Issue 33, 2016

Systematic characterization of polycrystalline silica–carbonate helices

Abstract

Biomorphs are complex, life-like structures that emerge from the precipitation of barium carbonate and amorphous silica in alkaline media. Despite their inorganic nature, these microstructures have non-crystallographic morphologies such as helices and cardioid sheets. At the nanoscale, biomorphs arrange thousands of crystalline nanorods as hierarchical assemblies that resemble natural biominerals suggesting novel approaches towards the production of biomimetic materials. We report the synthesis of silica–carbonate biomorphs in single-phase, gradient-free solutions that differ markedly from the typical solution–gas or gel–solution setups. Our experimental approach significantly increases the duration of biomorph growth and hence assembles networks in which individual helices extend to several millimeters. These unusually long biomorphs allow the first quantitative measurements of mesoscopic parameters such as the helix wavelength, period, width, and linear as well as tangential growth velocities. We find that the latter quantities are system-specific and tightly conserved during many hours of growth. Moreover, the average double helix wavelength of (19 ± 3) μm and width of (9.6 ± 0.8) μm vary by less than 12% when the initial carbonate concentration is changed by three orders of magnitude. We also delineate the single helix growth mechanism and report the occurrence of ribbon-like structures and highly regular “superhelices”. Our experiments clearly demonstrate the robustness and consistency of biomorph growth under stable chemical conditions.

Graphical abstract: Systematic characterization of polycrystalline silica–carbonate helices

Supplementary files

Article information

Article type
Paper
Submitted
14 Jun 2016
Accepted
26 Jul 2016
First published
26 Jul 2016

Phys. Chem. Chem. Phys., 2016,18, 23044-23052

Systematic characterization of polycrystalline silica–carbonate helices

E. Nakouzi, P. Knoll, K. B. Hendrix and O. Steinbock, Phys. Chem. Chem. Phys., 2016, 18, 23044 DOI: 10.1039/C6CP04153A

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements