The synthesis of nanoparticles and nanostructures with well-defined sizes, morphologies and hierarchical structures represents one of the great challenges in nanoscience and nanotechnology today. While it is well known that additives such as block copolymers can mediate the formation of an enormous range of crystal morphologies, understanding of these events is little better than empirical, and the synthesis of particles with different morphologies is typically carried out on a trial-and-error basis. Progress can only be made by understanding how nanoparticles nucleate, grow, and assemble. We will address this here using a combination of theory and experiment with the ambitious goal of developing strategic syntheses of nanomaterials.
Achievements so far, June 2013
- For the first time, in situ electron microscopy studies of the precipitation of carbonates with and without additives have been performed using fluid cell TEM and ASEM.
- Provided an in-depth analysis of the structure of the sea urchin spine, revealing a complex, hierarchical structure. These biominerals can be classified as mesocrystals.
- Shown that the structure of synthetic calcite “mesocrystals” do not form via an assembly of crystalline units; no evidence for nanoparticle subunits. These are not mesocrystals.
- For the first time, demonstrated crystals of phases other than calcium phosphate within collagen. Generating a new understanding of the mechanisms by which collagen system controls crystallisation; and generally of the effect of confinement on crystallisation.
- Demonstrated that poly(allyl amine hydrochloride) can induce changes in CaCO3 morphologies. Challenging the accepted idea that positively charged additives are ineffective in directing mineral formation.