Symmetry Breaking in Meniscus Splitting: Effects of Boundary Conditions and Polymeric Membrane Growth.

An evaporative interface creates a non-equilibrium state for both dissolved molecules and geometrically asymmetric macrostructures such as those involved in crystal growth. The phenomenon of meniscus splitting has been discovered and hydrodynamically demonstrated using a Hele-Shaw cell by drying a viscous polymer solution/dispersion. The generation of multiple nuclei has been reported; however, the relative nuclei positions and dominant factors remain unclear. This study investigates meniscus splitting involving multiple nucleation events, focusing on symmetry breaking and asynchronous nucleus formation. Fundamentally, it is found that rather than splitting into halves or thirds, the splitting is uneven. With the cell width setting the boundary conditions, the nucleus is not generated at the center of the cell width, but rather is shifted to an asymmetric position, as shown by the statistical analysis of the nuclei positions. The shift strongly facilitates asynchronous second nucleation. Such deviations from symmetry and synchrony are crucial for interpreting dissipative structures and their time evolution.