基于離子濃差極化現(xiàn)象的分子富集機(jī)理及仿真分析-comsol 操作說明

1、10|PRECONCENTRATIONOFCHARGESPARTICLESINAMICRO-NANO-FLUIDICCHANNELModelingInstructionsFromtheFilemenu,chooseNew.NEWIntheNewwindow,clickModelWizard.MODELWIZARD1IntheModelWizardwindow,click2D.2IntheSelectPhysicstree,selectFluidFlowSingle-PhaseFlowCreepingFlow(spf).3ClickAdd.4IntheSelectPhysicstree,sele

2、ctAC/DCElectrostatics(es).5ClickAdd.6IntheSelectPhysicstree,selectChemicalSpeciesTransportTransportofDilutesSpecies(tds).7ClickAdd.8IntheConcentrationtable,enterthefollowingsetting:clIntheSelectPhysicstree,selectChemicalSpeciesTransportTransportofDilutesSpecies(tds).ClickAdd.IntheConcentrationtable,

3、enterthefollowingsetting:c2IntheSelectPhysicstree,selectChemicalSpeciesTransportTransportofDilutesSpecies(tds).ClickAdd.IntheConcentrationtable,enterthefollowingsetting:c3ClickStudy.IntheSelectStudytree,selectPresetStudiesforSelectedPhysicsInterfacesStationary.17ClickDone.GLOBALDEFINITIONSParameters

4、1OntheHometoolbar,clickParameters.IntheSettingswindowforParameters,locatetheParameterssection.Inthetable,enterthefollowingsetting:NameExpressionValueDescriptionW120um1.2E-4mLengthofmicrochannelH2um2E-6mWidthofmicrochannelsigma-5mC/m人2-0.005C/m2SurfacechargedensityphiO25.8mV0.0258VThermalvoltageVL202

5、0Voltageatinlet(inthermalvoltage)VR00Voltageatoutlet(inthermalvoltage)vcm00Cross-membraneVoltage(inthermalvoltage)T300K300KTemperaturerhole3kg/m人31000kg/m3Massdensityofwateretale-3Pa*s0.001PaDynamicViscositycO1mM1mol/m3ConcentrationofK+D11.97*le-9m人2/s1.97E-9m2/sDiffusioncoefficientofK+D22.03*le-9m人

6、2/s2.03E-9m2/sDiffusioncoefficientofCl-D30.51*le-9m人2/s5.10E-10m2/sDiffusioncoefficientofP2-rcO1e-71E-7RatioofparticleconcentrationinthereservoirtothatofCl-DEFINITIONSCreateanrandomfunctionforthesimulationofinitialconcentrationsofionsandparticles.1IntheHometoolbar,clickFunctionsLocalRandom.2IntheFun

7、ctionnametextfield,typeran.3IntheNumberofargumentstextfield,type2.4FromtheDistributionlist,chooseNormal.GEOMETRY11IntheModelBuilderwindow,underComponent1(comp1)clickGeometry1.IntheSettingswindowforGeometry,locatetheUnitssection.FromtheLengthunitlist,choosepm.LocatetheAdvancedsection.FromtheDefaultre

8、pairtolerancelist,chooseRelative.Rectangle1(r1)OntheGeometrytoolbar,clickPrimitivesandchooseRectangle.IntheSettingswindowforRectangle,locatetheSizeandShapesection.IntheWidthtextfield,type240.IntheHeighttextfield,typeH.LocatethePositionsection.Intheytextfield,type-2.Rectangle2(r2)OntheGeometrytoolbar

9、,clickPrimitivesandchooseRectangle.IntheSettingswindowforRectangle,locatetheSizeandShapesection.IntheWidthtextfield,type60.IntheHeighttextfield,type60.LocatethePositionsection.Intheytextfield,type-60.Rectangle3(r3)OntheGeometrytoolbar,clickPrimitivesandchooseRectangle.IntheSettingswindowforRectangle

10、,locatetheSizeandShapesection.IntheWidthtextfield,type60.IntheHeighttextfield,type60.10LocatethePositionsection.Inthextextfield,type180.11LocatethePositionsection.Intheytextfield,type-60.Point1(pt1)OntheGeometrytoolbar,clickPrimitivesandchoosePoint.IntheSettingswindowforPoint,locatethePointsection.I

11、nthextextfield,type119.Point2(pt2)OntheGeometrytoolbar,clickPrimitivesandchoosePoint.IntheSettingswindowforPoint,locatethePointsection.Inthextextfield,type121.Point3(pt3)OntheGeometrytoolbar,clickPrimitivesandchoosePoint.IntheSettingswindowforPoint,locatethePointsection.Inthextextfield,type119.Inthe

12、ytextfield,type-H.Point4(pt4)1OntheGeometrytoolbar,clickPrimitivesandchoosePoint.2IntheSettingswindowforPoint,locatethePointsection.3Inthextextfield,type121.Intheytextfield,type-H.FormUnion(fin)IntheModelBuilderwindow,underComponent1(comp1)Geometry1right-clickFormUnion(fin)andchooseBuildSelected.CRE

13、EPINGFLOW(SPF)1IntheModelBuilderwindow,underComponent1(comp1)clickCreepingFlow(spf).2IntheModelBuilderwindowstoolbar,clickShthoewbuttonandselectStabilizationinthemenu.3IntheSettingswindowforCreepingFlow,typeCreepingintheLabeltextfield.4ClicktoexpandtheConsistentStabilizationsection,thencleartheCross

14、winddiffusioncheckbox.CREEPING(SPF)TransportProperties11IntheModelBuilderwindow,expandtheComponent1(comp1)Creeping(spf)node,thenclickFluidProperties1.2IntheSettingswindowforFluidproperties,locatetheFluidPropertiessection.Fromtheplist,chooseUserdefined.Intheassociatedtextfield,typerho.Fromtheplist,ch

15、ooseUserdefined.Intheassociatedtextfield,typeeta.VolumeForce1OnthePhysicstoolbar,clickDomainsandchooseVolumeForce.IntheSettingswindowforVolumeForce,locatetheDomainSelectionsection.FromtheSelectionlistchooseAllDomains.LocatetheVolumeFheVolumeforcetable,enterthefollowingsetting:(cl-c2-2

16、*c3)*(es.Ex)*e_const*N_A_constx(cl-c2-2*c3)*(es.Ey)*econst*NAconstySymmetry1OnthePhysicstoolbar,clickBoundariesandchooseSymmetry.Selectboundaries5,9,11,13and18only.IntheSettingswindowforSymmetry,locatetheBoundarySelectionsection.ClicktheCreateSelectionbuttonandtypeCenterLineinthepop-upwindow.ClickOK

17、,thenCenterLineisshownundertheDefinitionsnodeintheModelBuilderwindow.Inlet11OnthePhysicstoolbar,clickBoundariesandchooseInlet.2Selectboundaries1and3only.3IntheSettingswindowforInlet,locatetheBoundaryConditionsection.Fromthelist,choosePressure.Outlet11OnthePhysicstoolbar,clickBoundariesandchooseOutle

18、t.Selectboundaries19and20only.3IntheSettingswindowforOutlet,locatethePressureConditionsection,selecttheNormalflowcheckbox.PressurePointConstraint11OnthePhysicstoolbar,clickPointsandchoosePressurePointConstraint.Selectpoint14only.ELECTROSTATICS(ES)1IntheModelBuilderwindow,underComponent1(comp1)clickE

19、lectrostatics(es).2IntheSettingswindowforElectrostatics,locateThicknesssection.IntheOut-of-planethicknesstextfield,type10um.ChargeConservation11IntheModelBuilderwindow,expandtheComponent1(comp1)Electrostatics(es)node,thenclickChargeConservation1.2IntheSettingswindowforChargeConservation,locatetheEle

20、ctricFieldsection.3FromtheRelativepermittivitylist,chooseUserdefined.Intheassociatedtextfield,type78.SpaceChargeDensity11OnthePhysicstoolbar,clickDomainsandchooseSpaceChargeDensity.2IntheSettingswindowforSpaceChargeDensity,locatetheDomainSelectionsection.FromtheSelectionlist,chooseAlldomains.3Locate

21、theSpaceChargeDensitysection.FromtheSpacechargedensitylist,chooseUserdefined.Intheassociatedtextfield,type(c1-c2-2*c3)*e_const*N_A_const.SurfaceChargeDensity11OnthePhysicstoolbar,clickBoundariesandchooseSurfaceChargeDensity.2Selectboundaries8and12only.3IntheSettingswindowforSurfaceChargeDensity,loca

22、tetheSurfaceChargeDensitysection.IntheSurfacechargedensitytextfield,typesigma.ElectricPotential11OnthePhysicstoolbar,clickBoundariesandchooseElectricPotential.2Selectboundaries1and3only.3IntheSettingswindowforElectricPotential,locatetheElectricPotentialsection.IntheElectricpotentialtextfield,typeVL*

23、phi0.ElectricPotential21OnthePhysicstoolbar,clickBoundariesandchooseElectricPotential.2Selectboundaries19and20only.3IntheSettingswindowforElectricPotential,locatetheElectricPotentialsection.IntheElectricpotentialtextfield,typeVR*phi0.ElectricPotential31OnthePhysicstoolbar,clickBoundariesandchooseEle

24、ctricPotential.2Selectboundary10only.3IntheSettingswindowforElectricPotential,locatetheElectricPotentialsection.IntheElectricpotentialtextfield,type(VL+VR)/2-vcm)*phi0.TRANSPORTOFDILUTEDSPECIES(TDS)IntheModelBuilderwindow,underComponent1(comp1)clickTransportofDilutedSpecies(tds).2IntheSettingswindow

25、forTransportofDilutedSpecies,typec1SpeciesintheLabeltextfield.3LocatetheTransportMechanismsection.SelecttheMigrationinelectricfieldcheckbox.4ClicktoexpandtheConsistentStabilizationsection,thencleartheCrosswinddiffusioncheckbox.5ClicktoexpandtheAdvancedSettingssection.FromtheConvectivetermlist,choose

26、Conservativeform.6ClicktoexpandtheDiscretizationsection.FromtheConcentrationlist,chooseQuadratic.C1SPECIES(TDS)TransportProperties11IntheModelBuilderwindow,expandtheComponent1(comp1)c1Species(tds)node,thenclickTransportProperties1.2IntheSettingswindowforTransportProperties,locatetheModelInputssectio

27、n.FromtheVelocityfieldlist,chooseVelocityfield(spf).FromtheElectricpotentiallist,chooseElectricpotential(es).IntheTemperaturetextfield,typeT.3LocatetheDiffusionsection.IntheDiffusioncoefficienttextfield,typeD1.4LocatetheMigrationinElectricFieldsection.IntheChargenumbertextfield,type1.InitialValues1I

28、ntheModelBuilderwindow,clickComponent1(comp1)c1Species(tds)InitialValues1.2IntheSettingswindowforInitialValues,locatetheInitialValuessection.IntheConcentrationtextfield,typec0*(1+0.0001*ran(x1/m,y1/m).Inflow11OnthePhysicstoolbar,clickBoundariesandchooseInflow.2Selectboundaries1and3only.3IntheSetting

29、swindowforInflow,locatetheConcentrationsection.Typec0inthetextfield.Outflow11OnthePhysicstoolbar,clickBoundariesandchooseOutflow.2Selectboundaries19and20only.Symmetry11OnthePhysicstoolbar,clickBoundariesandchooseSymmetry.2IntheSettingswindowforSymmetry,locatetheBoundarySelectionsection.FromtheSelect

30、ionlist,chooseCenterLine.Concentration11OnthePhysicstoolbar,clickBoundariesandchooseConcentration.2Selectboundaries10only.3IntheSettingswindowforConcentration,locatetheConcentrationsection,selecttheSpeciesc1checkboxandtypec0*2intheassociatedtextfield.TRANSPORTOFDILUTEDSPECIES2(TDS2)1IntheModelBuilde

31、rwindow,underComponent1(comp1)clickTransportofDilutedSpecies2(tds2).2IntheSettingswindowforTransportofDilutedSpecies,typec2SpeciesintheLabeltextfield.3LocatetheTransportMechanismsection.SelecttheMigrationinelectricfieldcheckbox.4ClicktoexpandtheConsistentStabilizationsection,thencleartheCrosswinddif

32、fusioncheckbox.5ClicktoexpandtheAdvancedSettingssection.FromtheConvectivetermlist,chooseConservativeform.6ClicktoexpandtheDiscretizationsection.FromtheConcentrationlist,chooseQuadratic.C2SPECIES(TDS2)TransportProperties11IntheModelBuilderwindow,expandtheComponent1(comp1)c2Species(tds2)node,thenclick

33、TransportProperties1.2IntheSettingswindowforTransportProperties,locatetheModelInputssection.FromtheVelocityfieldlist,chooseVelocityfield(spf).FromtheElectricpotentiallist,chooseElectricpotential(es).IntheTemperaturetextfield,typeT.3LocatetheDiffusionsection.IntheDiffusioncoefficienttextfield,typeD2.

34、4LocatetheMigrationinElectricFieldsection.IntheChargenumbertextfield,type-1.InitialValues11IntheModelBuilderwindow,clickComponent1(comp1)c2Species(tds2)InitialValues1.2IntheSettingswindowforInitialValues,locatetheInitialValuessection.IntheConcentrationtextfield,typec0*(1-2*rc0).Inflow11OnthePhysicst

35、oolbar,clickBoundariesandchooseInflow.2Selectboundaries1and3only.IntheSettingswindowforInflow,locatetheConcentrationsection.Typec0*(1-2*rc0)inthetextfield.Outflow11OnthePhysicstoolbar,clickBoundariesandchooseOutflow.2Selectboundaries19and20only.Symmetry11OnthePhysicstoolbar,clickBoundariesandchooseS

36、ymmetry.2IntheSettingswindowforSymmetry,locatetheBoundarySelectionsection.FromtheSelectionlist,chooseCenterLine.TRANSPORTOFDILUTEDSPECIES3(TDS3)1IntheModelBuilderwindow,underComponent1(comp1)clickTransportofDilutedSpecies3(tds3).2IntheSettingswindowforTransportofDilutedSpecies,typec3SpeciesintheLabe

37、ltextfield.3LocatetheTransportMechanismsection.SelecttheMigrationinelectricfieldcheckbox.4ClicktoexpandtheConsistentStabilizationsection,thencleartheCrosswinddiffusioncheckbox.5ClicktoexpandtheAdvancedSettingssection.FromtheConvectivetermlist,chooseConservativeform.6ClicktoexpandtheDiscretizationsec

38、tion.FromtheConcentrationlist,chooseQuadratic.C3SPECIES(TDS3)TransportProperties11IntheModelBuilderwindow,expandtheComponent1(comp1)c3Species(tds3)node,thenclickTransportProperties1.2IntheSettingswindowforTransportProperties,locatetheModelInputsection.FromtheVelocityfieldlist,chooseVelocityfield(spf

39、).FromtheElectricpotentiallist,chooseElectricpotential(es).IntheTemperaturetextfield,typeT.3LocatetheDiffusionsection.IntheDiffusioncoefficienttextfield,typeD3.4LocatetheMigrationinElectricFieldsection.IntheChargenumbertextfield,type-2.InitialValues11IntheModelBuilderwindow,clickComponent1(comp1)c3S

40、pecies(tds3)InitialValues1.2IntheSettingswindowforInitialValues,locatetheInitialValuessection.IntheConcentrationtextfield,typec0*rc0.Inflow11OnthePhysicstoolbar,clickBoundariesandchooseInflow.2Selectboundaries1and3only.IntheSettingswindowforInflow,locatetheConcentrationsection.Typec0*rc0inthetextfie

41、ld.Outflow11OnthePhysicstoolbar,clickBoundariesandchooseOutflow.2Selectboundaries19and20only.Symmetry11OnthePhysicstoolbar,clickBoundariesandchooseSymmetry.2IntheSettingswindowforSymmetry,locatetheBoundarySelectionsection.FromtheSelectionlist,chooseCenterLine.MESH1IntheModelBuilderwindow,underCompon

42、ent1(comp1)right-clickMesh1andchooseMoreOperationsEdge.Edge11IntheSettingswindowforEdge,locatetheBoundarySelectionsection.ClickthePasteSelectionbutton,andtype2,4-5,8-13,15,17-18inthetextfieldofthepop-upwindow.2IntheModelBuilderwindow,underComponent1(comp1)Mesh1right-clickEdge1andchooseDistribution.D

43、istribution11SelectBoundaries8,9,12and13only.2IntheSettingswindowforDistribution,locatetheDistributionsection.3FromtheDistributionpropertieslist,choosePredefineddistributiontype.4IntheNumberofelementstextfield,type300.5IntheElementratiotextfield,type300.6FromtheDistributionmethod,choosetheGeometrics

44、equence.7SelecttheSymmetricdistributioncheckbox.Edge1IntheModelBuilderwindow,underComponent1(comp1)Mesh1right-clickEdge1andchooseDistribution.Distribution21SelectBoundaries10and11only.2IntheSettingswindowforDistribution,locatetheDistributionsection.3FromtheDistributionpropertieslist,choosePredefined

45、distributiontype.4IntheNumberofelementstextfield,type60.5IntheElementratiotextfield,type30.6FromtheDistributionmethod,choosetheGeometricsequence.7SelecttheSymmetricdistributioncheckbox.Edge1IntheModelBuilderwindow,underComponent1(comp1)Mesh1right-clickEdge1andchooseDistribution.Distribution31SelectB

46、oundaries15,17and18only.2IntheSettingswindowforDistribution,locatetheDistributionsection.3FromtheDistributionpropertieslist,choosePredefineddistributiontype.4IntheNumberofelementstextfield,type80.5IntheElementratiotextfield,type2000.6FromtheDistributionmethod,choosetheGeometricsequence.7SelecttheRev

47、ersedistributioncheckbox.Edge1IntheModelBuilderwindow,underComponent1(comp1)Mesh1right-clickEdge1andchooseDistribution.Distribution41SelectBoundaries2,4and5only.2IntheSettingswindowforDistribution,locatetheDistributionsection.3FromtheDistributionpropertieslist,choosePredefineddistributiontype.4Inthe

48、Numberofelementstextfield,type80.5IntheElementratiotextfield,type2000.6FromtheDistributionmethod,choosetheGeometricsequence.Mapped11IntheModelBuilderwindow,underComponent1(comp1)right-clickMesh1andchooseMapped.2IntheSettingswindowforMapped,LocatetheDomainSelectionsection.FromtheGeometricentitylevell

49、ist,chooseDomain.3Selectdomains2,3and5only.4IntheModelBuilderwindow,underComponent1(comp1)Mesh1right-clickMapped1andchooseDistribution.Distribution11Selectboundaries3,7,16and20only.2IntheSettingswindowforDistribution,locatetheDistributionsection.3FromtheDistributionpropertieslist,choosePredefineddis

50、tributiontype.4IntheNumberofelementstextfield,type40.5IntheElementratiotextfield,type12000.6FromtheDistributionmethod,choosetheGeometricsequence.Mapped21IntheModelBuilderwindow,underComponent1(comp1)right-clickMesh1andchooseMapped.2IntheSettingswindowforMapped,LocatetheDomainSelectionsection.Fromthe

51、Geometricentitylevellist,chooseDomain.3Selectdomains1and4only.4IntheModelBuilderwindow,underComponent1(comp1)Mesh1right-clickMapped2andchooseDistribution.Distribution11Selectboundaries1,6,14and19only.2IntheSettingswindowforDistribution,locatetheDistributionsection.3FromtheDistributionpropertieslist,

52、choosePredefineddistributiontype.4IntheNumberofelementstextfield,type40.IntheElementratiotextfield,type1200000.6FromtheDistributionmethod,choosetheGeometricsequence.7SelecttheReversedistributioncheckbox.8ClickBuildAll.STUDY11IntheModelBuilderwindow,underComponent1(comp1)clickStudy1.IntheSettingswind

53、owforstudy,typeStudy1(referenceinitial)intheLabeltextfield.3LocatetheStudySettingsection,cleartheGeneratedefaultplotscheckbox.Step1:Stationary1IntheModelBuilderwindow,underStudy1clickStep1:Stationary.2IntheSettingswindowforStationary,clicktoexpandtheStudyextensionssection.3LocatetheStudyExtensionsse

54、ction.SelecttheAuxiliarysweepcheckbox.ClicktheAdd.Inthetable,enterthefollowingsettings:ParameternameParametervaluelistParameterunitvcm(Cross-membraneVoltage(inthermalvoltage)26OntheStudytoolbar,clickCompute.ADDSTUDY1OntheHometoolbar,clickAddStudytoopentheAddStudywindow.2GototheAddStudywindow.3Findth

55、eStudiessubsection.IntheSelectStudytree,selectPresetStudiesStationary.ClickAddStudyinthewindowtoolbar.OntheHometoolbar,clickAddStudyagaintoclosetheAddStudywindow.STUDY21IntheModelBuilderwindow,underComponent1(comp1)clickStudy2.IntheSettingswindowforstudy,typeStudy2(changingvcm)intheLabeltextfield.3L

56、ocatetheStudySettingsection,cleartheGeneratedefaultplotscheckbox.Step1:Stationary1.IntheModelBuilderwindow,underStudy1clickStep1:Stationary.2.IntheSettingswindowforStationary,locatetheValuesofDependentVariablessection.3.FindtheInitialvaluesofvariablessolvedforsubsection.FromtheSettingslist,chooseUse

57、rcontrolled.4.FromtheMethodlist,chooseSolution.5.FromtheStudylist,chooseStudy1(referenceinitial),Stationary.6.FromtheParametervalue(vcm)list,choose2.7.FindtheValuesofvariablesnotsolvedforsubsection.FromtheSettingslist,chooseUsercontrolled.8.FromtheMethodlist,chooseSolution.9.FromtheStudylist,chooseS

58、tudy1(referenceinitial),Stationary.10.FromtheParametervalue(vcm)list,choose2.11.LocatetheStudyExtensionssection.12.SelecttheAuxiliarysweepcheckbox.13.ClicktheAdd.14.Inthetable,enterthefollowingsettings:ParameternameParametervaluelistParameterunitvcm(Cross-membraneVoltage(inthermalvoltage)range(2,1,5

59、0)15.FromtheRuncontinuationforlist,chooseNoparameter.16.FromtheReusesolutionfromprevioussteplist,chooseYes.17.OntheStudytoolbar,clickCompute.RESULTS1DPlotGroup1(Fig.4)1.OntheHometoolbar,clickAddPlotGroupandchoose1DPlotGroup.2.IntheSettingswindowfor1DPlotGroup,typeEnrichmentfactorintheLabeltextfield.

60、3.LocatetheDatasection.FromtheDatasetlist,chooseStudy2(changingvcm)/Solution2(sol2).4.FromtheParameterselection(vcm)list,chooseFromlist.5.FromtheParametervalues(vcm)list,choose4,10,14,17,20,23,26,34and50.6LocatethePlotSettingssection.Selectthex-axislabelcheckboxandtypex(pm)intheassociatedtextfield.L