物理药剂学ppt课件

Colloidaldispersionsystem,1,Classificationofdispersedsystembasedonparticlesize,2,TypesofColloidaldispersion,3,Lyophiliccolloids,Systemscontainingcolloidalparticlesthatinteracttoanappreiableextentwiththedispersionmediumarereferredtoaslyophilic(solvent-loving)colloids.hydrophilicsols:gelatin,acacia,insulin,albuminLipophiliccolloids:rubber,polystyrene.Amaterialthatformsalyophiliccolloidalsysteminoneliquid(e.g.water)maynotdosoinanotherliquid(e.g.benzene).,4,5,6,Lyophobiccolloids,Lyophobiccolloidsiscomposedofmaterialsthathavelittleattraction.e.g.gold,silver,sulfur,arsenoussulfide,andsilveriodide.,7,Themethodstopreparelyophobiccolloids,Dispersionmethods1,grindingmethod2,sonicationdispersionmethod3,arcdischargemethodCondensationmethods1,physicalmethods2,chemicalmethods,8,grindingmethod,9,sonicationdispersionmethod,10,arcdischargemethod,Owingtotheintenseheatgeneratedbythearc,someofthemetaloftheelectrodesisdispersedasvapor,whichcondensestoformcolloidalparticles.,11,Physicalcondensationmethods,1,replacementofsolvent,12,Physicalcondensationmethods,2,Steamquenchmethod,13,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,14,Solpurification,1,dialysismethod2,ultrafiltration,15,dialysismethod,Semipermeablemembrane,16,dialysismethod,Electrodialysis,17,ultrafiltration,Semipermeablemembrane,18,ultrafiltration,Electroultrafiltration,19,Associationcolloids,20,CMC,thecriticalmicelleconcentration(CMC)isdefinedastheconcentrationofsurfactantsabovewhichmicellesformandalladditionalsurfactantsaddedtothesystemgotomicelles.,21,Typeofmicelle,CylindricalmicelleBilayerBilayervesicleInvertedmicelleMicrotubule,22,Classificationandtypicalexamplesofassociationcolloids,23,Propertiesofsurface-activeagentsshowingchangesthatoccursharplyattheCMC,24,PredicttheCMCofthemixture,1=11+22,Todeterminetheminimumamountofsurfactant,25,Opticalpropertiesofcolloids,26,scatteringoflight,Lightscatteringisaformofscatteringinwhichlightistheformofpropagatingenergywhichisscattered.Lightscatteringcanbethoughtofasthedeflectionofarayfromastraightpath,forexamplebyirregularitiesinthepropagationmedium,particles,orintheinterfacebetweentwomedia.,27,TheFaraday-TyndallEffect,Whenastrongbeamoflightispassedthroughacolloidalsol,avisiblecone,resultingfromthescatteringoflightbythecolloidalparticles,isformed.ThisistheFaraday-tyndalleffect.,28,Ultramicroscope,Anultramicroscopeisamicroscopewithasystemofilluminationthatallowsviewingoftinyparticles.Whenthediameterofaparticleisbelowornearthewavelengthofvisiblelight(around500nanometers),theparticlecannotbeseeninalightmicroscopewiththeusualmethodofillumination.Theultramicroscopesystemisbasedonlightscattering,notlightreflection.,29,Ultramicroscope,30,Electronmicroscope,Electronmicroscope,capableofyieldingpicturesoftheactualparticles,eventhoseapproachingmoleculardimensions,isnowwidelyusedtoobservethesize,shape,andstructureofcolloidalparticles.,31,32,Kineticpropertiesofcolloids,1,Thermallyinduced:Brownianmovement,diffusion,osmosis.2,gravitationallyinduced:sedimentation3,appliedexternally:viscosity,33,BrownianMotiontherandommovementofcolloidalpartocles,ThefirstsatisfactorytheoreticaltreatmentofBrownianmotionwasmadebyAlbertEinsteinin1905.,34,Diffusion,DeducedbyEinsteinandStrokesWhereNAisAvogadrosnumber,Risthegasconstant,isthecoefficientofviscosityofthesurroundingmedium,ristheradiusofthesphericalparticle,TistheabsolutetemperatureDiffusionisanentropyincreasingprocess.,35,Diffusion,36,Osmoticpressure,=cRT,=cgRT,cg=,cg=(1+cg),37,Sedimentation,Inagravitationalfield,heavyparticlessettletowardsthefootofacolumnofsolutionbytheprocesscalledsedimentation.Whenasolutionisallowedtostand,astateofequilibriumisfinallyreachedwhensedimentationanddiffusionbalanceeachother,thatis,wheninagivenintervaloftimetheamountofmaterialwhichfallsinthedownwarddirectionthroughaunitareaisthesameasthatwhichdiffusesupwardbecauseofthegreaterconcentrationatthelowerlevel.,sedimentation,diffusion,38,39,ultracentrifugation,Sedimentationisnormallyveryslow,butitcanbeacceleratedbyultracentrifugation,atechniquethatreplacesthegravitationalfieldwithacentrifugalfield.,WhereRisthegasconstant,Sisthesedimentationcoefficient,theunitSvedbergis1X10-13second,Tistheabsolutetemperature,Disthediffusionconstant,visthevolumeof1gofparticle,isthedensityofmedium.,40,supercentrifuge,41,Viscosity,Viscosityisenexpressionoftheresistancetoflowofasystemunderanappliedstress.Themoregreateristheappliedforcerequiredtomakeitflowataparticularrate.,42,ElectricalPropertiesofColloids,43,ElectrokineticPhenomena,ElectrophoresisElectroosmosisSedimentationpotentialStreamingpotential,44,Electrophoresis,45,Electroosmosis,46,Sedimentationpotential,47,Streamingpotential,48,StabilityofColloidSystems,KineticstabilitystableThermodinamicstabilityLyophobiccolloidsunstableLyophiliccolloidsstableAssociationcolloids,49,DLVOtheory,50,SensitizationandProtectiveColloidalAction,Thepresenceandmagnitude,orabsence,ofachargeonacolloidalparticleisanimportantfactorinthestabilityofcolloidalsystems.Sensitization:theadditionofasmallamountofhydrophilicorhydrophobiccolloidtoahydrophobiccolloidofoppositechargetendstosensitizeorevencoagulate.Protection:theadditionoflargeamountsofhydrophile,however,stabilizesthesystem,thehydrophilebeingadsorbedonthehydrophobicparticles.,51,Sensitizationprotection,52,Solubilization,Animportantpropertyofassociationcolloidsinthesolutionistheabilityofthemicellestoincreasethesolubilityofmaterialsthatarenormallyinsoluble,oronlyslightlysoluble,inthedispersionmediumused.,53,Thesurface-activeagent,iftakeninternallymustbe:1,nontoxic2,misciblewiththesolvent3,compatiblewiththematerialtobesolubilized4,freefromdisagreeableoderandtaster5,relativelynonvolatile,54,Associationcolloids,Drug,55,Solubilization,Factorsaffectingsolubilization1,thechemistryofthesurfactants2,thelocationofthedruginthemicells3,pH(nonionicsurfactants),56,57,58,59,Pharmaceuticalapplicationofcolloids,60,Pharmaceuticalapplicationofcolloids,Hydrogels,61,Hydrogels,62,Hydrogels,63,Hydrogels,64,Pharmaceuticalapplicationofcolloids,Microparticles1,carriersforvaccinesandanticancerdrugs2,reducingtheuptakeofthenanoparticlesbythecellsofthereticuloendothelialsystem3,en