Controlling growth and form of carbonate crystals

3 April 2018

An international team of researchers including Jaap Kaandorp of the University of Amsterdam show new results about bio-inspired controlled crystal growth using experiments and computational models. The research is published in the Proceedings of the National Academy of Sciences (PNAS).

The researchers from AMOLF (Wim Noorduin), Virginia Tech (Ling Li), TU Eindhoven (Remco Fijneman), Harvard University (Joanna Aizenberg) and Jaap Kaandorp (Informatics Institute-UvA) have successfully manipulated both the local super-saturation and lattice mismatch to effectively promote crystal nucleation and steer the growth of mineralizing shapes. For this they took advantage of the tendency of calcium carbonate—the most abundant biomineral—to crystallize in different crystal packings e.g. polymorphs.

By controlling the inflow of CO2 the researchers could successfully nucleate other carbonate salts on specific polymorphs and also grow towards them. These results highlight that even the simple interplay between different physical and chemical phenomena already can lead to a highly complex shapes.

 

Growth and form of BaCO3 crystals (in pink and white) nucleated on CaCO3 crystals (blue) (picture by Ling Li, Jinjin Zhong,(Virginia Tech.) and Wim Noorduin (AMOLF))

In living systems CaCO3, Ca phosphates and silicate crystals are the fundamental mineralized structures. All around us, organisms seemingly effortlessly steer the precipitation of these minerals into a wide diversity of intricately shaped mineral architectures with a precise control over the shape and positioning.

Understanding and ultimately controlling these processes forms a formidable fundamental challenge with direct practical ramifications in fields ranging from medical implants for the promotion of bone growth, to completely artificial functional materials such as optical micro-architectures.

Published by  Faculty of Science