Inorganic layered crystals such as mica and graphite have been investigated as intriguing two-dimensional systems1-2. Molecules can be adsorbed onto the surface or intercalated into the interlayer nanospace of the layered crystals. The atomically flat, uniformly charged, and chemically modifiable surface of the layered crystals with defined crystalline structure are ideal model systems to confine the movement of the adsorbed molecules, align them, and organize them in controlled manner, resulting in various functions such as polarized emission.3 Further, intercalation of layered crystals with a large amount of solvent molecules leads to swelling4 or exfoliation5 of the crystal. After full exfoliation, inorganic nanosheets with the thickness of 1 nm are obtained. Because nanosheets are ultimately anisotropic functional nanoparticles with various function, they are applicable to fabricate advanced materials such as nanosheet/polymer composites,6 porous materials,7 liquid crystalline colloids,8-9 and bio/inorganic composites with DNA10 and motor-protein.11 In this lecture, some selected topics of our researches on inorganic layered crystals and nanosheets will be presented.
Miyamoto, N.; Yamamoto, S., Chapter 7: Functional Layered Compounds for Nanoarchitectonics. In Supramolecular Nanoarchitectonics, Ariga, K.; Aono, M., Eds. Elsevior: 2017; pp 173-192.
Miyamoto, N.; Ohsedo, Y.; Nakato, T., Chapter 8: Colloidal nanosheets. In Inorganic Nanosheets and Nanosheet-Based Materials, Nakato, T.; Kawamata, J.; Takagi, S., Eds. Springer Japan: Tokyo, 2017; pp 201-260.
Miyamoto, N.; Kuroda, K.; Ogawa, M., Uni-Directional Orientation of Cyanine Dye Aggregates on a K4Nb6O17 Single Crystal : Toward Novel Supramolecular Assemblies with Three-Dimensional Anisotropy. J. Am. Chem. Soc. 2001, 123, 6949-6950.
Geng, F.; Ma, R.; Nakamura, A.; Akatsuka, K.; Ebina, Y.; Yamauchi, Y.; Miyamoto, N.; Tateyama, Y.; Sasaki, T., Reversible, Instant, and Unusually Stable ~100-Fold Swelling of Inorganic Layered Materials. Nature Commun. 2013, 4: 1632.
Miyamoto, N.; Yamamoto, H.; Kaito, R.; Kuroda, K., Formation of extraordinarily large nanosheets from K4Nb6O17 crystals. Chem. Commun. 2002, 2378-2379.
Miyamoto, N.; Shintate, M.; Ikeda, S.; Hoshida, Y.; Yamauchi, Y.; Motokawa, R.; Annaka, M., Liquid Crystalline Inorganic Nanosheets for Facile Synthesis of Polymer Hydrogels with Anisotropies in Optical Property, Structure, Swelling/Deswelling, and Ion Transport/Fixation. Chem. Commun. 2013, 49, 1082-1084.
Bastakoti, B. P.; Li, Y.; Imura, M.; Miyamoto, N.; Nakato, T.; Sasaki, T.; Yamauchi, Y., Polymeric micelle assembly with inorganic nanosheets for construction of mesoporous architectures with crystallized walls. Angew. Chem. Int. Ed. 2015, 54 (14), 4222-5.
Miyamoto, N.; Nakato, T., Liquid crystalline nature of K4Nb6O17 nanosheet sols and their macroscopic alignment. Adv. Mater. 2002, 14 (18), 1267-1270.
Yamaguchi, D.; Miyamoto, N.; Fujita, T.; Nakato, T.; Koizumi, S.; Ohta, N.; Yagi, N.; Hashimoto, T., Aspect Ratio Dependent Phase Transitions and Concentration Fluctuations in Aqueous Colloidal Dispersions of Charged Plate-Like Particles. Phys. Rev. E. 2012, 85, 011403.
Yamguchi, N.; Anraku, S.; Paineau, E.; Safinya, C. R.; Davidson, P.; Michot, L. J.; Miyamoto, N., Swelling Inhibition of Liquid Crystalline Colloidal Montmorillonite and Beidellite Clays by DNA. Sci. Rep. 2018, 8 (4367).
Kato, R.; Kakugo, A.; Shikinaka, K.; Ohsedo, Y.; Kabir, A. M. R.; Miyamoto, N., Fusion of inorganic nanosheets and microtubules for active anisotropic colloid driven by biochemical energy and entropic force. ACS Omega 2018.