Predicting excess solvation in binary solvents toward green organic semiconductor processing
Year: 2026
Type: preprint
Abstract: Replacing halogenated solvents in organic semiconductor inks benefits from binary mixtures that balance dissolution and film drying, yet mixing changes solvation beyond the pure-solvent contributions. Here, we introduce ShellEx, a three-dimensional contact-shell model distilled from openCOSMO-RS that predicts this endpoint-fixed excess solvation from force-field geometries. Trained on 10,640 calculated curves for aromatic cores resembling organic semiconductors, ShellEx reduces the error by 27% on held-out curves relative to a zero-excess reference, which interpolates linearly between pure-solvent free energies. On 148 measured curves of eight solutes, its error, averaged with equal weight per solute, is similar to that of openCOSMO-RS and below that of simpler baselines. An openCOSMO-RS map of 200 solvent pairs for 35 cores ranks limonene–γ-valerolactone first among six predefined candidate-green pairs, with a median 1.35-fold concentration gain over the zero-excess reference. ShellEx selects the same pair and reproduces the pair ranking with a Spearman correlation of 0.85. ShellEx thus offers a route to prioritize green binary solvent pairs and compositions for halogen-free organic semiconductor inks before experimental testing.
Source: ChemRxiv
Authors: Taeyoon Ki, Kwanghee Lee
Institution: Gwangju Institute of Science and Technology
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Award: G5832646036
OpenAlex ID: W7223185265