title: Synthesis and crystal structures of a novel layered silicate SSA-1 and its microporous derivatives by topotactic transformation.
abstract: The synthesis of a novel layered silicate SSA-1 (SSA: silicate synthesized with a quaternary amine) was achieved in the SiO2-H2O-TEAOH (TEAOH: tetraethylammonium hydroxide - as an organic structural directing agent) system. The crystal structure of SSA-1 involved two silicate layers composed of bre [10T]-type CBU (Composite Building Unit) and TEAOH in interlayers. The topotactic transformation of SSA-1 by calcination was examined, resulting in a porous material (PML-1: porous material transformed from a layered silicate) with a 108 m2g-1BET surface area and 0.035 cm3g-1pore volume. PML-1 is a siliceous microporous material with silanols in the framework and possesses unique properties, such as hydrophilicity, in spite of all its silica composition. The most reasonable crystal structure of PML-1 was successfully determined on the basis of the crystal structure of SSA-1 by a combination of manual modelling, PXRD pattern simulation, DFT optimization and Rietveld analysis. Additionally, an interlayer expanded siliceous zeolite SSA-1 (IEZ-SSA-1) was also successfully prepared by silylation using trichloro(methyl)silane under acidic conditions. IEZ-SSA-1 showed hydrophilicity or hydrophobicity properties by changing the functional group of the pillar part in the interlayer. Additionally, IEZ-SSA-1 showed a large gas adsorption property (537 m2g-1and 0.21 cm3g-1).
authors.affiliation: Graduate School of Engineering, Gifu University, Yanagido 1-1, Gifu, 501-1193, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Takahashi
authors.affiliation: Graduate School of Engineering, Gifu University, Yanagido 1-1, Gifu, 501-1193, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Kurita
authors.affiliation: National Institute of Advanced industrial and Technology (AIST) Tohoku, 4-2-1, Nigatake, Miyagino-ku, Sendai, 983-8551, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Ikeda
authors.affiliation: Faculty of Engineering, Gifu University, Yanagido 1-1, Gifu, 501-1193, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Miyamoto
authors.affiliation: Faculty of Engineering, Gifu University, Yanagido 1-1, Gifu, 501-1193, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Uemiya
authors.affiliation: Life Science Research Center, Gifu University, Yanagido 1-1, Gifu, 501-1193, Japan.
authors.forename: Y
authors.identifier: http://orcid.org/0000-0001-9987-0417
authors.initials: Y
authors.lastname: Oumi