Rational design of multicomponent nanocomposites toward hierarchical assemblies with design flexibility and structural fidelity*

Current successes on directed self-assembly heavily rely on precision in building block design, composition, and pair interactions. These requirements impose inherent limitations to developing materials beyond nanoscale. In contrast,  biological blends and high-entropy alloys can readily accommodate composition variations while still achieving their intended structures. We hypothesize that diversified chemical complexity and increased composition variety are the key principles for the unique phase behavior. The entropic energy gains will enhance inter-phase miscibility, weaken the dependence on specific pair interactions and enable long-range cooperativity. The hypothesis is validated in complex blends containing small molecules, block copolymer-based supramolecules, and nanoparticles. We obtained hierarchically structured composites with formulation flexibility in the filler size selection and blend composition. Each component is distributed to locally mediate unfavorable interactions, cooperatively mitigate composition fluctuations, and retain structural fidelity. These systematic studies provided a viable pathway to release multiple constraints in the composite design, developed processing conditions to access structural control beyond nanoscale, and demonstrated an entropy-driven behavior in organic/inorganic composites.