Unveiling crystallization-driven assembly in semicrystalline block copolymers using liquid-phase transmission electron microscopy

Abstract

The self-assembly of amphiphilic block copolymers (BCPs) provides a versatile route to programmable soft-matter architectures; however, the dynamics linking unimers to complex morphologies remain opaque. Using liquid-phase transmission electron microscopy (LP-TEM), we directly track semicrystalline BCPs in aqueous media and quantify their motion and transformations in real time. We observe stepwise lateral association of elemental micelles into cylindrical micelles and ring closure into toroids, governed by core crystallinity and interfacial curvature at the core–corona interface. Particle-tracking analyses reveal anomalous diffusion with transient superdiffusive bursts preceding assembly and long-range hydrophobic interactions that mediate micelle approach and assembly. These results establish a microscopy-based framework that connects crystallization-driven assembly with nonequilibrium pathway selection, enabling the rational control of hierarchical soft-matter nanostructures.