gently over a refractory spout on to the mirror-like surface of molten tin, starting at 1100C and leaving the float bath as a solid ribbon at 600C. Despite the tranquillity with which float glass is formed, considerable stresses are developed in the ribbon as it cools. 第12页/共75页第十二页，共76页。13Raw MaterialsOxide % in glass Raw material sourceSiO272.2SandNa2O13.4Soda Ash (Na2CO3)CaO8.4Limestone (CaCO3)MgO4.0Dolomite (MgCO3.CaCO3)Al2O31.0Impurity in sand, Feldspar or CalumiteFe2O30.11Impurity in sand or Rouge (Fe2O3)SO30.20Sodium sulphateC0.00Anthracite第13页/共75页第十三页，共76页。14Raw materials SiO2Very durable, BUT high melting point (1700C)!+ Na2OMelts at a lower temperature, BUT dissolves in water!+ CaOMore durable, BUT will not form in bath without crystallisation+ MgOGlass stays as a super-cooled liquid in bath, no crystallisation+ Al2O3Adds durability+ Fe2O3Adds required level of green colour for customer第14页/共75页第十四页，共76页。15Chemistry of GlassImportant glassmaking chemistry: basic reactionsNa2CO3 + SiO2 1500C Na2SiO3 + CO2Na2SiO3 + x SiO2 Na2SO4 (Na2O)(SiO2)(x+1)Digestion第15页/共75页第十五页，共76页。16Composition of Glass第16页/共75页第十六页，共76页。17Structure of GlassRandom network of SiO4- tetrahedral units.Na-O enter Si-O network according to valency Network FormersCa and Mg Network Modifiers make structure more complex to prevent crystallisation 第17页/共75页第十七页，共76页。18Body-tinted GlassIonResulting Colour of GlassFerrous (Fe2+)BlueFerric (Fe3+)YellowFe2+ + Fe3+GreenSelenium (SeO2)BronzeCobalt (Co2+)Grey/BlueNickel (Ni2+)Grey第18页/共75页第十八页，共76页。19CIE L a* b* colour space第19页/共75页第十九页，共76页。20CIE L a* b* colour space第20页/共75页第二十页，共76页。21Functions of a Window Light in homes, offices Light out shops, museum displays Heat in heating dominated climates Heat out cooling dominated climates Can change properties of glass by applying coatings to the surface第21页/共75页第二十一页，共76页。22Making a window functional - coatings A wide variety of coating technologies are utilised by the glass industry Spray Pyrolysis Powder Spray Chemical Vapour Deposition Sputter Coating Thermal Evaporation Coatings Sol Gel Coatings These are applied On Line i.e. as the glass is produced on the float line Off Line i.e. coating not necessarily produced at the same location第22页/共75页第二十二页，共76页。23Variations of CVD Atmospheric Pressure APCVD Low Pressure - LPCVD Aerosol Assisted - AACVD Metalorganic MOCVD Combustion/Flame CCVD Hot Wire/Filament HWCVD/HFCVD Plasma Enhanced - PECVD Laser Assisted LACVD Microwave Assisted MWCVD Atomic Layer Deposition ALD第23页/共75页第二十三页，共76页。24Chemical Vapour Deposition第24页/共75页第二十四页，共76页。25Chemical Vapour DepositionMain gas flow regionGas Phase ReactionsSurface DiffusionDesorption of Film PrecursorBy ProductsDiffusion to surface第25页/共75页第二十五页，共76页。26Chemical Vapour DepositionAnimation kindly supplied by Dr. Warren Cross, University of Nottingham第26页/共75页第二十六页，共76页。27CVD processes and parametersProcessParametersTransportPrecursorsGas phase reactionPressure, temperature, flow conditions, boundary layer thickness, gas phase concentration, precursors, carrier gasDiffusionPressure, temperature, flow conditions, boundary layer thickness, gas phase concentrationAdsorptionTemperature, gas phase concentration, number and nature of sitesSurface reactionTemperature, nature of surfaceDesorption of by-productsTemperature, pressure, nature of surfaceDiffusion to lattice siteTemperature, surface mobility, number of vacant sites第27页/共75页第二十七页，共76页。28CVD Precursor Properties Volatile gas, liquid, low melting point solid, sublimable solid Pure Stable under transport React/Decompose cleanly to give desired coating minimise contaminants Can be single source or dual/multi-source第28页/共75页第二十八页，共76页。29CVD Precursors Single Source pyrolysis (thermal decomposition) Ti(OC2H5)4 TiO2 + 4C2H4 + 2H2O (400 C) Oxidation SiH4(g) + O2(g) SiO2(s) + 2H2(g) Reduction e.g. WF6(g) + 3H2(g) W(s) + 6HF(g) Dual source e.g. TiCl4(g) + 4EtOH(g) TiO2(s) + 4HCl(g) + 2EtOEt(g)第29页/共75页第二十九页，共76页。30Dual Source and Single Source PrecursorsFilmDual Source Single SourceGaAsGaCl3 + AsH3Me2Ga(AsH2)TiNTiCl4 + NH3Ti(NMe2)4WSiWCl6 + SiH4W(SiR)4TiO2TiCl4 + H2OTi(OiPr)4CdSeCdMe2 + H2SeCd(SeR)2第30页/共75页第三十页，共76页。31Transport of Precursors Bubbler for liquids and low melting solids Direct Liquid Injection syringe and syringe driver for liquids and solutions Sublimation for solids hot gas passed over heated precursorAerosol of precursor solutions4 .24)760( ppVFVa第31页/共75页第三十一页，共76页。32Effect of Temperature on Growth RateRTEAka lnlnIndependent of temperature第32页/共75页第三十二页，共76页。33Flow conditionsLaminar Flow regimeTurbulent Flow Regime第33页/共75页第三十三页，共76页。34Reynolds Number Dimensionless number describing flow conditionsuLRe Mass density related to concn and partial pressureu = average velocity= viscosityL = relevant length, related to reactor dimensionsIf Re 1000 fully turbulent flowReality is between the two extremesforces viscous fluidforces inertial fluid第34页/共75页第三十四页，共76页。35Dimensionless Numbers Reduces the number of parameters that describe a system Makes it easier to determine relationships experimentally For example: Drag Force on a SphereVariables: Force = f (velocity, diameter, viscosity, density)Can be reduced to 2 “dimensionless groups”:Drag coefficient (CD) and Reynolds number (Re)228 uLFCD uLRe第35页/共75页第三十五页，共76页。36Dimensionless NumbersLaminar flow regimeTurbulent flow regimeExperimental values of CD for spheres in fluid flows at various Re第36页/共75页第三十六页，共76页。37Boundary Layer gas velocityFrictional forces against reactor walls decrease gas velocity 2132 uLLd The boundary layer thickness can be estimated from:第37页/共75页第三十七页，共76页。38Boundary Layer - temperatureContact with hot surfaces increases temperature第38页/共75页第三十八页，共76页。39Boundary Layer precursor concentrationDepletion of precursor decreases gas phase concentration第39页/共75页第三十九页，共76页。40Nucleation and GrowthVan der Waals type adsorption of precursor to substratePrecursors then diffuse across surfacePrecursors diffuse across boundary layer to surfaceAnd can be desorbed back into main gas flowOr can find low energy binding sites to coalesce into filmMain Gas Flow第40页/共75页第四十页，共76页。41Nucleation and GrowthSubstrate TemperatureGrowth RateSurface DiffusionCrystallinityLowHighSlow relative flux of precursorsAmorphous no crystalline structureHighLowFast relative to flux of precursorsEpitaxial replicates substrate structureIntermediateIntermediateIntermediatePolycrystalline第41页/共75页第四十一页，共76页。42Growth Mechanisms(b) Frank - van der MerweLayer growth(c) Stranski - KastanovMixed layered and island growth(a) Volmer - WeberIsland growth第42页/共75页第四十二页，共76页。43Thin Film Analysis Many techniques are used to characterise thin films Examples include XRD crystallinity, phase XRR layer thickness, layer roughness SEM/EDX/WDX morphology, thickness, composition Raman phase, bonding FTIR phase, bonding XPS composition, depth profiling, doping SIMS composition, depth profiling, doping AFM roughness, surface morphology TEM crystalline structure, crystal defects Analysis of functional properties第43页/共75页第四十三页，共76页。44CVD on GlassFor on-line coating of glass we require: High growth rates required thickness in 100 nm/s possible Low precursor efficiency 10%SiCxOy (70 nm)SnO2:F (350 nm)GlassSiH4 + C2H4 + CO2 SiCxOy + H2O + other by-productsUsed as colour suppression and barrier layer第56页/共75页第五十六页，共76页。57Low Emissivity CoatingGenerally based on SnO2:F (Transparent Conductive Oxide)SiCO under layer used as colour suppressant第57页/共75页第五十七页，共76页。58Low-E and Solar Control Coatings第58页/共75页第五十八页，共76页。59Self-Cleaning GlassTwo mechanisms:Super hydrophilicityPhotocatalytic degradation of organic matter.TiO2 coating第59页/共75页第五十九页，共76页。60SuperhydrophilicityOxygen vacanciesTiO-TiOTiHTiTiTiH+TiOTiOTiTiOTiOTiHHH2O(OH-, H+)Water dropletsUniform water filmUV illumination timeContact angleooooooodarkUV第60页/共75页第六十页，共76页。61Photocatalytic ActivityUltra band gap irradiation of TiO2 Generation of electron hole in valence bandHole migrates to the surface and results in oxidation of organic materialValence BandConductance BandOxidationReductionAA+BB-h+h第61页/共75页第六十一页，共76页。62Semi-conductor PhotocatalysisA. Mills, S Le Hunte, J. Photochem. Photobiol A, 1997, 108, 1-35.第62页/共75页第六十二页，共76页。63CVD of ActivTMSiO2 (30 nm)TiO2 (17 nm)GlassSiH4 + O2 + C2H4 SiO2 + by-productsUsed as barrier layer to prevent diffusion of Na ions into TiO2 layerTiCl4 + EtOAc TiO2 + HCl + organic by-productsLaminar Flow regimeReasonable growth rates and precursor efficiency第63页/共75页第六十三页，共76页。64ActivTM第64页/共75页第六十四页，共76页。65ActivTM第65页/共75页第六十五页，共76页。66ActivTM第66页/共75页第六十六页，共76页。67Superhydrophilicity15 mins UV Exposure30 mins UV Exposure45 mins UV ExposureBefore UV Exposure第67页/共75页第六十七页，共76页。68Photocatalytic Effect UV-AbsorptionO2 -OH*Organic SoilGlassBarrier LayerTiO2 - Layer第68页/共75页第六十八页，共76页。69Photocatalytic EffectThe photoactivity of the coating can be measured by monitoring the decomposition of a standard contaminant A thin film of stearic acid (n-octadecanoic acid, 200) is applied from a methanol solution onto the coating Stearic acid used as a typical organic contaminant FTIR (Fourier transform infra-red spectroscopy) used to detect C-H stretch of stearic acid C-H absorption intensity measured after varying UV exposureOO第69页/共75页第六十九页，共76页。70Stearic Acid DecompositionC-H Absorption Zero UV exposureC-H Absorption 60 mins UV exposure2 340nm第70页/共75页第七十页，共76页。71Pilkington ActivTM第71页/共75页第七十一页，共76页。72Summary Scale of the Global Flat Glass Industry Manufacturing Flat Glass Float Glass Process Coating Glass Chemical Vapour Deposition Examples of commercial glazing coatings prepared by CVD第72页/共75页第七十二页，共76页。73Recommended Reading D.W. Sheel and M.E. Pemble Atmospheric Pressure CVD Coatings on Glass, ICCG4 2002 M.L. Hitchman, K.F. Jensen Chemical Vapor Deposition Academic Press, 1993 W.S. Rees, CVD of Non-metals, VCH, Weinheim, 1996 M. Ohring The Materials Science of Thin Films, Academic Press, 2001第73页/共75页第七十三页，共76页。74First in Glass第74页/共75页第七十四页，共76页。75感谢您的观看(gunkn)！第75页/共75页第七十五页，共76页。NoImage内容(nirng)总结1。SiO272.2Sand。Na2O13.4Soda Ash (Na2CO3)。CaO8.4Limestone (CaCO3)。MgO4.0Dolomite (MgCO3.CaCO3)。SO30.20Sodium sulphate。C0.00Anthracite。Reduction e.g. WF6(g) + 3H2(g) W(s) + 6HF(g)第七十六页，共76页。
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