简介：Ourrecentstudiesconcerningthebindingofionicsurfactantsonoppositelychargedpolyelectrolytesobservedwithfluorescencetechniquesarereviewed.Thecationicsurfactantscetyltrimethylammoniumbromide(CTAB),dodecyltrimethylammoniumchloride(DTAC),andnonionicsurfactantoctaethyleneglycolmonododecylether(C12E8)wereallowedtobindonanionicpoly(2-acrylamido-2-methylpropanesulfonicacid)(PAMPS)anditspyreneand/ornaphthalenelabeledcopolymers.TherelativeexcimeremissionintensityIE/IMofacationicprobe1-pyrenemethylaminehydrochloridewerechosentomonitorthebindingprocessandtheconformationchangeofsurfactant-boundpolyelectrolytes.The1:1aggregationofpolyelectrolyte-CTABwithrespecttothechargewasfoundaslongastheCTABconcentrationwasslightlyhigherthanitscriticalaggregationconcentration(CAC).TheintermolecularNRETindicatedthattheCTAB-boundpolyelectrolytesaggregatedtogetherthroughthehydrophobicinteractionbetweentheCTABtails.However,neither1:1polyelectrolyte-DTACaggregationnorintermolecularaggregationofDTAC-boundpolyelectrolytewasobservedowingtoitsweakerhydrophobicityof12carbonatomsinthetail,whichisshorterthanthatofCTAB.Asknownfromthefluorescenceresults,nonionicsurfactantC12E8didnotbindontheanionicpolyelectrolytes,butthepresenceofPAMPSpromotedthemicelleformationforC12E8attheCACslightlybelowitscriticalmicelleconcentration(CMC).ThesolidcomplexofdansyllabeledAMPScopolymer-surfactantexhibitedadecreaseinlocalpolaritywithincreasingchargedensityofthepolyelectrolyteorwithalkanetaillengthofthesurfactant.SAXSsuggestedalamellastructurefortheAMPScopolymersurfactantsolidcomplexeswithalongperiodof3.87nmforCTABand3.04nmforDTAC,respectively.

简介：Twograftingmethods,i.e.solutiongraftingandpre-adsorbing,areintroducedtocovalentlyimmobilizehydrophilicpolymersonsegmentedpolyurethane(SPU)tomodifyitshydrophilicityandtoimproveitscellcompatibility.Solutiongraftingresultsinhigherdegreeofgraftingandroughersurfacemorphology.Cellcultureevaluationdemonstratesthatthemodifiedmembranesthusobtainedaredisadvantageoustotheendothelialcell(ECs)growthprobablybecausethehydrophilicgroupsonthesurfaceareover-crowded.However,pre-absorbinggraftinggenerateslowerdegreeofgrafting,whichisdetectedandconfirmedbyATR-FTIRspectraandwatercontactangle.Scanningelectronmicroscopic(SEM)measurementshowsthatthelattermethodproducesaplaneandsmoothmorphology,whichissimilartotheSPUcontrolsamplecontrolled.Whengraftingwithlowermonomerconcentration,ECscouldgrowonSPU-g-PHEA[poly(2-hydroxyethylacrylate)],SPU-g-PAAm(polyacrylamide),SPU-g-PDMA[poly(2-(dimethylamino)ethylmethacrylate)]orquaternizedSPU-g-PDMAsurfacewithelongatedcellshapes.Hence,thecellcompatibilityofSPUisimprovedandausefulmethodtoconstructacellcompatiblelayeronthepolymersurfacehasbeendeveloped.``

简介：Inthiswork,somechemometricsmethodsareappliedforthemodelingandpredictionoftheHildebrandsolubilityparameterofsomepolymers.Ageneticalgorithm(GA)methodisdesignedfortheselectionofvariablestoconstructtwomodelsusingthemultiplelinearregression(MLR)andleastsquare-supportvectormachine(LS-SVM)methodsinordertopredicttheHildebrandsolubilityparameter.TheMLRmethodisusedtobuildalinearrelationshipbetweenthemoleculardescriptorsandtheHildebrandsolubilityparameterforthesecompounds.ThentheLS-SVMmethodisutilizedtoconstructthenon-linearquantitativestructure-activityrelationship(QSAR)models.TheresultsobtainedusingtheLS-SVMmethodarethencomparedwiththoseobtainedfortheMLRmethod;itwasrevealedthattheLS-SVMmodelwasmuchbetterthantheMLRone.Theroot-mean-squareerrorsofthetrainingsetandthetestsetfortheLS-SVMmodelwere0.2912and0.2427,andthecorrelationcoefficientswere0.9662and0.9518,respectively.ThispaperprovidesanewandeffectivemethodforpredictingtheHildebrandsolubilityparameterforsomepolymers,andalsorevealsthattheLS-SVMmethodcanbeusedasapowerfulchemometricstoolforthequantitativestructure-propertyrelationship(QSPR)studies.