Energy-Based Interface Detection for Phase Change Processes of Monatomic Fluids in Nanoconfinements

Nanoscale Meniscus Dynamics in Evaporating Thin Films: Insights from Molecular Dynamics Simulations

Evaporation studies are focused on unraveling heat transfer and flow dynamics near the solid-liquid-vapor contact line, particularly focusing on the meniscus, which encompasses the nonevaporating adsorbed layer, thin-film, and bulk meniscus regions. Continuum models assume that there are no evaporating adsorbed layers due to the strong intermolecular forces. However, recent molecular dynamics (MD) simulations have unveiled the significant role of adsorbed layers in thin-film evaporation. Leveraging a recently published energy-based interface detection method, the current study presents nonequilibrium MD simulation results for thin-film evaporation from a phase-change-driven nanopump using liquid argon confined between parallel platinum plates. Notably, unlike the transient simulations often encountered in the literature, the simulation system achieves a statistically steady transport. In this context, we showcase the shapes of the evaporating menisci for two distinct channel heights, 8 and 16 nm, and elucidate the underlying flow physics through velocity vectors and temperature contours. This comprehensive investigation advances our understanding of thin-film evaporation and its mechanisms, offering insights that span from nanoscale phenomena to broader thermal management applications.

Bacterial cellulose-based film with self-floating hierarchical porous structure for efficient solar-driven interfacial evaporation

Interface solar water evaporation is a mean of rapidly evaporating water using solar energy. However, it is still a challenge to obtain solar evaporators with simple assembly, durability and high photothermal performance. Here, we demonstrated an effective post foaming strategy for treating nitrogen-doped reduced graphene oxide/bacterial cellulose film (F-NRGO@BC) prepared by a simple in situ culture method. The composite film contains hierarchical porous structure and bubbles on the film, achieving an integrated self-floating interface evaporator with excellent light absorption (96.5 %) and high toughness (200.18 kJ m-3). Porous structure and low enthalpy of F-NRGO@BC make a high evaporation rate of 1.68 kg m-2 h-1 and a low thermal conductivity of 0.644 W m-1 K-1 to ensure effective energy efficiency and heat insulation. This design of controlling surface morphology and internal structure provides a novel way for large-scale preparation and high-performance evaporator.