简介:Viaseveraltechniquestomodifysensitivematrixforinhabitingtheleakageoffluorescentindicator,anewstablesensingmaterialformonitoringphosphateshasbeenpreparedandappliedtothemeasurementofphosphatesinartificialseawater.ItisbasedonthereactionofPO3-4withAl(Ⅲ)-Morinthatleadstothefluorescencequenchingofthecompositematrix.AtpHvalue4.0andthesalinityvalue25.0,theresponsetimeofoutputsignalhavingreachedthesteadystateislessthan300seconds.ItscalibrationgraphisgainedintherangeofH2PO-4massconcentrationfrom1.50to7.00μg/mLwiththelimitofdetection(3σ/K)0.02μg/mL.Whenitwasusedtomeasurephosphatesinartificialseawater,therecoveryrangedfrom96.78%to102.09%.Beingstoredunderthepropercondition,themembranesmaintainsensitivefor90-120days,andareabletobeusedfor50-80timeswithindicatorsupplement.
简介:Montmorillonite(MMT)wasdirectlymodifiedwithhexadecyltrimethylammoniumbromide.Theinterlayerspacingoftheorganophilicmontmorillonite(organo-MMT)correspondingtothed(001)planepeakwas2.21nm.Theinfluencesofthecontentoforgano-MMTandmixingconditionsincludingmixingtemperatureandmixingtimeontheintercalationandexfoliationstructuresofMMT/epoxyresincompositeswereinvestigatedbywideX-raydiffraction(WXRD).TheX-raypatternsrevealthatorgano-MMTwasintercalatedbytheepoxyresinduringmixingprocess.Onlyundercertainmixingconditions,couldtheexfoliationnanocompositesbeformed.Themechanicalandthermalpropertiesofthecompositesweremeasured.TheresultsindicatethatthecompositeshavebettermechanicalpropertiesandhigherTgthanthoseofthepristineepoxyresin.
简介:Graphenenanosheets(GS)wereeasilypreparedthroughliquid-phaseexfoliationofgraphitepowderinN,N-dimethylformamide(DMF)withtheassistanceofsodiumcitrate.Then,GSwascoatedontoaglassycarbonelectrode(GCE)surfacebydroptofabricateaGS/GCEnanointerface.Subsequently,byusingtetraethylorthosilicatesolasprecursor,nanosilicawaselectrochemicallydepositedontotheGS/GCEsurfacetoproduceananocompositefilmelectrode(nanosilica/GS/GCE).Electrochemicalbehaviorsofmethylparathion(MP)onthenanosilica/GS/GCEsurfacewereinvestigatedthoroughly.Itwasfoundthatthenanosilica/GSnanocompositescanimprovetheredoxpeakcurrentsofMPsignificantlyduetothesynergeticeffect.TheoxidationpeakcurrentwaslinearlyrelatedtoMPconcentrationintherangefrom0.0005mmol/Lto5.6mmol/L.Thedetectionlimitwascalculatedtobe0.07nmol/L(S/N=3).ThedevelopedmethodwasusedtodetermineMPinrealsamples.Therecoverieswereintherangefrom95.4%to104.2%,demonstratingsatisfactoryresults.
简介:Fe2O3solwiththeparticlediameterof3-5nmwasflocculatedbytheadditionofSDS,andtheflocculateformedwasredispersedbythefurtheradditionofthatsurfactant.ThusthesurfactantbilayerwasformedonthesurfaceofFe2O3.Theemulsionpolymerizationofstyrene(St)adsolubilizedonthesurfactantadsorbedbilayerwascarriedoutbyinitiatorpotassiumpersulfate(KPS).TheUV-Visandsurfacephotovoltagespectra(SPS)indicatethattheFe2O3particleswereencapsulatedinpolystyrene(PSt)successfully.
简介:有核心壳的合成nanoparticles组织的Cross-linked-cyclodextrinpolymer/Fe3O4在carboxymethyl-cyclodextrin的表面上经由生气连接反应被准备(厘米--CD)在-cyclodextrin的修改Fe3O4nanoparticles由把epichlorohydrin用作crosslinking的碱的答案代理人。准备合成nanoparticles的形态学,结构和磁性被传播电子显微镜学(TEM)调查,Fourier变换红外线(FTIR)spectrometry,X光检查衍射(XRD)测量,thermogravimetric分析(TGA)和颤动的样品magnetometry(VSM)分别地。
简介:Toexaminetheeffectivenessofirondust-zeolitecompositeasanadsorbentfortheremovalofheavymetalionsfromaqueoussolutions,theadsorptionisotherms,thekinetic,thermodynamicandoptimumconditions,suchasinitialconcentration,pH,contacttime,adsorbentdosageandcompetitiveadsorptionconditionsofheavymetalswereinvestigated.ThecharacterizationofthecompositewascharacterizedviaFTIR,SEM,XRFandXRDmethods.Kineticresultsontheremovalofheavymetalionsfromaqueoussolutionshavebeenwelldescribedbythepseudo-second-ordermodel.TheadsorptiondataforCdandNiionswerefittedwellwiththeLangmuirandFretm-dlichisothermmodels,respectively.Themaximumadsorptioncapacitiesofirondust-zeoliteforCdandNiionswereequalto78.125and76.33mg/g,respectively.Thethermodynamicparameterssuchasenthalpy,entropyandfreeenergyofadsorptionofmetalionsweredetermined.Itwasfoundthattheprocessisendothermic,favorableandspontaneous.ThecompetitiveadsorptionabilityofheavymetalionsinthebinarysystemonthecompositeshowedthatCdionshadasynergisticeffectontheadsorotionofNiandNiionshadthenegativeeffectonCdadsorption.