title: Kinetics of the formation of 2D-hexagonal silica nanostructured materials by nonionic block copolymer templating in solution.
abstract: The different steps of the self-assembly in solution of several 2D-hexagonal silica nanostructured SBA-15 materials have been investigated by SAXS and SANS in situ experiments. Unique quantitative information about the shape and size evolution upon time of the micellar aggregates throughout the self-assembly process is obtained using a complete model that describes well the scattering data for the various synthesis conditions. In all cases, before the precipitation of the material, the micelles shape changes from spherical to rod-like, where the structure of the rod-like micelles is linked to the structure of the 2D-hexagonal precipitated material. In addition, the kinetics of hydrolysis of the inorganic precursor (TEOS) has been determined by in situ Raman spectroscopy. More specifically, by comparing synthesis made with different acids (HNO(3), HBr, HCl, H(2)SO(4), and H(3)PO(4)), it is found that materials prepared using the "salting-out" anions (SO(4)(2-) and H(2)PO(4)(-)) are much better ordered than with the "salting-in" anions (NO(3)(-) and Br(-)).
authors.affiliation: Laboratoire de Physique de Solides, UMR 8502, Bât. 510, Université Paris-Sud, F-91405 Orsay, France.
authors.forename: Sabine
authors.initials: S
authors.lastname: Manet
authors.forename: Julien
authors.initials: J
authors.lastname: Schmitt
authors.forename: Marianne
authors.initials: M
authors.lastname: Impéror-Clerc
authors.forename: Vladimir
authors.initials: V
authors.lastname: Zholobenko
authors.forename: Dominique
authors.initials: D
authors.lastname: Durand
authors.forename: Cristiano L P
authors.initials: CL
authors.lastname: Oliveira
authors.forename: Jan Skov
authors.initials: JS
authors.lastname: Pedersen
authors.forename: Christel
authors.initials: C
authors.lastname: Gervais
authors.forename: Niki
authors.initials: N
authors.lastname: Baccile
authors.forename: Florence
authors.initials: F
authors.lastname: Babonneau
authors.forename: Isabelle
authors.initials: I
authors.lastname: Grillo
authors.forename: Florian
authors.initials: F
authors.lastname: Meneau
authors.forename: Cyrille
authors.initials: C
authors.lastname: Rochas
mesh_terms: D000143:Acids / Q000737:chemistry; D006868:Hydrolysis; D007700:Kinetics; D008823:Micelles; D049329:Nanostructures / Q000737:chemistry*; D033363:Neutron Diffraction; D011060:Poloxalene / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D053838:Scattering, Small Angle; D012822:Silicon Dioxide / Q000737:chemistry*; D012996:Solutions / Q000737:chemistry; D013059:Spectrum Analysis, Raman; D014961:X-Ray Diffraction
chemical_list: D000143:Acids; D008823:Micelles; D011108:Polymers; C509969:SBA-15; D012996:Solutions; C464484:pluronic block copolymer P123; D012822:Silicon Dioxide; D011060:Poloxalene