This review offers a succinct overview of the development of a vacuum-compatible microfluidic reactor system for analysis at the liquid vacuum interface (SALVI), and its diverse applications in in situ, in vivo, and in operando imaging of liquid surfaces as well as the air-liquid (a-l), liquid-liquid (l-l), and solid-liquid (s-l) interfaces in the past decade. SALVI is one of the first microfluidics-based reactors that has enabled direct analysis of volatile liquids in vacuum surface tools such as scanning electron microscopy (SEM) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Its integration into ambient and vacuum spectroscopy and microscopy is illustrated. Several applications are highlighted including (1) imaging nanoparticles in liquid using in situ SEM; (2) mapping the evolving l-l interface using in situ x-ray absorption spectroscopy and ToF-SIMS; (3) following complex a-l interfacial oxidation reaction products using in situ ToF-SIMS; (4) capturing biological interfaces of cells and microbes via in vivo multimodal and correlative imaging; and (5) monitoring the dynamic solid electrode and liquid electrolyte interface using in operando molecular imaging. Finally, outlook and recommendations are presented. Besides showing the holistic information volume obtained by real-time multiplexed imaging, this review intends to convey the importance of tool development in revolutionizing surface and interface analysis using vacuum platforms previously limited to solid surfaces. Microfluidics is manifested to be not limited to ambient conditions in many examples in this review. Moreover, fundamental interfacial phenomena underpinning mass and charge transfer can now be pursued in real time via innovated chemical imaging and spectroscopy.

中文翻译：

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在真空中使用微流体对液体进行原位，体内和在操作成像与光谱学中

这篇综述简要概述了在液体真空界面（SALVI）上进行分析的真空兼容微流体反应器系统的开发及其在原位，体内和操作中的多种应用在过去十年中对液体表面以及气-液（a1），液-液（11）和固-液（s1）界面进行了成像。SALVI是首批基于微流控技术的反应器之一，能够在真空表面工具（如扫描电子显微镜（SEM）和飞行时间二次离子质谱（ToF-SIMS））中直接分析挥发性液体。说明了其在环境和真空光谱学以及显微镜中的集成。重点介绍了以下几种应用：（1）使用原位SEM在液体中对纳米颗粒进行成像；（2）使用原位X射线吸收光谱法和ToF-SIMS绘制演化的ll界面；（3）使用原位跟随复杂的界面氧化反应产物ToF-SIMS；（4）通过体内多模态和相关成像捕获细胞和微生物的生物学界面；和（5）监测动态固体电极和液体电解质界面使用在operando分子成像。最后，提出了展望和建议。除了显示通过实时多路复用成像获得的整体信息量外，本综述还旨在传达工具开发在使用以前仅限于固体表面的真空平台革新表面和界面分析方面的重要性。在这篇综述中的许多例子中，微流控技术都表现为不限于环境条件。此外，现在可以通过创新的化学成像和光谱技术实时追踪支撑质量和电荷转移的基本界面现象。