000012966 001__ 12966 000012966 005__ 20180208201200.0 000012966 0247_ $$2pmid$$apmid:20210317 000012966 0247_ $$2DOI$$a10.1021/la904476d 000012966 0247_ $$2WOS$$aWOS:000277928100141 000012966 037__ $$aPreJuSER-12966 000012966 041__ $$aeng 000012966 082__ $$a670 000012966 084__ $$2WoS$$aChemistry, Multidisciplinary 000012966 084__ $$2WoS$$aChemistry, Physical 000012966 084__ $$2WoS$$aMaterials Science, Multidisciplinary 000012966 1001_ $$0P:(DE-HGF)0$$aSivebaek, I.M.$$b0 000012966 245__ $$aVelocity Dependence of Friction of Confined Hydrocarbons 000012966 260__ $$aWashington, DC$$bACS Publ.$$c2010 000012966 300__ $$a8721 - 8728 000012966 3367_ $$0PUB:(DE-HGF)16$$2PUB:(DE-HGF)$$aJournal Article 000012966 3367_ $$2DataCite$$aOutput Types/Journal article 000012966 3367_ $$00$$2EndNote$$aJournal Article 000012966 3367_ $$2BibTeX$$aARTICLE 000012966 3367_ $$2ORCID$$aJOURNAL_ARTICLE 000012966 3367_ $$2DRIVER$$aarticle 000012966 440_0 $$04081$$aLangmuir$$v26$$x0743-7463$$y11 000012966 500__ $$aA part of the present work was carried out in frames of the European Science Foundation EUROCORES Programme FANAS supported from the EC Sixth Framework Programme, under Contract N. ERAS-CT-2003-980409. I.M.S. and V.N.S. acknowledge support from IFF, FZ-Julich, as well as hospitality and help of the staff during their research visits. 000012966 520__ $$aWe present molecular dynamics friction calculations for confined hydrocarbon "polymer" solids with molecular lengths from 20 to 1400 carbon atoms. Two cases are considered: (a) polymer sliding against a hard substrate and (b) polymer sliding on polymer. We discuss the velocity dependence of the frictional shear stress for both cases. In our simulations, the polymer films are very thin (approximately 3 nm), and the solid walls are connected to a thermostat at a short distance from the polymer slab. Under these circumstances we find that frictional heating effects are not important, and the effective temperature in the polymer film is always close to the thermostat temperature. In the first setup (a), for hydrocarbons with molecular lengths from 60 to 1400 carbon atoms, the shear stresses are nearly independent of molecular length, but for the shortest hydrocarbon C(20)H(42) the frictional shear stress is lower. In all cases the frictional shear stress increases monotonically with the sliding velocity. For polymer sliding on polymer (case b) the friction is much larger, and the velocity dependence is more complex. For hydrocarbons with molecular lengths from 60 to 140 C atoms, the number of monolayers of lubricant increases (abruptly) with increasing sliding velocity (from 6 to 7 layers), leading to a decrease of the friction. Before and after the layering transition, the frictional shear stresses are nearly proportional to the logarithm of sliding velocity. For the longest hydrocarbon (1400 C atoms) the friction shows no dependence on the sliding velocity, and for the shortest hydrocarbon (20 C atoms) the frictional shear stress increases nearly linearly with the sliding velocity. 000012966 536__ $$0G:(DE-Juel1)FUEK412$$2G:(DE-HGF)$$aGrundlagen für zukünftige Informationstechnologien$$cP42$$x0 000012966 588__ $$aDataset connected to Web of Science, Pubmed 000012966 650_2 $$2MeSH$$aHydrocarbons: chemistry 000012966 650_2 $$2MeSH$$aPolymers: chemistry 000012966 650_7 $$00$$2NLM Chemicals$$aHydrocarbons 000012966 650_7 $$00$$2NLM Chemicals$$aPolymers 000012966 650_7 $$2WoSType$$aJ 000012966 7001_ $$0P:(DE-HGF)0$$aSamoilov, V.N.$$b1 000012966 7001_ $$0P:(DE-Juel1)130885$$aPersson, B. N. J.$$b2$$uFZJ 000012966 773__ $$0PERI:(DE-600)2005937-1$$a10.1021/la904476d$$gVol. 26, p. 8721 - 8728$$p8721 - 8728$$q26<8721 - 8728$$tLangmuir$$v26$$x0743-7463$$y2010 000012966 8567_ $$uhttp://dx.doi.org/10.1021/la904476d 000012966 909CO $$ooai:juser.fz-juelich.de:12966$$pVDB 000012966 915__ $$0StatID:(DE-HGF)0010$$aJCR/ISI refereed 000012966 9141_ $$y2010 000012966 9131_ $$0G:(DE-Juel1)FUEK412$$aDE-HGF$$bSchlüsseltechnologien$$kP42$$lGrundlagen für zukünftige Informationstechnologien (FIT)$$vGrundlagen für zukünftige Informationstechnologien$$x0 000012966 9201_ $$0I:(DE-Juel1)VDB781$$d31.12.2010$$gIFF$$kIFF-1$$lQuanten-Theorie der Materialien$$x0 000012966 970__ $$aVDB:(DE-Juel1)124743 000012966 980__ $$aVDB 000012966 980__ $$aConvertedRecord 000012966 980__ $$ajournal 000012966 980__ $$aI:(DE-Juel1)PGI-1-20110106 000012966 980__ $$aUNRESTRICTED 000012966 981__ $$aI:(DE-Juel1)PGI-1-20110106