My PhD thesis

The pages that follow are web-versions of the chapters of my PhD thesis. You can also download the pdf-version if you prefer.

Abstract

The simple bonding geometry of carbon atoms is at the basis of materials ranging from wood to diamonds. In my thesis, we take the first steps on a similar path: we experimentally explore the assembly of so-called “patchy particles”, colloidal particles with directional bonding sites, and reveal how these controllable building blocks can be assembled into a range of different structures.

Particles are assembled into “colloidal molecules”, small colloidal clusters with similar bonding geometry to alkanes, and show these structures undergo similar chemical processes as regular molecules. We also build bigger superstructures: a honeycomb lattice is assembled from trivalent particles confined to a two-dimensional plane. We study the defects, dynamics, and ageing of this “colloidal graphene”. Under certain conditions, a similar system can yield other architectures: an amorphous network and a triangular lattice. We elucidate the phase diagram of the system, highlighting the rich assembly behaviour of these simple particles. Finally, we use a mix of di- and trivalent particles to assemble into a network - yielding a so-called “equilibrium gel”. This structure looks like a gel, but is in equilibrium; a very counterintuitive combination.

This exploratory work should be seen as the basis for the design of more advanced future smart materials, with precisely tunable mechanical, electronic and optical properties. Future ‘colloidal architects’ may have abilities approaching that of nature: with excellent control over the building blocks of a material comes excellent control over the macroscopic material properties.