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Updated: Jan 3, 2026
Revealing Dynamic Processes of Materials in Liquids Using Liquid Cell Transmission Electron Microscopy
Published on: December 20, 2012
In Situ Transmission Electron Microscope Liquid Cell 3D Profile Reconstruction and Analysis of Nanoscale Liquid Water
Guanglei Chen1, Haim H Bau2, Calvin H Li1
1Department of Mechanical Engineering , Villanova University , Villanova , Pennsylvania 19085 , United States.
Abstract:
Static nanodroplets and dynamic contact line (CL) movements were visualized by an in situ transmission electron microscope (TEM) liquid cell technique at nanometer spatial resolution. Crawling and sliding movements of nanoscale CL were observed. The crawling happened at a capillary number (Ca) range of ∼10-9 to ∼10-8, and the sliding happened at a Ca range of ∼10-8 to ∼10-7. Three dimensional (3D) image construction had been employed to study static and dynamic contact angles (CAs) at nanoscale. CA hysteresis at nanoscale was observed in the sliding but not in the crawling. The energies associated with sliding were analyzed to investigate the CA hysteresis. An empirical model of the relationship between nanoscale CAs and Ca was developed. Both the experimental observation and the empirical analysis suggested that the competition among substrate defect, CL elastic, and molecular activation energies dictated different CL movements at nanoscale.
