The mechanical performance of biominerals found in the bones or shells of molluscs offer a vast foundation for the development of bioinspired and biomimetic materials used in e.g. hard coatings with flame retardancy or light-controlled actuators. The inorganic components of such biominerals are often present as crystallographically aligned nanocrystals formed by complex biomineralization processes that are only partly understood. Scientists have tried to draw inspiration from these biominerals to fabricate novel materials with multiple functions that combine e.g. mechanical protection with optical or electronic activity. Such systems can find applications in for instance smart labels for textiles.

Chemists at the Department of Materials and Environmental Chemistry at Stockholm University, in collaboration with colleagues at the MAX IV Laboratory in Lund, are now able to follow and understand how nanoparticles come together and form large and ordered structures. To overcome prior technical difficulties, they employed a novel approach where the assembly process is carried out in a levitated drop, instead of a conventional flat surface, and observed with synchrotron light. Understanding the mechanism of formation of such artificial, ordered nanoparticle arrays can pave the way to integrate nanoparticles with optical, electronic or magnetic properties into novel devices that could be exploited as e.g. smart labels for textiles.

“The discovery that the assembly of synthetic nanocrystals proceeds through a two-step process where nanoparticles first agglomerate into an intermediate disordered state that then rapidly transforms into large ordered arrays is similar to what has been recently observed for many synthetic crystal and biominerals” says Germán Salazar-Álvarez, at the Department of Materials and Environmental Chemistry at Stockholm University.

The research results have been published in the scientific journal Nano Letters.

Agthe, M et al (2016). Following in Real Time the Two-Step Assembly of Nanoparticles into Mesocrystals in Levitating Drops, Nano Letters. DOI: 10.1021/acs.nanolett.6b02586

Contact:

Associate Professor Germán Salazar-Alvarez

Department of Materials and Environmental Chemistry

(german@mmk.su.se)