Simulation-for-the-Self-Assembly-of-Polymer-Blends-With-Nano-scaled-Features.pdf

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1、NumericalSimulationfortheSelf-assemblyofPolymerBlendswithNano-scaledFeaturesBYYINGRUISHANGDISSERTATIONSUBMITTEDTOTHEFACULTYOFTHEDEPARTMENTOFPLASTICSENGINEERINGINPARTIALFULFILLMENTOFTHEREQUIREMENTSFORTHEDEGREEOFDOCTOROFPHILOSOPHYPLASTICSENGINEERINGUNI

2、VERSITYOFMASSACHUSETTSLOWELL2008DissertationSupervisor:DavidO.Kazmer,Ph.D.Professor,DepartmentofPlasticsEngineeringiicCopyrightbyYingruiShangAllRightsReservediiiIcertifythatIhavereadthisdissertationandthatinmyopinionitisfullyadequate,inscopeandquali

3、ty,asadissertationforthedegreeofDoctorofPhilosophy.DavidO.Kazmer(PrincipleAdvisor)IcertifythatIhavereadthisdissertationandthatinmyopinionitisfullyadequate,inscopeandquality,asadissertationforthedegreeofDoctorofPhilosophy.CarolBarryIcertifythatIhavere

4、adthisdissertationandthatinmyopinionitisfullyadequate,inscopeandquality,asadissertationforthedegreeofDoctorofPhilosophy.JoeyMeadivAbstractThephaseseparationofpolymerblendsisnumericallymodeled.Thefreeenergyprofileoftheblendsinthediffusioncontrolledproce

5、ssisdescribedbytheCahn-Hilliardequation,whichiscomposedwiththelocalfreeenergyandthegradientenergycoefficient.TheFlory-Hugginsequationisusedforthelocalfreeenergyoftheblends.Thegradientenergycoefficient,κ,determinesthecontributionofthegradienttothetotalfre

6、eenergy.Thephaseseparationofbinaryandternaryblendsisstudiednumerically.Themechanismsoftheevolutionofthephaseseparationareinvestigated.Itisobserved1thatthecharacteristiclength,R,isproportionaltot3,wheretisthetime.Inthesituationwhenastrippatternedsubst

7、rateispresent,thecharacteristiclengthoftheinterfaceofthepolymerandsubstrateisconfinedbythecharacteristiclengthonthepatterninthedirectionperpendiculartothestrip.Thecompositionprofileofthephaseseparationinthelateraldirectionofthefilmisalsoinvestigated.The

8、self-assemblyofapolymer-polymer-solventternarysystemonaheteroge-neouslyfunctionalizedsubstratewasinvestigatedina3-dimensionalnumericalmodel.Thenumericalresultsareverifiedwiththeexperimentresult.TheexperimentsareconductedinasystemofPS/PAAinDMFsolution.