A workflow for molecular dynamics simulation of casting polymer film formation

Solvent evaporation during casting critically influences the structure and properties of polymeric films; however, atomistic-level simulations remain challenging owing to the multiscale nature of the process. Here, we present an iterative molecular dynamics (MD) workflow that reproduces the progressive drying of polymer solutions, enabling the detailed observation of structural reorganization. This method integrates automated solvent removal cycles with intermediate equilibration stages, mimicking the gradual densification observed experimentally. A poly(vinyl alcohol) (PVA)–quercetin system was used to validate this approach. Structural metrics, including root mean square deviation (RMSD), radius of gyration, density profiles, and radial distribution functions (RDFs), were monitored to capture morphological evolution. The results revealed stepwise compaction events synchronized with solvent-removal stages, leading to a reduction in the polymer radius of gyration, elimination of solvent-rich voids, and formation of a dense, homogeneous film. The final configurations exhibited extensive chain entanglement and localized clustering of quercetin, consistent with the experimental observations for the solvent- cast films. The workflow provides an adaptable, computationally efficient framework for simulating evaporation-driven film formation and offers predictive capability for tailoring the film structure through solvent type, evaporation kinetics, and composition. This approach can be readily extended to diverse polymer–solvent systems and supports the rational design of functional polymer coatings and membranes.