Vapor-to-liquid phase change condensation is routinely observed in numerous industrial processes 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11. In addition to the new coating approach, the insights gained from this work present a strategy to minimize oil depletion during condensation from lubricated surfaces. Importantly, compared to the fast-degrading dropwise condensation, the inverse opal coated copper tubes maintained high heat transfer rates when the experiments were repeated > 20 times each experiment lasting 3–4 h. ![]() Furthermore, our results show that impregnating the porous structure with oil further improves the heat transfer coefficient by an additional 30% to ≈ 103 kW/m 2 K. In our experiments, the cracks improved the heat transfer coefficient from ≈ 12 kW/m 2 K for laminar filmwise condensation on smooth clean copper tubes to ≈ 80 kW/m 2 K for inverse opal coated copper tubes nearly a sevenfold increase from filmwise condensation and identical enhancement with state-of-the-art dropwise condensation. Importantly, the high hydraulic conductivity of the cracks promote axial condensate transport that is beneficial for condensation heat transfer. In this work, we show rapid condensate transport through cracks that formed due to material shrinkage when a copper tube is coated with silica inverse opal structures. In both filmwise and dropwise modes, the condensate is removed when gravity overcomes pinning forces. ![]() Since the 1930s, it is well understood that vapor condenses in filmwise mode on clean metallic surfaces whereas it condenses by forming discrete droplets on surfaces coated with a promoter material. ![]() Phase-change condensation is commonplace in nature and industry.
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