Real-time observation of dynamic structure of liquid-vapor interface at nanometer resolution in electron irradiated sodium chloride crystals

Abstract

Gang Ren 1 ✉ the dynamics and structure of the liquid and vapor interface has remained elusive for decades due to the lack of an effective tool for directly visualization beyond micrometer resolution. Here, we designed a simple liquid-cell for encapsulating the liquid state of sodium for transmission electron microscopic (TEM) observation. The real-time dynamic structure of the liquid-vapor interface was imaged and videoed by TEM on the sample of electron irradiated sodium chloride (NaCl) crystals, a well-studied sample with low melting temperature and quantum super-shells of clusters. The nanometer resolution images exhibit the fine structures of the capillary waves, composed of first-time observed three zones of structures and features, i.e. flexible nanoscale fibers, nanoparticles/clusters, and a low-pressure area that sucks the nanoparticles from the liquid to the interface. Although the phenomenons were observed based on irradiated NaCl crystals, the similarities of the phenomenons to predictions suggest our real-time ovserved dynamic structure might be useful in validating long-debated theoretical models of the liquid-vapor interface, and enhancing our knowledge in understanding the non-equilibrium thermodynamics of the liquid-vapor interface to benefit future engineering designs in microfluidics.

Unhindered Brownian Motion of Individual Nanoparticles in Liquid-Phase Scanning Transmission Electron Microscopy

“…Numerous LPTEM studies have investigated the motion of NPs, but the NPs chosen for study were likely interacting with the enclosing liquid cell membranes: All previous LPTEM studies ,,,− have found diffusive motion of NPs exceptionally slower than that of unhindered and passive diffusion. Even when Chee et alconsidered only the fastest motion observed, the instantaneous diffusion coefficients were still 20 times smaller than predictions for bulk conditions .…”

Single-molecule 3D imaging of HIV cellular entry by liquid-phase electron tomography

“…The to sandwich the biological samples follows the protocol that has been used to examine the real-time dynamic structures of liquid-vapor interfaces of liquid sodium. 42 In brief, ~0.2 μl of sample solution (native liquid state, label-free, without any staining) was deposited and then sandwiched between two layers of 300-mesh TEM Formvar-coated copper grids (~3 mm in diameter, ~100 µm in window diameter) at room temperature with a humidity level of ~80%. The sandwiched grids were compressed together under a pressure of ~8 psi (~0.55 bar) for ~20 seconds.…”

“…To image the sample in liquid-phase state easily, we recently reported a simple method 42 in which two plastic Formvar lms were used to encapsulate a liquid sample. By this method, we imaged for rst-time the dynamic structure of the liquid-vapor interface at ~1 nm resolution for over one hour period 42 .…”

“…To image the sample in liquid-phase state easily, we recently reported a simple method 42 in which two plastic Formvar lms were used to encapsulate a liquid sample. By this method, we imaged for rst-time the dynamic structure of the liquid-vapor interface at ~1 nm resolution for over one hour period 42 . Here, we implemented this simple designed method to study the viral entry process via imaging the intermediate states of HIV viral entry to HeLa cells in a liquid-phase state.…”

Transport and Interfacial Properties of Mixed Molten Carbonate/Hydroxide Electrolytes by Molecular Dynamics Simulations

“…Also, in the presence of hydroxide (smaller/harder) anions in the electrolyte, the smaller (harder) cation, Li + , is more favored at the interface than is a larger cation, Na + or K + . Experimental probing of these system using electron microscopy 44 would be necessary to verify the observed interfacial structures. We believe that these simulation results will guide future experimental studies into the complex nature of molten carbonates, and can also aid in the development of molten carbonate fuel cell electrolytes.…”