电场对FOTS自组装分子膜SiO2界面作用特性的影响

37　2大连海事大学学报Vol.37　No.220115JournalofDalianMaritimeUniversityMay,　2011:1006-7736(2011)02-0127-04FOTSSiO2刘　硕,连　峰,张会臣(,　116026):为研究电场对自组装分子膜摩擦学特性的影响,采用分子动力学模拟软件MaterialsStudio5.0计算不同电场强度和作用方向下FOTS自组装分子膜与SiO2基底的界面结合能.结果表明:当电场强度小于3.0×108Vm时,施加正负方向电场,界面结合能均增大,而施加正电场的界面结合能增大较多,但在正负方向电场作用下界面结合能随着场强的增加变化幅度较小.对FOTS与SiO2基底相互作用能的分析得知,影响体系结合能的主要因素是两者之间的范德华力,其中色散力起主要作用.:FOTS;SiO2基底;结合能;分子动力学模拟:TH117.1　　　　　:AInterfacialcontactcharacteristicsbetweenFOTSSAMsandSiO2underelectricfieldLIUShuo,LIANFeng,ZHANGHuichen(TransportationandLogisticsEngineeringCollege,DalianMaritimeUniversity,Dalian116026,China)Abstract:MoleculardynamicssimulationsoftwarepackageMa-terialsStudio5.0wasusedtocalculatethebindingenergybe-tweenself-assembledmonolayerFOTSandSiO2substrateatdif-ferentelectricfieldstrengthsanddirections.Resultsshowthattheinterfacebindingenergybothincreaseswhethertheappliedelectricfieldispositiveornegativewhentheelectricfieldstrengthislessthan3.0×108Vm,whiletheinterfacebindingenergyforthepositiveelectricfieldincreasesmore.Butthebindingenergyoftheinterfacechangesalittlewhenboththepositiveandnegativeelectricfieldstrengthsincrease.Atthesametime,theinteractionenergybetweenFOTSandSiO2sub-stratewasanalyzed,andtheresultsshowthatthekeyinfluenc-ingfoctorforthebindingpropertyistheVanderWaalsforceinthesystem,andthecontributionofdispersiveforceinvanderWaalsforceisthemostimportantone.Keywords:FOTS;SiO2substrate;bindingenergy;moleculardy-namicssimulation0　引　言,[1].,、、[2].[3-4].,,[5-6]..[7],σ=26.55μCcm2,;σ=35.4μCcm2,(100).[8]Al(100),Al(100),.[9],,.、、.FOTSSiO2,FOTS,:2010-12-13.:(2008S029).:　(1986-),,,,E-mail:[e-mail].:　(1965-),,,,,E-mail:[e-mail]:10.16411/j.cnki.issn1006-7736.2011.02.002.1　研究方法1.1　MaterialsStudio5.0,SiO2,MaterialsStudioVisuali-zerCleaveSurface(100),FracionalDepth1.3386nm.SiO2(100)Forcite,SiO2(100),BuildSymmetrySurpercellU×V=5×5,BuildCrys-talsBuildVacuumSlad2D3D,0.0nm.SiO2(100)1,a=2.457nm,b=2.703nm,c=1.339nm,α=β=γ=90°.1　SiO2(100)1H,1H,2H,2H-(CF3(CF2)5(CH2)2SiCl3,FOTS):FOTSMSVisualiarFOTS,BuildPolymer8FOTS,AmorphousCellFOTS,a、bSiO2(100)a、b,.FOTSa=2.457nm,b=2.703nm,c=1.023nm,α=β=γ=90°.2.SiO2(100)8FOTSBuildLayers.,1SiO2(100),2FOTS3nm,,3(a).3(a)2　FOTS,1SiO2(100)1.7nm,2FOTS,3SiO2(100),1,3(b),FOTS3nm..3　SiO2(100)FOTS1.2　SiO2(100)FOTSMSForcite.,3(a)、(b).3(a)(FOTS);3(b)(SiO2).:COMPASS;,Nose;smart,;medium,298K,1fs;50ps;50000;(NVT).50ps,AmorphousCell,298K,1.65×105～3.0×108Vm.3(b),.128　　　　　　　　　　　　　　　　　　大连海事大学学报　　　　　　　　　　　　　第37卷　2　模拟结果与分析2.1　.SiO2(100)FOTSEinter=ET-(EFOTS+ESiO2)(1):ETSiO2(100)FOTS;EFOTSSiO2FOTS;ESiO2FOTSSiO2(100).(Ebind),Ebind=-Einter.SiO2(100)FOTS,,SiO2(100)FOTS.4,:E3.0×108Vm,,,;,.FOTS,.4　2.2　SiO2(100)FOTS,,,.E=1.65×105Vm,1.1:SiO2(100)FOTSEtotal,,;FOTSEFOTS,,.,、,.Einter,SiO2(100)FOTS,-125.19Jmol,38.54Jmol,3.,5.,,,;,,.2.3　4:E3.0×108Vm,SiO2(100)FOTS;,.SiO2(100)FOTSE3.0×108Vm,;,,.3　结　论(1)SiO2(100)FOTS,.1　JmolEnergyEinterEtotalEFOTSESiO2-86.530000.04-86.6538.54-125.190.13-128747.142037.923388.31-4493.00-814.06-4101.755752.22-9853.97-124764.56-1239.87905.10593.10-1947.63-1020.67-15.681292.96-1308.63245.87-127420.741132.822795.21-2545.37206.58-3999.424420.73-8420.15-125010.55129第2期　　　　　　　刘　硕,等:电场对FOTS自组装分子膜SiO2界面作用特性的影响　　　　　　　5　　　(2)SiO2(100)FOTS,FOTS.E3.0×108Vm,,;,;.,,.(References):[1]HEDH,MANORYRR,HARRYS.Aslidingwear　testerforoverheadwiresandcurrentcollectorsinlightrailsystems[J].Wear,2000,239:10-20.[2]HEDH,MANORYRR.Anovelelectricalcontactmate-rialwithimprovedself-lubricationforrailwaycurrentcollec-tors[J].Wear,2001,249:626-636.[3],.-[J].,2000,20(6):435-438.[4],,.[J].,2003(2):56-57.[5],,.[J].,2004,16(2):291-298.[6],,,.[J].,2005,18(1):169-174.[7]XIAXF,BERKOWITZML.Electric-fieldinducedres-tuctueingofwaterataplatinum-waterinterface:amolecu-lardynamiccomputersimulation[J].PhysicalReviewLet-ters,1995,74:3193-3196.[8]SANKARANARAYANANSK,KAXIRASE,RA-MANATHANS.AtomisticsimulationoffieldenhancedoxidationofAl(100)beyondthemottpotential[J].PhysicalReviewLetters,2009,102:095504.[9]HAMADIA,NOVOTNYMA,WIPFCDO,etal.Anewbattery-chargingmethodsuggestedbymoleculardy-namicssimulations[J].PhysicalChemistry,2010,12:2505-2764.130　　　　　　　　　　　　　　　　　　大连海事大学学报　　　　　　　　　　　　　第37卷