AI 中文总结
该研究针对固液界面超快结构动力学研究中面临的挑战，提出创建和表征超薄表面附着自由流动液膜的方法，利用撞击射流和气体辅助成型，实现超快时间分辨率，为掠入射散射实验提供稳定平台。
AI 中文摘要
捕捉固液界面发生的超快结构动力学是理解催化和界面化学反应中吸附、解吸、扩散和聚集过程的关键。掠入射几何中的硬X射线散射原则上可以以埃级结构灵敏度和超快时间分辨率获取界面结构变化。然而，液体样品内光泵浦和硬X射线脉冲的长光路对该实验方案的时间分辨率、信噪比和整体稳定性构成重大挑战。本文报告了一种创建和表征超薄表面附着自由流动液膜的方法，其亚微米厚度实现了超快时间分辨率并减少了体液体散射贡献。撞击射流几何产生稳定的微米级液膜，其形态系统地取决于入射角、射流速度和毛细管直径。使用第二个毛细管的气体辅助成型进一步使液膜变窄变薄，产生扩展的超薄区域并将乙腈的测量最小厚度降低到500纳米以下。所得平台为掠入射散射实验提供了可重复、连续流动、表面附着的液体几何结构。
英文摘要
Capturing the ultrafast structural dynamics that occur at the solid-liquid interface is key to understanding adsorption, desorption, diffusion, and aggregation processes in catalysis and interfacial chemical reactions. Hard-X-ray scattering in grazing-incidence geometry can, in principle, access interfacial structural changes with angstrom-scale structural sensitivity and ultrafast temporal resolution. However, the long optical paths of the optical pump and hard-X-ray pulses inside the liquid sample pose significant challenges to the temporal resolution, signal-to-noise ratio, and overall stability of such an experimental scheme. Here, we report a method for creating and characterizing ultrathin surface-attached free-flowing liquid sheets, whose submicrometer thickness enables ultrafast temporal resolution and reduces the bulk-liquid scattering contribution. The impinging-jet geometry produces stable micrometer-scale sheets whose morphology depends systematically on incidence angle, jet velocity, and capillary diameter. Gas-assisted shaping using a second capillary further narrows and thins the sheet, producing an extended ultrathin region and reducing the measured minimum thickness below 500~nm for acetonitrile. The resulting platform provides a reproducible, continuously flowing, surface-attached liquid geometry for grazing-incidence scattering experiments.
Comments10 pages, 6 figures
