This paper presents an all-atom molecular dynamics (MD) simulation of highly charged and densely grafted polyelectrolyte (PE) brushes on a flat surface. Simulation findings for the variation of brush height with polymer size and grafting density are explained by the scaling laws for brushes in the non-linear osmotic regime. More importantly, this study establishes the triggering of an ultraconfinement effect by the densely grafted brushes. This effect leads to significant changes in the distribution, structure, and properties as well as a massive mobility reduction of both the counterions and water. Furthermore, the interplay of the ultraconfinement effect and the large counterion-PE electrostatic interactions trigger a “water-in-salt”-like scenario (witnessed in highly concentrated aqueous electrolyte solutions), which is characterized by the counterion-PE-functional group serving as the “salt” with the “salt” overwhelming the water in both mass and volume and affecting the solvation structure of the counterions by replacing the solvation water with the PE-functional group.

本文介绍了在平坦表面上带高电荷和紧密接枝的聚电解质（PE）刷子的全原子分子动力学（MD）模拟。刷子高度随聚合物尺寸和接枝密度变化的模拟结果可通过非线性渗透条件下刷子的比例定律来解释。更重要的是，这项研究建立了由密集嫁接的刷子引发的超限制作用。这种作用会导致分布，结构和性质发生重大变化，以及平衡离子和水的迁移率大大降低。此外，超限作用与巨大的抗衡离子-PE静电相互作用的相互作用触发了类似“盐包水”的情况（见证了高浓度电解质水溶液），