Encapsulation of inorganic nanoparticles into block copolymer micellar aggregates: Strategies and precise localization of nanoparticles

Precise assembly and localization of preformed inorganic nanoparticles (NPs) in block copolymer (BCP) assemblies are of great importance in realizing the formation of nano-hybrids with high performance. Properties of the nanocomposites depend not only on those of individual building blocks but also on their spatial organization at different length scales, demonstrating unique optical, electrical, and magnetic properties. With the aid of the BCPs, NPs can form a broader range of structures in the nanoscopically confined geometry. Thus, many studies have focused on the selective localization of NPs in BCP aggregates. In this paper, we will outline recent advances in the preparation strategies for precise localization of inorganic NPs into BCP micelles, including co-precipitation, supramolecular assembly, interfacial instabilities of emulsion droplets, heating–cooling, electrostatic interaction, and others. Manipulating the balance between enthalpic and entropic contributions provides one of the opportunities to precisely control the spatial distribution of NPs in BCPs assemblies. We will focus on the principles of precise control of dispersion and localization of the NPs in BCP micelles. Potential applications of the hybrid micelles will finally be discussed, followed by the summary and outlook of this emerging area.