title: Hierarchical architectures by synergy between dynamical template self-assembly and biomineralization.
abstract: Diatoms, shells, bones and teeth are exquisite examples of well-defined structures, arranged from nanometre to macroscopic length scale, produced by natural biomineralization using organic templates to control the growth of the inorganic phase. Although strategies mimicking Nature have partially succeeded in synthesizing human-designed bio-inorganic composite materials, our limited understanding of fundamental mechanisms has so far kept the level of hierarchical complexity found in biological organisms out of the chemists' reach. In this letter, we report on the synthesis of unprecedented double-walled silica nanotubes with monodisperse diameters that self-organize into highly ordered centimetre-sized fibres. A unique synergistic growth mechanism is elucidated by the combination of light and electron microscopy, synchrotron X-ray diffuse scattering and Raman spectroscopy. Following this growth mechanism, macroscopic bundles of nanotubules result from the kinetic cross-coupling of two molecular processes: a dynamical supramolecular self-assembly and a stabilizing silica mineralization. The feedback actions between the template growth and the inorganic deposition are driven by a mutual electrostatic neutralization. This 'dynamical template' concept can be further generalized as a rational preparation scheme for materials with well-defined multiscale architectures and also as a fundamental mechanism for growth processes in biological systems.
authors.affiliation: Groupe Matière Condensée et Matériaux, UMR 6626 CNRS et Université Rennes 1, 263 Avenue du général Leclerc, 35042 Rennes Cedex, France.
authors.forename: Emilie
authors.initials: E
authors.lastname: Pouget
authors.forename: Erik
authors.initials: E
authors.lastname: Dujardin
authors.forename: Annie
authors.initials: A
authors.lastname: Cavalier
authors.forename: Alain
authors.initials: A
authors.lastname: Moreac
authors.forename: Céline
authors.initials: C
authors.lastname: Valéry
authors.forename: Valérie
authors.initials: V
authors.lastname: Marchi-Artzner
authors.forename: Thomas
authors.initials: T
authors.lastname: Weiss
authors.forename: Anne
authors.initials: A
authors.lastname: Renault
authors.forename: Maité
authors.initials: M
authors.lastname: Paternostre
authors.forename: Franck
authors.initials: F
authors.lastname: Artzner
mesh_terms: D032701:Biomimetics; D003460:Crystallization; D007700:Kinetics; D046529:Microscopy, Electron, Transmission; D008956:Models, Chemical; D049329:Nanostructures; D036103:Nanotechnology / Q000379:methods*; D043942:Nanotubes / Q000737:chemistry; D010456:Peptides, Cyclic / Q000737:chemistry; D012542:Scattering, Radiation; D012822:Silicon Dioxide / Q000737:chemistry*; D013004:Somatostatin / Q000031:analogs & derivatives / Q000737:chemistry; D013059:Spectrum Analysis, Raman; D055672:Static Electricity; D014965:X-Rays
chemical_list: D010456:Peptides, Cyclic; C060347:lanreotide; D013004:Somatostatin; D012822:Silicon Dioxide