title: In Situ Small-Angle X-ray Scattering Investigation of the Formation of Dual-Mesoporous Materials.
abstract: The formation of a 2D-hexagonal (p6m) silica-based hybrid dual-mesoporous material is investigated in situ by using synchrotron time-resolved small-angle X-ray scattering (SAXS). The material is synthesized from a mixed micellar solution of a nonionic fluorinated surfactant, R(F) 8 (EO)9 (EO=ethylene oxide) and a nonionic triblock copolymer, P123. Both mesoporous networks, with pore dimensions of 3.3 and 8.5 nm respectively, are observed by nitrogen sorption, transmission electron microscopy (TEM), and SAXS. The in situ SAXS experiments reveal that mesophase formation occurs in two steps. First the nucleation and growth of a primary 2D-hexagonal network (N1), associated with mixed micelles containing P123, then subsequent formation of a second network (N2), associated with micelles of pure R(F) 8 (EO)9 . The data obtained from SAXS and TEM suggest that the N1 network is used as a nucleation center for the formation of the N2 network, which would result in the formation of a grain with two mesopore sizes. Understanding the mechanism of the formation of such materials is an important step towards the synthesis of more-complex materials by fine tuning the porosity.
authors.affiliation: Physical Chemistry, Lund University, P.O. Box 124, SE-221 00, Lund, Sweden. julien.schmitt@fkem1.lu.se.
authors.forename: Julien
authors.initials: J
authors.lastname: Schmitt
authors.affiliation: Université de Lorraine, UMR CNRS 7565 SRSMC, 54506, Vandoeuvre les Nancy cedex, France.
authors.forename: Nadia
authors.initials: N
authors.lastname: Canilho
authors.affiliation: Laboratoire de Physique de Solides, UMR CNRS 8502, Bât. 510, Université Paris-Sud, F-91405, Orsay, France.
authors.forename: Marianne
authors.initials: M
authors.lastname: Impéror-Clerc
authors.affiliation: Université de Lorraine, UMR CNRS 7565 SRSMC, 54506, Vandoeuvre les Nancy cedex, France.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Blin
authors.affiliation: Department of Chemistry and Interdisciplinary Nanoscience Center (iNANO), Aarhus University Gustav Wieds Vej 14, 8000, Aarhus C, Denmark.
authors.forename: Jan Skov
authors.initials: JS
authors.lastname: Pedersen
authors.affiliation: Beamline SWING, Synchrotron Soleil, BP 48, F-91192, Gif-sur-Yvette, France.
authors.forename: Javier
authors.initials: J
authors.lastname: Pérez
authors.affiliation: Université de Haute Alsace, Institut de Science des Matériaux de Mulhouse (IS2 M), Equipe Matériaux à Porosité Contrôlée (MPC), UMR CNRS 7361, F-68093, Mulhouse cedex, France.
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Lebeau
authors.affiliation: Université de Haute Alsace, Institut de Science des Matériaux de Mulhouse (IS2 M), Equipe Matériaux à Porosité Contrôlée (MPC), UMR CNRS 7361, F-68093, Mulhouse cedex, France.
authors.forename: Loic
authors.initials: L
authors.lastname: Vidal
authors.affiliation: Université de Lorraine, UMR CNRS 7565 SRSMC, 54506, Vandoeuvre les Nancy cedex, France.
authors.forename: Marie-José
authors.initials: MJ
authors.lastname: Stébé
keywords: electron microscopy; kinetics; mesoporous materials; small-angle X-ray scattering; surfactants