Interfacial Fueling with Physical Autocatalysis Programs Transient Crystallization and Nonconventional Fluorescence

Abstract Chemically fueled self-assembly generates transient structures, but coupling spatially controlled product formation to phase evolution remains challenging, particularly for crystallization. Here we introduce a two-phase interfacial fueling strategy in which a hydrophobic anhydride fuel forms an oil phase and reacts with an aqueous precursor to generate amphiphiles locally at the oil–water interface. In the micelle-forming regime, the resulting assemblies enhance interfacial fuel transport and promote further amphiphile formation, establishing physical positive feedback. Coupling this process to ester hydrolysis enables transient micellar assembly. Decreasing product solubility redirects the same fueling network toward transient crystallization. In this regime, poly(sodium 4-styrenesulfonate) shifts the apparent crystallization boundary and regulates crystal growth and aggregation, with nuclear magnetic resonance titration and molecular simulations supporting polymer–amphiphile association. An alternative anionic polymer partially reproduces aggregation suppression, indicating that this behavior is not exclusive to a single polymer. Counterion-dependent fluorescence provides a label-free optical readout of transient crystallization. Across the tested anhydride–ester systems, these results establish a design framework linking fuel partitioning, product solubility, and intermolecular association to transient structural and optical responses. Extension to other chemical systems requires compatible phase behavior and a suitable balance between product-generation and deactivation kinetics.