When liquids are confined into a nanometer-scale slit, the induced layering-like film
structure allows the liquid to sustain non-isotropic stresses and thus be load-bearing. Such anisotropic
characteristics of liquid under confinement arise naturally from the liquids’ wavenumber dependent
compressibility, which does not need solidification to take place as a prerequisite. In other words,
liquids under confinement can still retain fluidity with molecules being (sub-)diffusive. However, the
extensively prolonged structural relaxation times can cause hysteresis of stress relaxation of confined
molecules in response to the motions of confining walls and thereby rendering the quasi-static stress
tensors history-dependent. In this work, by means of molecular dynamics, stress tensors of a highly
confined key base-oil component, i.e., 1-decene trimer, are calculated after its relaxation from being
compressed and decompressed. A maximum of 77.1 MPa normal stress discrepancy has been detected
within a triple-layer boundary film. Analyses with respect to molecular morphology indicate that
among the effects (e.g., confinement, molecular structure, and film density) that can potentially affect
confined stresses, the ordering status of the confined molecules plays a predominant role
