Mapping the Morphological Landscape of Dry Hydrophilic Brushes

Polymer brushes, densely grafted polymer chains tethered to solid surfaces, exhibit tunable physicochemical properties. While their behavior in solvated systems is well studied, the structural characteristics of dry polymer brushes remain less explored, despite their relevance to many applications, including sensing, gas separation, or dry adhesion. Here, we employ coarse-grained molecular dynamics simulations to investigate the morphology of dry poly(ethylene oxide) brushes across a range of chain lengths and grafting densities. A phase diagram constructed from 86 simulation systems reveals three distinct conformational regimes: “mushroom,” “crossover,” and “brush”. We characterize these regimes by analyzing cluster formation, polymer layer thickness, and the number of chains per aggregate. Overall, our findings uncover previously unexplored structural complexity within the “crossover” region, where intermediate morphologies appear, which may inform the rational design of advanced materials for sensing, separation, and environmental remediation.