Hierarchical Nanostructures Constructed by Soft Epitaxial Self-Assembly of Organic-Inorganic Hybrid Giant Amphiphiles.

Abstract

2D nanomaterials with ångström-scale thicknesses offer a unique platform for confining molecules at an unprecedentedly small scale, presenting novel opportunities for modulating material properties and probing microscopic phenomena. In this study, mesogen-tethered polyhedral oligomeric silsesquioxane (POSS) amphiphiles with varying numbers of mesogenic tails to systematically influence molecular self-assembly and the architecture of the ensuing supramolecular structures, are synthesized. These organic-inorganic hybrid amphiphiles facilitate precise spatial arrangement and directional alignment of the primary molecular units within highly ordered supramolecular structures. The correlation between molecular design and the formation of superlattices through comprehensive structural analyses, incorporating molecular thermodynamics and kinetics, is explored. The distinct intermolecular interactions of the POSS core and the mesogenic tails drive the preferential formation of a 2D inorganic sublattice while simultaneously guiding the hierarchical assembly of organic lamellae via soft epitaxy. The findings reveal the intricate balance between shape, size, and interaction strengths of the inorganic and organic components, and how these factors collectively influence the structural hierarchy of the superstructures, which consist of multiple sublattices. By controlling this unique molecular behavior, it is possible to modulate or maximize the anisotropy of optical, mechanical, and electrical properties at the sub-nanometer scale for nanotechnology applications.