title: Co-development of crystalline and mesoscopic order in mesostructured zeolite nanosheets.
abstract: Mesoporous zeolites are a new and technologically important class of materials that exhibit improved diffusion and catalytic reaction properties compared to conventional zeolites with sub-nanometer pore dimensions. During their syntheses, the transient developments of crystalline and mesoscopic order are closely coupled and challenging to control. Correlated solid-state NMR, X-ray, and electron microscopy analyses yield new molecular-level insights on the interactions and distributions of complicated organic structure-directing agents with respect to crystallizing zeolite frameworks. The analyses reveal the formation of an intermediate layered silicate phase, which subsequently transforms into zeolite nanosheets with uniform nano- and mesoscale porosities. Such materials result from coupled surfactant self-assembly and inorganic crystallization processes, the interplay between which governs the onset and development of framework structural order on different length and time scales.
authors.affiliation: Department of Chemical Engineering, University of California, Santa Barbara, CA 93106 (USA).
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Messinger
authors.forename: Kyungsu
authors.initials: K
authors.lastname: Na
authors.forename: Yongbeom
authors.initials: Y
authors.lastname: Seo
authors.forename: Ryong
authors.initials: R
authors.lastname: Ryoo
authors.forename: Bradley F
authors.initials: BF
authors.lastname: Chmelka
keywords: crystallization; layered silicates; mesostructured zeolites; self-assembly; solid-state NMR spectroscopy