  Confinement breaks the translational symmetry of materials. Such symmetry
breaking can be used to obtain configurations that are not otherwise accessible
in the bulk. Here, we explore the effect of substrate-liquid interactions on
the induced thermodynamic and kinetic anisotropies. We consider n-octane
nanofilms that are in contact with substrates with varying degrees of
attraction. Complete freezing of octane nanofilms is observed at low
temperatures, while at intermediate temperatures, a frozen monolayer emerges at
both interfaces. By carefully inspecting the profiles of translational and
orientational relaxation times, we confirm that the translational and
orientational degrees of freedom are decoupled at these frozen monolayers. At
sufficiently high temperatures, however, free interfaces and solid-liquid
interfaces close to loose substrates undergo pre-freezing, characterized by
mild peaks in several thermodynamic quantities. Two distinct dynamic regimes
are observed. The dynamics is accelerated in the vicinity of loose substrates,
while sticky substrates decelerate dynamics, sometimes by as much as two orders
of magnitude. These two distinct dynamical regimes have been previously by us
[JCP 141: 024506, 2014] for a model atomic glass-forming liquid. We also
confirm the existence of two correlations proposed in the above-mentioned work
in solid-liquid subsurface regions of octane films, i.e., a correlation between
density and normal stress, and between atomic translational relaxation time and
lateral stress. Finally, we inspect the ability of different regions of a film
to explore the potential energy landscape, and observe no noticeable difference
between the free surface and the bulk. This is unlike the films of model atomic
glass formers that tend to sample their respective landscape more efficiently
at free surfaces.
