PhD defence: Measuring interactions between colloidal (nano)particles

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Colloids are small particles of between 1 nanometer and 10 micrometer in size, which are typically suspended in a liquid medium. While they are too small to see with the naked eye, particles in this size range are all around us and play a key role both in biological processes, such as proteins and viruses, as well as in artificial applications, such as the pigments in paint and the lipid nano-capsules in modern vaccines.

For most applications, it is important that the particles are either stably suspended in a liquid, or that they can be assembled into functional materials with the right structure for the job. This concept of spontaneous assembly to form novel materials out of simple building blocks is something that nature is particularly good at, and there is considerable interest to apply such an approach to artificial nanoparticles. 

The interaction forces between the particles are crucially important to understand and control the stability of the particles and the structures that they may form. However, these interaction forces are complex to predict, especially when it comes to colloidal nanoparticles. In this research we therefore studied and developed techniques to measure these interaction forces experimentally. We did so, by observing the particles in their surrounding fluid using different light and electron microscopy techniques. We then used statistical analysis of their positions and movement to determine the interactions.

While the research put challenging demands on the microscopy, we were able to show for a few different types and sizes of particles that this can be achieved. Additionally, we discussed how such measurements may best be performed in future research.

Start date and time
End date and time
Location
Academiegebouw, Domplein 29 & online (livestream link)
PhD candidate
M. Bransen
Dissertation
Measuring interactions between colloidal (nano)particles
PhD supervisor(s)
prof. dr. A. van Blaaderen