0.6

0.65

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0.75

0.8

0.85

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0.95

1

1.05

1.1

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

d/d 0

ΦCyclic

Series1Series2Series3

4

4.5

5

5.5

6

6.5

7

7.5

8

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

DomainSpacing

ΦCyclic

LinearN=12andCyclicN=24atDifferentχ Values

Series1Series2

PureLinear

1. M.W.Matsen,Macromolecules,2012.2. M.G.Buonomenna,et.al.RSCAdv.,2012.3.C.M.Bates,et.al.,Macromolecules,2013.4.C.Tang,C.J.Hawker,et.al.Science, 2008.

5.R.D.GrootandP.B.Warren,J.Chem.Phys., 1997

The Effect of Additive Cyclic Blends on Linear Block Copolymer Domain Spacing Maxwell Rick1, Jessie Troxler2, Amy D. Goodson2, Julie N. L. Albert2, and Henry S. Ashbaugh21Benjamin Franklin High School, 2Tulane University

Abstract

AcknowledgementsThankyoutotheAlbertGroupandtheAshbaughGroupWethanktheNationalScienceFoundationforfinancialsupportthroughgrantsDMR-1460637andIIA-1430280,andtheGraduateResearchFellowshipProgram(ADG).

ConclusionsandFutureWork• Blendingcyclicblockcopolymersintotheirlinearanaloguesreducesdomain

spacinglinearly.• Blendingorderedcyclicblockcopolymersintodisorderedlinearblock

copolymerscanresultinorderedsystems.Thisrepresentsawaytoreducedomainspacing,aslowerχ valuesandchainlengthscorrespondtolowerdomainspacingbutmaybebelowtheODT.

• Moresimulationsofdifferentχ valuesandchainlengthswillbecarriedouttofurthertesttheeffectivenessofcyclic-linearblendstoinduceorder.

• Ultimately,thinfilmsimulationsarenecessary,asnanolithographyusesthinfilms(thesesimulationsareinthebulk,butshouldnothavecrucialdifferencestothinfilmsimulations).Cylindersimulations(seefigure1a)areanotherfuturepossibility,ascylindersarealsousedfornanolithography.

DissipativeParticleDynamics

Cyclic-LinearBlendDomainSpacing

. Order-DisorderTransition(ODT)

Figure1:Basedonchainlengthandcomposition,blockcopolymersselfassembleintonanoscalemorphologies(a)1,2 whichhaveavarietyofapplications.Thisworkfocusesonthelamellar(banded)morphology(a)1,2CyclicBCPs(b)formfeatures20-40%smallerthantheirlinearanalogues.

Figure4:CoarsegrainingallowsDPDtosimulatelargesystemsoverlongperiodsoftime5.

Application- Blockcopolymerscanbeusedfornanolithography.Fortherequiredscale,

thewidthofthelamellarbands(featuresize)mustbeassmallaspossible.Oneinterestingwaytoreducedomainspacingistousecyclicblockcopolymers insteadoflinearones.

- Cyclicblockcopolymersaremuchmoredifficulttosynthesizethanlinearones.- Thisresearchusessimulationtotesttheeffectivenessofusingcyclicblock

copolymerasanadditiveintolinearblockcopolymersofsimilarcompositiontoreducedomainspacing.

- Theorder-disordertransitionisthepoint(χNvalue)whereablockcopolymertransitionsfromadisorderedstatetoanorderedone(seefigure1a).

- LowχNvaluescorrespondtolowerdomainspacingbutmaybebelowtheODT.

- Addingsmallamountsoforderedcyclicblockcopolymerstodisorderedlinearblockcopolymersmayinduceorder.

PureLinearN=12 10%CyclicBlend25%CyclicBlendPureCyclicN=24

Figure7:AtchainlengthsN=8,N=12,andN=16,thenormalized(dividedbytheirrespectivepurelineardomainspacing)domainspacinghasastronglinearrelationshipwithpercentcyclicBCPintheblend.Foreachsimulation,a=65.

a=35(lowχ)

a=65(highχ)

Figure9:ComparisonofblendsofLinearN=12andCyclicN=24(whichhavesimilarpuredomainspacings)atdifferentχ values.Atthelowerχ value,orderedcyclicblockcopolymersareblendedintodisorderedlinearblockcopolymers.Atthehigherχvalue,bothlinearandcyclicareordered.Thelowerχ valueresultsinlowerdomainspacing.Domainspacingsareonlymeasuredfororderedsystems.

BlockCopolymerSelfAssembly

Figure23:Alamellarblockcopolymerwithonepolymertyperemoved

Figure34:Theprocessofblockcopolymernanolithography

0.0

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g(r)

r

d

Figure5:DomainSpacingsaremeasuredusingradialdistributionfunctions.

Figure6:VisualMolecularDynamics(VMD)isusedtogeneratesnapshotsofthesimulatedpolymers.

AnalysisMethods

PureCyclic

N=8N=12N=16

a)

b)

PureCyclicd0N=16

PureLineard0

PureLinear

Blockcopolymers(BCPs)canbeusedastemplatesfornanolithography.Advancingtechnologydemandssmallerlithographicfeatures.CyclicBCPshavesmallerfeaturesthantheirlinearanaloguesbutaredifficulttosynthesizeinhighpurity.WeuseDPDsimulationtoinvestigatethepotentialofcyclicBCPsasanadditivetoshrinkdomainspacingoflinearBCPs.Wehavefoundastronglinearrelationshipbetweencycliccontentandreduceddomainspacing.Additionally,addinganorderedcyclicBCPcaninduceorderinanotherwisedisorderedlinearBCP.Thisapproachmayallowforfurthershrinkingofdomainspacing,asloweringtheparametersχ andNresultsinsmallerfeaturesbutpotentiallydisorderedsystems.

SCGL

Figure8:BlendsoflinearN=12+cyclicN=24ata=35(lowχ)showatransitionfromdisordertolamellarbetween10%cyclicand25%cyclic.r

dr

References

LinearN=12

CyclicN=24

PureCyclic