高分子材料研究方法凝胶色谱法.ppt
Chap 6 Gel Chromatography,6.1 Background6.2 Principles of Gel Chromatography6.3 Data Treatment6.4 Applications on Polymers6.5 Field-Flow Fraction(FFF)Technique,GPC18601930:porous materials have adsorption-separation function(especially for dye)19401970:appearance of Liquid Chromatography 1964:The first GPC produced by Waters company1970:HPLC（rapid test、good separation effects、less sample、more sensitive）;New technology of HPLC applied in GPC area,6.1 Background,6.1 Background,Significance of Molecular Weight Distribution(MWD)Statistic Average Molecular WeightExpressions of MWDMeasurement of MWD,Relation between molecular weight and properties of polymer,6.1.2 Statistic Average Molecular Weight,Number-average Molecular WeightWeight-average Molecular Weight,6.1.2 Statistic Average Molecular Weight,Z-average Molecular WeightViscosity-average Molecular Weight,6.1.3 Expressions of MWD,ParametersBreadth parameter of molecular weight distribution:variance and standard deviation between different molecular weights and the average molecular weightPolydispersity index of molecular weight:,6.1.3 Expressions of MWD,Graphic MethodsDiscrete distribution curvesContinual distribution curves,6.1.4 Measurement of MWD,TheoriesReactions:terminal analysisThermodynamics of dilute solutions:colligative properties(boiling point elevation,freezing point depression,osmotic pressure)Kinetics:ultracentrifugal sedimentation,viscosity,volume exclusionOptical properties:scattering,6.1.4 Measurement of MWD,6.2 Principles of Gel Chromatography,High Performance Liquid Chromatography(HPLC)Gel ChromatographySeparation Mechanisms,6.2.1 HPLC,Definition High Performance Liquid ChromatographyAlso called high pressure liquid chromatographySmall particles of stationary phase:10 mHigh pressure injection pumpsAutomatic detectors,6.2.1 HPLC,ClassificationAdsorption chromatographyStationary phase:absorbentsAdsorption of mobile phaseGradient elutionApplications:additives in polymers,6.2.1 HPLC,ClassificationDistribution chromatographyLiquid-liquid chromatographyNormal phase LLC/Reverse phase LLC:polarityBonded stationary phase,6.2.1 HPLC,ClassificationIon-exchange chromatographyStationary phase:ion-exchange resinApplications:amino acids,proteins,6.2.1 HPLC,ClassificationGel chromatographyStationary phase:porous gel-like packingsLarge molecules retention value/small molecules retention value Also called“gel exclusion chromatography(GEC)”Gel permeation chromatography(GPC):organic solventGel filtration chromatography(GFC):water,GPC,Mobile phase in GPC,Mobile phase（solvents）organic solvents（THF、CHCl3、DMF）water,Gel in GPC,Kinds of gel in column crosslinked copolymer of St and DVB porous glass、porous silica、porous Al2O3 flexible material（聚醋酸乙烯酯凝胶、聚丙烯酰胺凝胶、葡萄糖凝胶）,Choice of gel(pore diameter),According to M,Column in GPC,uniform pore diameter different pore diameter 分子量范围已知，选择单一孔径；分子量范围未知，选择混合床柱,得到精确的分子量分布,探索分子量范围,6.2.1 Detectors in HPLC,InstrumentationDetectorsConcentration:refraction,UVLight Scattering/Viscosity,GPC系统之温度控制,柱温控制 environment temperature less than 50 C highest control temperature less than 150 C different solvents,different temperature（THF:35 C,DMF:85 C）,6.2.3 Separation Mechanisms,The Fundamental Equation:C:the elution volumeVM:the void volume of the mobile phaseVS:the calculative internal volume within the porous particlesK:the distribution coefficient0 K 1Very large molecules:K=0,VR=VMSmall molecules:K=1,VR=VM+VS,6.2.3 Separation Mechanisms,Equilibrium exclusion theory:suitable for most situations,Limited diffusion theory:high flow velocity,Flow separation theory:very high flow velocity,6.3 Data Treatment,Gel ChromatogramsCorrection Curve of Molecular WeightCalculation of DMWCorrection of Width of Peak,6.3.1 Gel Chromatograms,Plots:Horizontal axis:the retention values of the effluent logarithm of MWVertical axis:concentration of eluentMonodispersive samples:Gaussian distribution curvePolydispersive samples:sum of distribution curves of monodispersive samples,6.3.2 Correction Curve of Molecular Weight,Keys:Transition from VR to MWCorrection curve of molecular weight:lgM-V,6.3.2 Correction Curve of Molecular Weight,Direct Methods:Correction by monodispersive standards Exclusion limit/permeation limitAsymptote method:correction curves for wide distribution samples,单分散性标准曲线,Universal calibration method,Hydrodynamics volume,Retention volume,Flexibility of macromolecule,流体力学体积与保留体积的关系曲线具有普适性，称为普适标准曲线,=2.5NAVh/MM=2.5NAVh1M1=2M2,：特性黏数NA：阿伏伽德罗常数Vh：聚合物链等效球 的流体力学体积,K、为每一特定高分子-溶剂体系的常数,普适标准曲线,Narrow-disperse Ps as guide sample,6.4 Applications on Polymers,Applications in ProductionCopolymersBranching DegreeMeasurement of Materials of Low MoleculesAging Process,6.4.1 Applications in Production,5.4.1 Inverse Gas Chromatography,Crystallinity and Crystalization KineticsCrystallinityCrystalization Kinetics:Xc-t,6.4.2 Copolymers,Hypenation with other methods,6.4.2 Copolymers,Double Detectors,6.4.4 Measurement of Materials of Low Molecules,6.4.5 Gas Chromatography,6.5 Field-Flow Fraction(FFF)Technique,BackgroundPrinciplesExperiments,
