Rupture mechanism of liquid crystal thin films realized by large-scale molecular simulations

Journal Article · Wed Jan 01 00:00:00 EST 2014 · Nanoscale

DOI:https://doi.org/10.1039/c3nr05413f· OSTI ID:1130435

Nguyen, Trung D ^[1]; Carrillo, Jan-Michael Y ^[1]; Brown, W Michael ^[1]; Matheson, Michael A ^[1]

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1. ORNL

The ability of liquid crystal (LC) molecules to respond to changes in their environment makes them an interesting candidate for thin film applications, particularly in bio-sensing, bio-mimicking devices, and optics. Yet the understanding of the (in)stability of this family of thin films has been limited by the inherent challenges encountered by experiment and continuum models. Using unprecedented largescale molecular dynamics (MD) simulations, we address the rupture origin of LC thin films wetting a solid substrate at length scales similar to those in experiment. Our simulations show the key signatures of spinodal instability in isotropic and nematic films on top of thermal nucleation, and importantly, for the first time, evidence of a common rupture mechanism independent of initial thickness and LC orientational ordering. We further demonstrate that the primary driving force for rupture is closely related to the tendency of the LC mesogens to recover their local environment in the bulk state. Our study not only provides new insights into the rupture mechanism of liquid crystal films, but also sets the stage for future investigations of thin film systems using peta-scale molecular dynamics simulations.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1130435
• Journal Information: Nanoscale, Vol. 6, Issue 6; ISSN 2040-3364
• Country of Publication: United States
• Language: English