Molecular‐Interactions Driven Conjugated Polymer Nanofiber Self‐Assembly Toward Greener Fabrication

Self-assembled conjugated polymer (CP) nanofibers form elongated, percolated networks that facilitate efficient charge transport and mechanical compliance, yet a general strategy for their formation from solution remains elusive. Here, we present a molecular-interaction-governed framework for antisolvent-induced nanofiber self-assembly that couples thermodynamic fibrillar preaggregate formation with kinetic nanofiber growth. The framework integrates Hansen solubility parameters with a segment-specific affinity descriptor to predict solvent-antisolvent combinations for nanofiber formation. Structural characterization combined with molecular modeling shows that antisolvents with low affinity for alkyl side chains promote rigid, elongated fibrillar preaggregates, acting as key intermediates in nanofiber formation. This framework is validated across diverse solvent-antisolvent combinations and polymer systems, yielding nanofibers with tunable widths of 50-200 nm. It further enables the identification of eco-friendly, terpene-based solvent systems for green nanofiber manufacturing, while achieving up to threefold enhancements in field-effect mobility. Together, these advances provide a pathway to rationally control CP nanostructures, offering broad utility for advancing sustainable, stretchable electronics.