Elucidating Structural and Electronic Features of\nPEO/(101)-TiO<sub>2</sub> Anatase Interfaces through First-Principles\nMetadynamics Simulations

Structural\nand dynamic properties of the poly(ethylene oxide)/anatase\ninterface (<i>i.e.</i>, PEO/TiO<sub>2</sub>) are explored <i>via</i> metadynamics simulations and density functional tight\nbinding. 1-ns trajectories are reconstructed upon two different structure-related\ncollective variables: interfacial Ti<sub>surf</sub>–O<sub>PEO</sub> distances and polymer chain torsion angles. The conformational freedom\nof PEO is significantly influenced by multiple favorable interactions\nwith unsaturated Ti sites on the anatase surface. From these trajectories,\nseveral equilibrium structures extracted from the free-energy surface\nare analyzed using electronic structure calculations within density\nfunctional theory: the titania work function results in being largely\ninfluenced by the dynamically resolved structuring of PEO on the anatase\nsurface. Besides the intrinsic valuable insights into the technologically\nrelevant PEO/TiO<sub>2</sub> interface, our findings provide the first\ninnovative example of an affordable yet reliable computational protocol\nto describe a heterogeneous interface and predict the effects of molecular\ndynamics on relevant physicochemical properties.