Monomicelle-Encapsulated Nanocrystals as Versatile Building Blocks for Hydrogen-Bonded Superlattices with Enhanced Mechanical Properties.

We present a general strategy for constructing mechanically robust superlattices using monomicelle-encapsulated nanocrystals (MENCs) as building blocks. MENCs are created by encapsulating individual nanocrystals within micelles of poly(styrene-co-maleic anhydride), driven by hydrophobic interactions between styrene segments and native surface ligands. Concurrent hydrolysis of maleic anhydride moieties generates carboxyl groups that establish intramicelle hydrogen bonds (H-bonds), stabilizing MENCs in aqueous dispersion. Upon solvent evaporation, MENCs self-assemble into long-range-ordered, three-dimensional superlattices. Crucially, postassembly intermicelle H-bonding spontaneously fuses adjacent MENCs into a continuous, cross-linked architecture. This dual-level H-bonding imparts exceptional structural cohesion, yielding superlattices with elastic moduli of up to 18.73 GPa, far exceeding conventional superlattices stabilized by van der Waals or H-bonding interactions.