Formation and growth mechanism of natural nanotubes: Imogolites

Masion Armand, Levard Clément, Rose Jérôme, Doelsch Emmanuel, Thill Antoine, Borschneck Daniel, Bottero Jean Yves. 2009. Formation and growth mechanism of natural nanotubes: Imogolites. Geochimica et Cosmochimica Acta, 73 (13), suppl., Résumé, A844 Annual V.M. Goldschmidt Conference. 19, Davos, Suisse, 21 Juin 2009/26 Juin 2009.

Quartile : Q1, Sujet : GEOCHEMISTRY & GEOPHYSICS

Note générale : Emmanuel Doelsch est l'expert invité du Cirad pour la conférence

Résumé : A distinctive feature of certain volcanic soils is the presence of short range ordered aluminosilicates imogolite and allophanes. Due to their high surface area and reactivity, these nanosized phases are an important factor affecting soil dynamics (carbon sequestration, pollutant mobility...). The structure of imogolite is well established: nanotubes with a diameter of ca. 2 nm and several hundreds of nm in length consisting of a curved gibbsite layer with isolated Si tetrahedra inside the tube. However, very little is known about the formation mechanisms of these nanotubes. In the present study, we synthesized these phases and examined the systems from the initial mixing of the reagents to the final products using a variety of analytical techniques (XRD, TEM, EXAFS, NMR and SAXS). Our results demonstrate that the precursors of the nanotubes are not a circular structure but roof tile shaped particules with sizes up 5 nm and varying curvatures. These precursors assemble to form short nanotubes or doughnuts. The final products are obtained by end-to-end assembly of these short nanotubes.

Mots-clés Agrovoc : structure chimique, silicate

Mots-clés complémentaires : Nanotube

Classification Agris : P33 - Chimie et physique du sol
000 - Autres thèmes

Champ stratégique Cirad : Hors axes (2005-2013)

Auteurs et affiliations

• Masion Armand, CNRS (FRA)
• Levard Clément, CNRS (FRA)
• Rose Jérôme, CNRS (FRA)
• Doelsch Emmanuel, CIRAD-PERSYST-UPR Recyclage et risque (FRA) ORCID: 0000-0002-7478-4296
• Thill Antoine, CEA (FRA)
• Borschneck Daniel, CNRS (FRA)
• Bottero Jean Yves, CNRS (FRA)

Source : Cirad - Agritrop (https://agritrop.cirad.fr/549460/)

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