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纳米尺度下液体的蒸发因微观效应的影响而显著增强, 其速率甚至超过经典赫兹-克努森方程的预测上限. 这一特性使纳米液体蒸发在太阳能界面蒸发、电子散热及微流控等领域展现出重要应用价值. 然而, 现有研究多聚焦于单一微观效应的影响, 对多种效应协同作用机制的认识仍显不足. 为了准确地描述纳米尺度下液体的相变行为, 本研究以液氩为对象, 系统探讨了纳米尺度下液氩的势能与空化效应协同作用对液氩蒸发的影响机制. 采用分子动力学模拟研究在不同固-液相互作用强度的纳米通道内液氩的蒸发, 结果表明固-液相互作用强度增大使液氩势能减小, 蒸发能垒增大理论上抑制其蒸发. 但由此所形成的毛细压力诱导液氩内部负压而形成的空化效应增大了液氩的蒸发面积, 进而促进液氩的蒸发, 并且还伴随着蒸发模式的转变. 结果表明, 在 $ {\varepsilon }_{\mathrm{s}\mathrm{l}}=0.5{\varepsilon }_{\mathrm{l}\mathrm{l}} $, $ {\varepsilon }_{\mathrm{s}\mathrm{l}}={\varepsilon }_{\mathrm{l}\mathrm{l}} $, $ {\varepsilon }_{\mathrm{s}\mathrm{l}}=2{\varepsilon }_{\mathrm{l}\mathrm{l}} $, $ {\varepsilon }_{\mathrm{s}\mathrm{l}}=4{\varepsilon }_{\mathrm{l}\mathrm{l}} $四种不同固-液相互作用强度的通道中, 液氩的蒸发速率依次为3.95×10–14, 3.49×10–14, 3.02×10–14, 2.44×10–14 kg/s, 可得出在中等固-液相互作用强度$ {\varepsilon }_{\mathrm{s}\mathrm{l}}={\varepsilon }_{\mathrm{l}\mathrm{l}} $下, 二者达到最佳的协同效果, 蒸发速率达到最大值.Liquid evaporation on a nanoscale is significantly strengthened by microscopic effects, with its rate even exceeding the predicted upper limit of the classical Hertz-Knudsen equation. This property makes nanoscale liquid evaporation highly valuable for applications in solar-driven interfacial evaporation, electronics cooling, and microfluidics. However, existing research predominantly focuses on the influence of individual microscopic effects, leaving the synergistic mechanisms of multiple effects to be poorly understood. To deeply reveal the microscopic mechanism of liquid phase change on a nanoscale, this study employs liquid argon as a model system to systematically investigate the synergistic effect of potential energy and cavitation on its evaporation. Using molecular dynamics simulations, we study the evaporation process of liquid argon within nanochannels characterized by different solid-liquid interaction strengths under identical temperature and time frame. The results indicate that an increase in the solid-liquid interaction strength reduces the average potential energy of liquid argon and increases the evaporation energy barrier, which theoretically should suppress the evaporation. Nevertheless, the capillary pressure induced by the increased meniscus curvature leads to negative pressure within the liquid argon, triggering a cavitation effect. This cavitation generates bubbles inside the liquid argon, which significantly increases the evaporation surface area and consequently promotes evaporation. Furthermore, the meniscus-dominated evaporation mode is gradually weakened, while the contribution from cavitation bubbles becomes increasingly pronounced. This study demonstrates that the evaporation rates of liquid argon in the four nanochannels with different interaction strengths are 3.49 × 10–14, 3.95 × 10–14, 3.02 × 10–14, and 2.44 × 10–14 kg/s, respectively. Therefore, it can be concluded that the evaporation rate does not vary linearly with the increase of solid-liquid interaction strength. On the contrary, under moderate interaction intensity, the optimal synergistic state between potential energy and the cavitation effect is achieved, thereby obtaining a maximum evaporation rate.
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Keywords:
- molecular dynamics /
- nanoscale evaporation /
- liquid argon potential energy /
- cavitation effect /
- synergistic interaction
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固-液势能
强度$ {\varepsilon }_{\mathrm{s}\mathrm{l}} $R/nm $ \gamma $/(mN·m–1) $ {P}_{\mathrm{c}} $/bar $ {P}_{\mathrm{v}} $/bar $ {P}_{\mathrm{l}} $/bar $ {\varepsilon }_{\mathrm{l}\mathrm{l}} $ 1.25 9.15 73.20 3.22 –69.98 2$ {\varepsilon }_{\mathrm{l}\mathrm{l}} $ 1.23 9.3 75.61 2.82 –72.79 4$ {\varepsilon }_{\mathrm{l}\mathrm{l}} $ 1.24 9.24 74.52 2.99 –71.53 
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