2026-03-11 九州大学
固体表面の高分子鎖の分子運動を実空間で可視化し、新たな分子描像を見出した。（左上段）AFM高さ像、（右上段）模式図、（下段）（1）熱活性、（2）熱抑制、（3）吸脱着を伴う非平衡挙動の模式図。
＜関連情報＞
- https://www.kyushu-u.ac.jp/ja/researches/view/1424
- https://www.kyushu-u.ac.jp/f/65007/26_0311_01.pdf
- https://pubs.acs.org/doi/10.1021/jacs.5c23137
固体表面上の孤立高分子鎖におけるセグメント状ダイナミクスの直接可視化 Direct Visualization of Segment-Like Dynamics in Isolated Polymer Chains on Solid Surfaces
Shuji Morita,Yuma Morimitsu,Shiho Tanizaki,Tomohiro Kubo,Satoru Yamamoto,Kotaro Satoh,and Keiji Tanaka
Journal of the American Chemical Society Published: March 11, 2026
DOI:https://doi.org/10.1021/jacs.5c23137
Abstract
The performance of polymer-based composites, coatings, and adhesives is critically governed by the dynamics of chains at solid interfaces, yet their molecular principles remain unresolved. Here, we use time-resolved atomic force microscopy to directly map segment-level relaxation dynamics in isolated polystyrene chains on atomically flat substrates. We uncover pronounced spatial heterogeneity, with some segments accelerating with temperature while others slowing down, a counterintuitive behavior arising from transient adsorption. These dynamics propagate into neighboring chains through interfacial coupling and extend the influence of adsorption beyond direct contacts. Molecular dynamics simulations corroborate the coexistence of thermally activated and adsorption-driven slowing processes, and experiments on catechol-functionalized chains demonstrate generality and relevance to adhesion on metal oxides. Our results establish a real-space framework for linking interfacial structure and chain dynamics. They also reveal isolated chains on solids as nonequilibrium systems, offering a paradigm for molecular-level design of adhesion and interfacial toughness.
