화학공학소재연구정보센터
Journal of Physical Chemistry B, Vol.111, No.39, 11354-11365, 2007
Crystal bridges, tetratic order, and elusive equilibria: The role of structure in lubrication films
In this paper, we report on molecular dynamics simulation studies of thin dodecane films confined between mica surfaces. On confinement, the film undergoes a surface-mediated transition into a novel phase characterized by tetratic orientational order. The rheology of this ordered film is governed by slip planes and, at low shear rates, stick-slip behavior observable under steady shear rates. Melting of these films was observed either on heating or on exceeding a critical shear rate. Evidence is presented that this tetratic film is not the true equilibrium state; rather, a state characterized by nematic order and very low viscosities is found to be more stable.