American Chemical Society
nl2c01762_si_005.avi (15.45 MB)

In Situ TEM Observation of Stagnant Liquid Layer Activation in Nanochannel

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posted on 2022-08-29, 20:46 authored by Peng Xue, Mi Qu, Jie Shi, Youhong Jiang, Nana He, Tiqing Zhao, Shiwen Luo, Shiyuan Zhou, Jia-Jun Zhang, Yong Luo, Guangwen Chu, Hui Li, Jian-Feng Chen, Shi-Gang Sun, Hong-Gang Liao
The kinetics of mass transfer in a stagnant fluid layer next to an interface govern numerous dynamic reactions in diffusional micro/nanopores, such as catalysis, fuel cells, and chemical separation. However, the effect of the interplay between stagnant liquid and flowing fluid on the micro/nanoscopic mass transfer dynamics remains poorly understood. Here, by using liquid cell transmission electron microscopy (TEM), we directly tracked microfluid unit migration at the nanoscale. By tracking the trajectories, an unexpected mass transfer phenomenon in which fluid units in the stagnant liquid layer migrated two orders faster during gas–liquid interface updating was identified. Molecular dynamics (MD) simulations indicated that the chemical potential difference between nanoscale liquid layers led to convective flow, which greatly enhanced mass transfer on the surface. Our study opens up a pathway toward research on mass transfer in the surface liquid layers at high spatial and temporal resolutions.