MSE Research Project Database

Shape matters: surface forces between anisotropic nanoparticles


Project Leader: Ray Dagastine
Sponsors: Australian Research Council
Primary Contact: Ray Dagastine (rrd@unimelb.edu.au)
Keywords: drops and bubbles; nanostructured materials; surface forces
Disciplines: Chemical & Biomolecular Engineering
Domains: Convergence of engineering and IT with the life sciences
Research Centre: Particulate Fluids Processing Centre (PFPC)

This project involves studying the diffusion and assembly of nanoparticles relevant to a number of industrial processes. Engineering materials with deliberately tuned properties by controlling their structure at the nanoscale has the potential to unlock an enormous number of applications in medical, computing, renewable energy, food and chemical processing industries. For example, structurally aggregated zinc oxide rods or carbon nanotubes may be used in the “bottom-up” fabrication of solar cells, nanoelectronic and photonic devices. A major obstacle to the widespread adoption of “bottom-up” nanofabrication in industrial processes is a lack of understanding about how complex colloidal particles, like carbon nanotubes, move and fit together to form a film.

This project’s overall goal is to measure the particle–particle and particle–surface interactions that control the self-assembly of these particles into advanced materials.

Traditional optical microscopes are unable to resolve the nanoscale interactions between anisotropic nanoparticles and the substrate for film formation, often limited to larger particles of spherical particle geometries.  Thus making direct observations of the kinds of interactions that seem to is critical to improving particle based coatings, but there is a lack of methods to quantify these interactions.Using a laser-microscopy technique developed very recently by the Dagastine group, we can bypass the optical diffraction limit to perform measurements of particle position and orientation on millisecond timescales. This project will be among the very first users of this new kind of microscope, and it is expected that this project will contribute to its ongoing development as a research tool.

These anisotropic particles will be used to further develop the theory and instrumentation required to apply this new technique to a wide range of systems (eg, both commercial particles, carbon nanotubes, ZnO crystals, viruses, as well as fabricated particle systems). The approach in this work will further derive/validate a general physical theory for nanoparticle interactions that takes into account the effects of shape and composition and apply this in in film formation for specific systems.

Further information: https://chemical.eng.unimelb.edu.au/dagastine/