The Janus particles of two compositions or properties distinctly compartmentalized have important applications in stabilizing emulsion, drug carriers, interfacial catalysis, and building superstructures. Especially, the Janus nanoparticles of block copolymers with covalently linked compartments are strong in structure, and have attracted growing interests due to their nano-size, the flexible structures, and the response to solvent, pH value, temperature or other stimuli. It is important to develop new methods for a large-scale synthesis of Janus nanoparticles with tunable morphology, structure and chemical composition. This review summarizes the recent progress in the preparation of block copolymer Janus nanoparticles. Some important methods are discussed and compared in detail, which is conducive to the design and the preparation of the Janus nanoparticles for potential applications.

Janus particles  /  nanomaterials  /  block copolymers  /  self-assembly