Liquid–Solid Interfacial Fusion Assembly Enables the Precision Fabrication of Block Copolymer Vesicles

Abstract The self‐assembly of amphiphilic block copolymers in bulk or solution can lead to the formation of vesicles (polymersomes), which have a wide range of applications, including gene therapy, nanoreactors, and biosensing. Unfortunately, traditional self‐assembly methods for producing these nanostructures often face challenges in terms of complexity, time efficiency, and structural control. Here we show a versatile and scalable approach, termed liquid–solid interfacial fusion assembly (LSIFA), for the synthesis of monodisperse block copolymer vesicles with tunable composition, size, morphology, and permeability. As revealed by kinetic studies, LSIFA involves gradual fusion assembly of block copolymer spheres adsorbed at liquid–solid interface. Systematic analyses identify key factors governing LSIFA and confirm its universality. Conventional self‐assembly requires diblock copolymers with specific packing parameters to form vesicles. LSIFA overcomes this limitation, enabling precise fabrication of a wide range of well‐defined vesicles—a significant advance with enormous potential for applications in drug delivery, materials science, and beyond.