Intrinsic Stress Network and the Perception of Surface Tension

The evolution of the intrinsic liquid-vapour interface of a Lennard-Jones fluid owing to temperature variation is examined through molecular dynamics simulations employing the intrinsic sampling method (ISM) with a moving frame of reference. Results suggest, in good agreement with capillary wave theory, clear dampening effect on the density profiles as temperature increases. Further to this, an increase in temperature consequences in a decrease in the space filling nature (fractal dimension) of the stress-clusters at the surface.  A percolation analysis of these clusters indicates that a surface at a higher temperature is more disconnected in terms of stress-field, and it is precisely this fragile nature of the surface that results in an overall lower surface tension.