title: Biomimetic dual templating of silica by polysaccharide/protein assemblies.
abstract: The control of silica growth by living organisms such as diatoms is known to involve the templating effect of several biomolecules working concomitantly. However, until now, biomimetic studies involving model molecules have mainly been performed with single templates. We show here that the addition of two biopolymers, gelatin and alginic acid, to silicate solutions allows the formation of complex structures resulting from the combined templating effect of both components at different scales. Gelatin is able to activate silica formation resulting in hybrid aggregates at the nanoscale. Alginic acid does not interfere with silica condensation but is able to control silica morphology through the assembly of these gelatin-silica aggregates at the microscale. For all materials, calcination up to 700 degrees C degrades the polymer component of the hybrid material and opens macroporosity in the silica network. In parallel, the high thermal stability of gelatin allows a good preservation of initial silica nanoparticle size upon heating whereas a coarsening process is observed in the sole presence of alginate. These results correlate well with previous models of biosilicification and suggest that the use of multiple templates is a suitable approach to elaborate more complex silica architectures.
authors.affiliation: UPMC Univ Paris 6, UMR 7574, Chimie de la Matière Condensée de Paris, F-75005 Paris, France.
authors.forename: Clémentine
authors.initials: C
authors.lastname: Gautier
authors.forename: Nora
authors.initials: N
authors.lastname: Abdoul-Aribi
authors.forename: Cécile
authors.initials: C
authors.lastname: Roux
authors.forename: Pascal J
authors.initials: PJ
authors.lastname: Lopez
authors.forename: Jacques
authors.initials: J
authors.lastname: Livage
authors.forename: Thibaud
authors.initials: T
authors.lastname: Coradin
mesh_terms: D000464:Alginates / Q000737:chemistry / Q000378:metabolism*; D032701:Biomimetics; D011232:Chemical Precipitation; D005780:Gelatin / Q000737:chemistry / Q000378:metabolism*; D020723:Glucuronic Acid / Q000737:chemistry / Q000378:metabolism; D006603:Hexuronic Acids / Q000737:chemistry / Q000378:metabolism; D046911:Macromolecular Substances / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D008954:Models, Biological; D012822:Silicon Dioxide / Q000378:metabolism*
chemical_list: D000464:Alginates; D006603:Hexuronic Acids; D046911:Macromolecular Substances; D012822:Silicon Dioxide; D020723:Glucuronic Acid; D005780:Gelatin