文档介绍：该【Thermal conductivity measurement of solid materials using an “ITX” method–A pilot study using DNA solid films 2021 Yoko Tomo 】是由【李十儿】上传分享，文档一共【6】页，该文档可以免费在线阅读，需要了解更多关于【Thermal conductivity measurement of solid materials using an “ITX” method–A pilot study using DNA solid films 2021 Yoko Tomo 】的内容，可以使用淘豆网的站内搜索功能，选择自己适合的文档，以下文字是截取该文章内的部分文字，如需要获得完整电子版，请下载此文档到您的设备，方便您编辑和打印。InternationalJournalofHeatandMassTransfer176(2021)121501
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InternationalJournalofHeatandMassTransfer
journalhomepage:
Thermalconductivitymeasurementofsolidmaterialsusingan“ITX”
method–ApilotstudyusingDNAsolidfilms
YokoTomoa,HibikiKogaa,TakanobuFukunagaa,KosakuKurataa,HisaoMatsunob,c,
∗
KeijiTanakab,c,HiroshiTakamatsua,
aDepartmentofMechanicalEngineering,KyushuUniversity,Fukuoka819-0395,Japan
bDepartmentofAppliedChemistry,KyushuUniversity,Fukuoka819-0395,Japan
cInternationalInstituteforCarbon-NeutralEnergyResearch(I2CNER),KyushuUniversity,Fukuoka819-0395,Japan
articleinfoabstract
Articlehistory:
Received16March2021thermalconductivityofnovelone-andtwo-dimensionalmaterialshaspreviouslybeenmeasuredusing
Revised27April2021aT-,themeasurementsare
Accepted15May2021
aso-calledITXmethod,whichdeterminestheinherentthermalconductivityofasamplefrommeasure-
Keywords:mentsmadeinthreegeometricconfigurations(“I”,“T”,and“X”shape)ofthesample,heatsinks,and
-
ITXmethodductivitycanbeaccuratelydeterminedirrespectiveoftherelativecontributionofthethermalcontact
Thermalconductivityresistancetotheoverallthermalresistance.
Solidmaterials
Thermalcontactresistance©2021TheAuthor(s).PublishedbyElsevierLtd.
DNAsolidfilmThisisanopenaccessarticleundertheCCBYlicense(/)
[15,16].Despitethis,thethermalconductivityofbulkpolymersde-
Polymersarehighlyversatilematerialswithindustrialandcon-pendsnotonlyonintramolecularthermaltransportbutalsoon
sumerapplicationsthatexploittheirhighformability,lightweight,,the
lowcost,-conductivityisan-mechanismsofthermaltransportinpolymersmustbeinvestigated
otheressentialfeature,makingthemusefulinsulatorsinmanybymeasuringtheirmacroscopicthermalconductivity.
electronicdevicesintheformofinterfacialmaterialsandflexibleDependingonthematerialandsamplepreparation,thether-
substrates[1–5].However,theirlowthermalconductivityisun-maltransportpropertiesofsolidmaterialshavebeenmeasuredus-
desirableforthermalmanagementbecauseitcausesatempera-ingthe3ωmethod[18,19],time-domainthermoreflectance[20,21],
tureriseinheat-generatingdevices,asituationthatalsoapplieslaserflashRamanspectroscopy[22,23],theT-typeprobemethod
tosomepolymernanocompositeswithsomefillers[6–8].Thishas[24-27],andlaserflashanalysis[6],thelatterofwhichismost
motivatedrecentstudiesthataimtoincreasethethermalcon-,theT-typeprobe
ductivityofpolymers[1,9,10],whichrangefrom62Wm−1K−1formethod(so-calledbecauseofthegeometricarrangementofthe
nanostructuredpolymerfilms[11],90Wm−1K−1forcrystallinesampleandprobe)hasbeenusedtomeasurethelongitudinalther-
polymernanofibers[12],104Wm−1K−-standinghot
nanofibers[13],andupto416Wm−1K−1forspidersilk[14].Re-film/wireasaheaterandaprobe[17],andmeasuresthetempera-
gardlessofwhetheritispossibletoobtainathermalconductivityturewithandwithoutasamplesuspendedbetweenthefilm/wire
ashighasthatofcopper,,thethermalconductivitiesof
conductivityofpolymerscanbemarkedlyincreased,whilstkeep-asinglecarbonnanotube[24]andgraphene[25,26]weresuccess-
ingthemelectricallynon-conductive,bycontrollingtheirmolec--typemethodisusefulforprobingfibersand
,amoleculardynamicssimulationindicatedotherlong,narrowmaterialsthatareelectricallynon-conductive.
Itisthereforesuitableformeasuringthelongitudinalthermalcon-
ductivityofpolymers,themagnitudeofwhichisexpectedtobe
∗-
E-mailaddress:******@-().phisticatedmethod,T-typeprobemeasurementmaybeaffectedby
/
0017-9310/©2021TheAuthor(s).(/)
,,(2021)121501
:(a)ahotwireonly(Iconfiguration);(b)ahotwirewithasingleheatpathviaasamplefromthejunctiontoa
heatsink(Tconfiguration);(c)ahotwirewithtwoheatpathsviaasamplefromthejunctiontoheatsinks(Xconfiguration);and(d)thetemperaturedistributioninthe
hotwireforeachconfiguration.
thethermalcontactresistancebetweentheprobeandthesample,
whichisdifficulttocontrolandestimatebecauseitdependsonthe(Xconfiguration)willfurtherdecreasethetemperatureofthewire.
-dimensionalheatconductionthroughthehot
thethermalcontactresistanceandtheinherentthermalresistancewireandthesample,withnoheattransferfromthesesurfacesby
ofthesample,thelatterofwhichdependsonthethermalcon-
,Th,intheIconfigurationisdeterminedfromthesolution
resistance,measurementshavethereforebeenmadeusingsamplestotheone-dimensionalheatconductionequationforauniformly
ofdifferentlengthswithasameprobe,whichenabledthethermalheatedwire:
conductivityofcarbonfiberstobemeasured[26,27].2
qvl
=h
Herein,weproposeasimplealternativemethodtosimulta-Th(1)
12k
neouslymeasurethethermalconductivityandthermalcontacth
,eachcontributiontotheoverallthermalwherelhandkharethelengthandthethermalconductivityof
transportisevaluatedbyconductingtwoexperimentswithdiffer-thehotwire,respectively,andqvistherateofvolumetricheat
entsamplearrangementsbutmaintainingthesamesample–
,asamplewithheatsinksconnectedatbothendsisofthehotwirebymeasuringTh.
attachedtothecenterofthehotwiretocreatetwoheatpaths(XTherelationshipbetweenThandtheoverallthermalresis-
configuration).Then,oneoftheheatpathsisremovedbycuttingtanceoftheheatpaththroughsamples,R,isderivedinamanner
asampleorremovingaheatsink(Tconfiguration).AlthoughthesimilartothatfollowedfortheT-
methodwasdevelopedforthinpolymerfibers,arelativelythickasthetemperatureatthejunctionofthehotwireandthesample,
filmwasfirstused,whichenabledthefeasibilityofthemethodweobtain
tobeassessedwithoutthedifficultyassociatedwithmanipulat-3+3−
lh1lh2qvTjT0
T=+(2)
,weusedade-h
12khlh2
oxyribonucleicacid(DNA)solidfilm[29],whosewatercontent
markedlyinfluencesitsmechanicalproperties,includingitsstress–fromthesolutiontotheheatconductionequations,whereT0is
straincurve[28,29].TheDNAfilm,whichisabiodegradable,non-thetemperatureoftheheatsinksandlh1andlh2arethelengths
=+
oil-basedmaterial,isexpectedtobeanewsustainablestructuralofthehotwireateachsideofthejunction,suchthatlhlh1lh2.
thebestofourknowledge,thisisthefirstreportonthethermaltothejunctionisequaltothatconductedtothesample,Qs:
−T0
Qs=(3)
R
:
(l3+l3)
2Th−h1h2
vhh
R=(4)
(l3+l3)
lh−1+12Th−h1h2
Ahkh
Theexperimentswereconductedusingthreedifferentgeomet-2lh1lh2qv6khlh
ricconfigurationsofahotwireandasample:thehotwirewithno
Theoverallthermalresistanceiscomposedofthethermalresis-
sample(Iconfiguration:(a));asamplesuspendedbetween
tanceofthesampleandthethermalcontactresistance,R,atthe
twoheatsinksandcontactedtothecenterofthehotwire(Xcon-c
figuration:(c));andthesamehotwire–samplecontactbut
heatpathintheTconfigurationandtwoparallelheatpathsinthe
withtheconnectiontooneoftheheatsinksremoved(Tconfig-
Xconfiguration().Hence,theoverallthermalresistancesin
uration:(b)).Thepresentapproachissimilartothatofthe
theTconfiguration(R)andtheXconfiguration(R)are:
T-typeprobemethod,wherethehotwireisusedasaself-heatedTX
thermometer,thedifferencebeingthatthetemperatureofthehotRT=Rc+Rs1(5)
wireismeasuredintheXconfigurationinadditiontotheIandand
RR
s1s2
Iconfiguration,thetemperaturerisesatitscenterbutnotattheR=Rc+(6)
X+
-Rs1Rs2
sultsinaparabolictemperaturedistributioninthesteady-state,aswherethethermalresistancesofeachheatpath,Rs1andRs2,are
(d).Ifasampleconnectedtoaheatsinkisincon-expressedby
tactwiththecenterofthehotwire(Tconfiguration),heatcon-l
=s1
ductionthroughthesamplewillcausethetemperatureofthehotRs1(7)
ksAs1
2
,,(2021)121501
(a)theXconfigurationwithtwoheatpathsthroughthesampleand(b)theTconfigurationwithoneheatpaththroughthesample.
Table1
ls2Sampleandsensordimensions.
Rs2=(8)
ksAs2Sample1Sample2Sample3
Here,ksisthethermalconductivityofthesample,ls1andls2Hotwirelh1(mm)
l(mm)
arethesamplelengthseithersideofthejunction,andAs1andAs2h2
Sample(DNAfilm)l(mm)
aretheirrespectivecross-.(5)–(8),weob-s1
ls2(mm)
tain2
As1(mm)
A(mm2)
2s2
ls1As2∗
ks=(9)ts1(mm)
(+)(−)∗
As1As1ls2As2ls1RTRXts2(mm)
∗
ws1(mm)
∗
As1ls2As1ls2ws2(mm)
R=1+R−R(10)
cXT∗
As2ls1As2ls1t:thickness,w:width
Therefore,oncewemeasuretheoverallthermalresistances,RT
andRX,
IntheT-typemethod,onlyRTismeasuredduringtheexperi-
ment,andthusthethermalconductivityisdeterminedfromattachedtoeachendofthetwocopperheatsinksthatalsoserved
aselectrodes,(a).Thevoltagedropatthehot
ls1
ksT=(11)wirewasmeasuredusingafour-terminalmethodthatseparated
AR
s1Tthevoltage-measuringcircuitfromthepowersupplycircuit.
−
,fortheXcon-Theexperimentwasconductedatthepressureof1×104Pain
figuration,-
llinumwireusingaDCpowersupply(KEYSIGHTB2901A,Keysight
=s1s2
ksX(12)Technologies,USA),weuseddigitalvoltmeters(KEITHLEY2002,
(As1ls2+As2ls1)RX
KeithleyInstruments,USA)tomeasurethevoltagedropacrossthe
-standardresistorinstalledinthe
ADNAsolidfilmwaspreparedusingasolvent-castingmethodconfiguration,thevoltagewasmeasuredatfivedifferentheating
/
describedbyMatsunoetal.[28].Briefly,DNAfromsalmonspermratestoobtainThqvinEq.(4).Themeasurementwasfirstper-
(Deoxyribonucleicacidsodiumsalt,,MPBiomed-formedintheIconfigurationatnominalsubstratetemperatures
icalsLLC,USA)waspurifiedbyethanol-precipitationmethod,andof10,20,30,and40°Ctocalibratetheelectricalresistanceofthe
%.-
solutionwascastinarectangularmoldandleftatroomtemper-turecouldthenbedeterminedbyextrapolationofthelinearrela-
-tionshiptoexcludetheeffectoftemperatureriseduetoheating.
mately40timestoobtainafilmwithathicknessofafewhundredAfterobtainingtherelationshipbetweenelectricalresistan