Composite nanoparticles: A new way to siliceous materials and a model of biosilica synthesis

• Published in: Materials chemistry and physics 2015-09, Vol.165, p.227-234
• Main Authors: Annenkov, Vadim V., Pal'shin, Viktor A., Verkhozina, Olga N., Larina, Lyudmila I., Danilovtseva, Elena N.
• Format: Article
• Language: English
• Subjects: Biomaterials; Chemical synthesis; Composite materials; Nanostructures; Polymers; Precipitation
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/j.matchemphys.2015.09.022

A new polyampholyte based on poly (acrylic acid) which bears pendant polyamine oligomeric chains (average number of the nitrogen atoms is 11.2) is obtained. This polymer is a model of silaffins – proteins playing important role in formation of siliceous structures in diatom algae and sponges. The polymer catalyses condensation of silicic acid. The obtained solutions contain oligosilicates coordinated with the polymer chains. The action of 50,000 g gravity on this solution results in concentrating-induced condensation of the pre-condensed siliceous oligomers. The obtained solid silica contains 4% admixture of the organic polymer which is close to the silica from diatom frustules. These results confirm the hypothesis about formation of biosilica under the action of desiccation agent, e.g. aquaporins. The formation of solid substances during centrifugation of solutions containing soluble oligomers is a new promising approach to inorganic and composite materials which allows to work in aqueous medium and to reuse the organic polymer. [Display omitted] •A polyampholyte with pendant polyamine chains is obtained.•The polymer catalyses condensation of silicic acid giving stable solutions.•Gravity-induced (50,000 g) formation of solid silica was observed in these solutions.•The obtained silica is close to biosilica from diatom frustules.•A new approach to inorganic and composite materials is proposed.