论文标题
直接测量毛细血管含量的酒精纳米香肠中曲率依赖性表面张力
Direct Measurement of Curvature-Dependent Surface Tension in a Capillary-Condensed Alcohol Nanomeniscus
论文作者
论文摘要
表面张力是从相变的初始阶段理解成核的关键参数。尽管已经预测表面张力会随液体蒸气界面的曲率而变化，尤其是在较大的曲率下，例如，亚纳米计临界核核的大曲率，但由于无法访问如此小的群集，实验研究仍然具有挑战性。在这里，通过直接使用原子力显微镜测量单个毛细管构函的纳米杆菌的临界大小，我们解决了醇的表面张力的曲率依赖性，并观察到乙醇和N-丙醇的表面张力与左右的NM半径加倍。我们还发现，较大的负（正）曲率的界面表现出较大（较小的）表面张力，这显然控制了〜1 nm尺度的成核，表明比正常预期的促进成核更大。如此良好的特征曲率效应有助于更好地理解和准确分析在包括材料科学和大气科学在内的各个领域发生的成核。
Surface tension is a key parameter for understanding nucleation from the very initial stage of phase transformation. Although surface tension has been predicted to vary with the curvature of the liquid-vapor interface, particularly at the large curvature of, e.g., the subnanometric critical nucleus, experimental study still remains challenging due to inaccessibility to such a small cluster. Here, by directly measuring the critical size of a single capillary-condensed nanomeniscus using atomic force microscopy, we address the curvature dependence of surface tension of alcohols and observe the surface tension is doubled for ethanol and n-propanol with the radius-of-curvature of ~ -0.46 nm. We also find that the interface of larger negative (positive) curvature exhibits the larger (smaller) surface tension, which evidently governs nucleation at ~ 1 nm scale, indicating more facilitated nucleation than normally expected. Such well characterized curvature effects contribute to better understanding and accurate analysis of nucleation occurring in various fields including material science and atmospheric science.
