title: Unusually stable ~100-fold reversible and instantaneous swelling of inorganic layered materials.
abstract: Cells can swell or shrink in certain solutions; however, no equivalent activity has been observed in inorganic materials. Although lamellar materials exhibit increased volume with increase in the lamellar period, the interlamellar expansion is usually limited to a few nanometres, with a simultaneous partial or complete exfoliation into individual atomic layers. Here we demonstrate a large monolithic crystalline swelling of layered materials. The gallery spacing can be instantly increased ~100-fold in one direction to ~90 nm, with the neighbouring layers separated primarily by H2O. The layers remain strongly held without peeling or translational shifts, maintaining a nearly perfect three-dimensional lattice structure of >3,000 layers. First-principle calculations yield a long-range directional structuring of the H2O molecules that may help to stabilize the highly swollen structure. The crystals can also instantaneously shrink back to their original sizes. These findings provide a benchmark for understanding the exfoliating layered materials.
authors.affiliation: International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Ibaraki, Japan.
authors.forename: Fengxia
authors.initials: F
authors.lastname: Geng
authors.forename: Renzhi
authors.initials: R
authors.lastname: Ma
authors.forename: Akira
authors.initials: A
authors.lastname: Nakamura
authors.forename: Kosho
authors.initials: K
authors.lastname: Akatsuka
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Ebina
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Yamauchi
authors.forename: Nobuyoshi
authors.initials: N
authors.lastname: Miyamoto
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Tateyama
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Sasaki
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