Perpendicular\nPhase Separation in Confined Binary\nLiquids: Unveiling Novel Kinetics and Stabilization Mechanisms for\nNanofilms

We investigated the dynamics of a binary mixture confined\nwithin\nvan der Waals walls using molecular dynamics simulations. We discovered\na novel phenomenon named perpendicular separations of two phases (PSTP).\nIn the initial stage, central water molecules diffused, subsequently\ncondensing symmetrically within the confinement’s midplane.\nIn the later stage, as water droplets nucleate and grow, the resin\nseparates perpendicularly into two films due to the action of bubblers\nand vdW walls, resulting in a hollow nanochannel. The mechanisms and\nconditions underlying PSTP are discussed. The results indicate that\nthe concentration (<i>C</i>) of resin in the middle region\nis linearly decreased with temporal power (<i>C</i>(<i>t</i>,<i>T</i>) ∝ <i>a</i>(<i>T</i>)<i>t</i><sup>1/3</sup>). We propose a new mechanism\nfor stabilizing nanochannels and films: dynamic “soft pillars”\nthat prevent Rayleigh-like instability. Our findings could shed light\non the manufacture of nanofilms and organic nanochannels, which could\nhelp advance biodetection and energy fields.