2026-05-20 九州大学
すべりと表面形状を同時にマッピングする新規原子間力顕微鏡法。
＜関連情報＞
- https://www.kyushu-u.ac.jp/ja/researches/view/1480
- https://pubs.acs.org/doi/10.1021/acs.nanolett.6c01403
疎水性は水の滑りに影響を与えない：滑り長さマッピングからの知見 Hydrophobicity Does Not Affect Water Slip: Insights from Slip Length Mapping
Haruya Ishida,Koji Takahashi,Vishwanath Ganesan,Nenad Miljkovic,and Hideaki Teshima
Nano Letters Published: May 15, 202
DOI:https://doi.org/10.1021/acs.nanolett.6c01403
Abstract
While slip at solid–water interfaces has attracted broad interest, slip lengths reported in experiments─especially on hydrophobic surfaces (i.e., contact angles >90°)─vary widely due to surface topographical and chemical heterogeneity, hindering quantitative understanding of the true slip length. Using highly sensitive frequency-modulation atomic force microscopy, we achieved simultaneous nanoscale mapping of slip length and surface topography, with a 159-fold improvement in slip length detection sensitivity. True slip lengths measured on flat regions of various substrates were found to be almost zero, following a scaling rule predicted by molecular dynamics simulations. As the only exception, a large slip length of 43.2 ± 5.8 nm was measured on graphite in deionized water, but it vanished upon immersion in electrolyte solutions. This unique behavior was rationalized by graphite’s atomic-scale smoothness, chemical homogeneity, and ion adsorption. Our method experimentally advances a unified picture of fluid slip.
