物理藥劑學(xué)ppt精選課件

.,Colloidaldispersionsystem,.,Classificationofdispersedsystembasedonparticlesize,.,TypesofColloidaldispersion,.,Lyophiliccolloids,Systemscontainingcolloidalparticlesthatinteracttoanappreiableextentwiththedispersionmediumarereferredtoaslyophilic(solvent-loving)colloids.hydrophilicsols:gelatin,acacia,insulin,albuminLipophiliccolloids:rubber,polystyrene.Amaterialthatformsalyophiliccolloidalsysteminoneliquid(e.g.water)maynotdosoinanotherliquid(e.g.benzene).,.,.,.,Lyophobiccolloids,Lyophobiccolloidsiscomposedofmaterialsthathavelittleattraction.e.g.gold,silver,sulfur,arsenoussulfide,andsilveriodide.,.,Themethodstopreparelyophobiccolloids,Dispersionmethods1,grindingmethod2,sonicationdispersionmethod3,arcdischargemethodCondensationmethods1,physicalmethods2,chemicalmethods,.,grindingmethod,.,sonicationdispersionmethod,.,arcdischargemethod,Owingtotheintenseheatgeneratedbythearc,someofthemetaloftheelectrodesisdispersedasvapor,whichcondensestoformcolloidalparticles.,.,Physicalcondensationmethods,1,replacementofsolvent,.,Physicalcondensationmethods,2,Steamquenchmethod,.,chemicalcondensationmethods,2H3AsO3（w）+3H2SAs2S3（sol）+6H2OFeCl3（w）+3H2O（H）Fe(OH)3（sol）+3HCl2H2S(w）+SO2(g)2H2O+3S(sol）Na2S2O3+2HCl2NaCl+H2O+SO2+S(sol)2HAuCl4+3HCHO+11KOH2Au(sol）+3HCOOK+8KCl+8H2O,.,Solpurification,1,dialysismethod2,ultrafiltration,.,dialysismethod,Semipermeablemembrane,.,dialysismethod,Electrodialysis,.,ultrafiltration,Semipermeablemembrane,.,ultrafiltration,Electroultrafiltration,.,Associationcolloids,.,CMC,thecriticalmicelleconcentration(CMC)isdefinedastheconcentrationofsurfactantsabovewhichmicellesformandalladditionalsurfactantsaddedtothesystemgotomicelles.,.,Typeofmicelle,CylindricalmicelleBilayerBilayervesicleInvertedmicelleMicrotubule,.,Classificationandtypicalexamplesofassociationcolloids,.,Propertiesofsurface-activeagentsshowingchangesthatoccursharplyattheCMC,.,PredicttheCMCofthemixture,Todeterminetheminimumamountofsurfactant,.,Opticalpropertiesofcolloids,.,scatteringoflight,Lightscatteringisaformofscatteringinwhichlightistheformofpropagatingenergywhichisscattered.Lightscatteringcanbethoughtofasthedeflectionofarayfromastraightpath,forexamplebyirregularitiesinthepropagationmedium,particles,orintheinterfacebetweentwomedia.,.,TheFaraday-TyndallEffect,Whenastrongbeamoflightispassedthroughacolloidalsol,avisiblecone,resultingfromthescatteringoflightbythecolloidalparticles,isformed.ThisistheFaraday-tyndalleffect.,.,Ultramicroscope,Anultramicroscopeisamicroscopewithasystemofilluminationthatallowsviewingoftinyparticles.Whenthediameterofaparticleisbelowornearthewavelengthofvisiblelight(around500nanometers),theparticlecannotbeseeninalightmicroscopewiththeusualmethodofillumination.Theultramicroscopesystemisbasedonlightscattering,notlightreflection.,.,Ultramicroscope,.,Electronmicroscope,Electronmicroscope,capableofyieldingpicturesoftheactualparticles,eventhoseapproachingmoleculardimensions,isnowwidelyusedtoobservethesize,shape,andstructureofcolloidalparticles.,.,.,Kineticpropertiesofcolloids,1,Thermallyinduced:Brownianmovement,diffusion,osmosis.2,gravitationallyinduced:sedimentation3,appliedexternally:viscosity,.,BrownianMotiontherandommovementofcolloidalpartocles,ThefirstsatisfactorytheoreticaltreatmentofBrownianmotionwasmadebyAlbertEinsteinin1905.,.,Diffusion,DeducedbyEinsteinandStrokesWhereNAisAvogadrosnumber,Risthegasconstant,isthecoefficientofviscosityofthesurroundingmedium,ristheradiusofthesphericalparticle,TistheabsolutetemperatureDiffusionisanentropyincreasingprocess.,.,Diffusion,.,Osmoticpressure,.,Sedimentation,Inagravitationalfield,heavyparticlessettletowardsthefootofacolumnofsolutionbytheprocesscalledsedimentation.Whenasolutionisallowedtostand,astateofequilibriumisfinallyreachedwhensedimentationanddiffusionbalanceeachother,thatis,wheninagivenintervaloftimetheamountofmaterialwhichfallsinthedownwarddirectionthroughaunitareaisthesameasthatwhichdiffusesupwardbecauseofthegreaterconcentrationatthelowerlevel.,sedimentation,diffusion,.,.,ultracentrifugation,Sedimentationisnormallyveryslow,butitcanbeacceleratedbyultracentrifugation,atechniquethatreplacesthegravitationalfieldwithacentrifugalfield.,WhereRisthegasconstant,Sisthesedimentationcoefficient,theunitSvedbergis1X10-13second,Tistheabsolutetemperature,Disthediffusionconstant,visthevolumeof1gofparticle,isthedensityofmedium.,.,supercentrifuge,.,Viscosity,Viscosityisenexpressionoftheresistancetoflowofasystemunderanappliedstress.Themoregreateristheappliedforcerequiredtomakeitflowataparticularrate.,.,ElectricalPropertiesofColloids,.,ElectrokineticPhenomena,ElectrophoresisElectroosmosisSedimentationpotentialStreamingpotential,.,Electrophoresis,.,Electroosmosis,.,Sedimentationpotential,.,Streamingpotential,.,StabilityofColloidSystems,KineticstabilitystableThermodinamicstabilityLyophobiccolloidsunstableLyophiliccolloidsstableAssociationcolloids,.,DLVOtheory,.,SensitizationandProtectiveColloidalAction,Thepresenceandmagnitude,orabsence,ofachargeonacolloidalparticleisanimportantfactorinthestabilityofcolloidalsystems.Sensitization:theadditionofasmallamountofhydrophilicorhydrophobiccolloidtoahydrophobiccolloidofoppositechargetendstosensitizeorevencoagulate.Protection:theadditionoflargeamountsofhydrophile,however,stabilizesthesystem,thehydrophilebeingadsorbedonthehydrophobicparticles.,.,Sensitizationprotection,.,Solubilization,Animportantpropertyofassociationcolloidsinthesolutionistheabilityofthemicellestoincreasethesolubilityofmaterialsthatarenormallyinsoluble,oronlyslightlysoluble,inthedispersionmediumused.,.,Thesurface-activeagent,iftakeninternallymustbe:1,nontoxic2,misciblewiththesolvent3,compatiblewiththematerialtobesolubilized4,freefromdisagreeableoderandtaster5,relativelynonvolatile,.,Associationcolloids,Drug,.,Solubilization,Factorsaffectingsolubilization1,thechemistryofthesurfactants2,thelocationofthedruginthemicells3,pH(nonionicsurfactants),.,.,.,.,Pharmaceuticalapplicationofcolloids,.,Pharmaceuticalapplicationofcolloids,Hydrogels,.,Hydrogels,.,Hydrogels,.,Hydrogels,.,Pharmaceuticalapplicationofcolloids,Microparticles1,carriersforvaccinesandanticancerdrugs2,reducingtheuptakeofthenanoparticlesbythecellsofthereticuloendothelialsystem3