Solvent-driven self-assembly of amphiphilic block copolymers in emulsions for hierarchical particle design

The spatial organization of amphiphiles within emulsions offers a versatile route to constructing complex soft-matter architectures. Here, we present the solvent-dependent interfacial behavior of polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) copolymers in evaporative emulsions and its decisive role in dictating particle morphology. By systematically varying the solvent selectivity toward each block, we achieve precise control over the confined assembly of PS-b-P4VP, producing a continuous morphological evolution from nonporous spheres to porous particles, vesicles, and micellar structures. Enhanced affinity of solvents for the P4VP block promotes the polymer adsorption at the emulsion interface, triggering pronounced interfacial instabilities that drive hierarchical structure formation. Furthermore, variations in P4VP volume fraction and surfactant concentration modulate these interfacial dynamics, enabling a tunable library of well-defined polymer particles. This study establishes solvent selectivity as a powerful design parameter for manipulating interfacial self-assembly pathways of amphiphilic block copolymers, offering a robust and scalable strategy for engineering functional soft colloids.