title: One-step exfoliation of kaolinites and their transformation into nanoscrolls.
abstract: Kaolinite nanoscrolls, rolled kaolinite sheets with a tubular form, were prepared by a one-step route in which intercalation of guest species and swelling with solvent proceed at the same time. A methoxy-modified kaolinite was exfoliated by the intercalation of hexadecyltrimethylammonium chloride. The formation of nanoscrolls by the one-step route proceeded only by several alkyltrimethylammonium salts and 1-hexadecyl-3-methylimidazolium chloride. Intercalation of primary amines caused the formation of nanoscrolls by a two-step route in which the intercalation and swelling proceed separately. The successful one-step route is ascribed to the relatively weak interactions between the head groups of guest species and the interlayer surface of methoxy-modified kaolinite, and the interaction is thought to allow the formation of a flexible array of interlayer guest species for swelling. The tubular structure was mostly retained after the heat treatment at 600 °C to form hierarchically porous aluminosilicates with amorphous frameworks. The nanoscrolls intercalated organic guests species, which are not directly intercalated into methoxy-modified kaolinite, between the scrolled layers. The formation route to nanoscrolls is quite dependent not only on the surface modification of kaolinite but also on the structure of guest species.
authors.affiliation: Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Kuroda
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Ito
authors.forename: Kenichi
authors.initials: K
authors.lastname: Itabashi
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Kuroda