TY - JOUR AU - Sivebaek, I. M. AU - Samoilov, V. N. AU - Persson, Bo TI - Effective Viscosity of Confined Hydrocarbons JO - Physical review letters VL - 108 IS - 3 SN - 1079-7114 CY - College Park, Md. PB - APS M1 - FZJ-2015-04099 SP - 036102 PY - 2012 AB - We present molecular dynamics friction calculations for confined hydrocarbon films with molecular lengths from 20 to 1400 carbon atoms. We find that the logarithm of the effective viscosity ηeff for nanometer-thin films depends linearly on the logarithm of the shear rate: logηeff=C−nlogγ˙, where n varies from 1 (solidlike friction) at very low temperatures to 0 (Newtonian liquid) at very high temperatures, following an inverse sigmoidal curve. Only the shortest chain molecules melt, whereas the longer ones only show a softening in the studied temperature interval 0<T<900 K. The results are important for the frictional properties of very thin (nanometer) films and to estimate their thermal durability. LB - PUB:(DE-HGF)16 UR - <Go to ISI:>//WOS:000299329100019 DO - DOI:10.1103/PhysRevLett.108.036102 UR - https://juser.fz-juelich.de/record/201805 ER -