Fusion Assembly of Diblock Copolymer Nanoparticles at Liquid–Solid Interface

The fusion/fission of sterically stabilized block copolymer nano-objects has garnered significant attention due to its ability to create sophisticated nanostructures with various applications. However, the transformation of diblock copolymer nanoparticles into self-assembled membrane structures remains a formidable challenge in polymer self-assembly. Here, we introduce a serendipitous phenomenon─termed liquid–solid interfacial fusion assembly (LSIFA)─that enables the controlled formation of diblock copolymer membranes with tunable thicknesses at the liquid–solid interface. Kinetic studies show LSIFA process involves the adsorption of sterically stabilized diblock copolymer nanoparticles onto a porous particle surface in a liquid medium, followed by gradual fusion into a continuous diblock copolymer membrane. Factors such as electrostatic interactions, temperature, solvent choice, and copolymer composition are found to influence this process. LSIFA enables an unprecedented and generic fusion-driven assembly of block copolymer nanoparticles, offering new insights into copolymer assembly and providing a versatile and scalable approach for the construction of diverse functional composite materials.