Monodisperse nanosheet mesophases

• Published in: Science advances Vol. 10; no. 23; p. eadk6452
• Main Authors: Miyamoto, Nobuyoshi, Miyoshi, Momoka, Kato, Riki, Nakashima, Yuji, Iwano, Hiroyuki, Kato, Takashi
• Format: Journal Article
• Language: English
• Published: United States American Association for the Advancement of Science 07.06.2024
• Subjects: Materials Science; Physical and Materials Sciences; SciAdv r-articles
• ISSN: 2375-2548; 2375-2548
• DOI: 10.1126/sciadv.adk6452

Self-assemblies of anisotropic colloidal particles into colloidal liquid crystals and well-defined superlattices are of great interest for hierarchical nanofabrications that are applicable for various functional materials. Inorganic nanosheets obtained by exfoliation of layered crystals have been highlighted as the intriguing colloidal units; however, the size polydispersity of the nanosheets has been preventing precise design of the assembled structures and their functions. Here, we demonstrate that the anionic titanate nanosheets with monodisperse size reversibly form very unusual superstructured mesophases through finely tunable weak attractive interactions between the nanosheets. Transmission electron microscopy, polarizing optical microscopy, small-angle x-ray scattering, and confocal laser scanning microscopy clarified the reversible formation of the mesophases (columnar nanofibers, columnar nematic liquid crystals, and columnar nanofiber bundles) as controlled by counter cations, nanosheet concentration, solvent, and temperature. Size-regulated inorganic nanosheets were assembled into unusual columnar nanofibers and superstructured mesophases.