We have studied the impact of particle shape anisotropy, multivalent interactions and flexibility on systems of micron-sized colloidal particles. In short, we have characterized the diffusive... Show moreWe have studied the impact of particle shape anisotropy, multivalent interactions and flexibility on systems of micron-sized colloidal particles. In short, we have characterized the diffusive properties of anisotropic dumbbell particles near surfaces. Furthermore, by using experiments and simulations, we have uncovered marked flexibility-induces effects in the Brownian motion of reconfigurable colloidal structures. Our work demonstrates the rich dynamics and possibilities for applications of shape-changing colloidal systems. We hope our findings further the study of the diffusivity of flexible objects found in complex mixtures relevant in, for example, the cosmetic, pharmaceutical and food industries, as well as in biological and drug-delivery systems. For example, our results may have implications for understanding both the diffusive behavior and the most likely conformations of macromolecular systems such as polymers, single-stranded DNA and other chain-like molecules. Show less
This PhD-thesis presents a study on micron-sized particles, so-called colloids. By controlling the chemical and physical properties of these particles, such as the interparticle interaction... Show moreThis PhD-thesis presents a study on micron-sized particles, so-called colloids. By controlling the chemical and physical properties of these particles, such as the interparticle interaction and the particles’ shape, colloids can act as building blocks that self-assembly into larger structures. This could lead to the development of materials with novel properties such as ‘smart’ materials with the ability to adapt their structure to the environment. In this thesis spherical colloids are used as a starting point to make complex colloidal building blocks and larger microstructures. Anisotropic particles were formed by introducing surface roughness, dents, protrusions and chemical functionalization on the particle surface. Complex structures were obtained by assembling and reconfiguring clusters of spheres. Here, a balance of several phenomena including, the interfacial and potential energy, entropy and geometric constraints, determined the final geometry of the assembled structure. The work also shows how anisotropic elongated particles distorted the hexagonal order in crystals of spheres, either locally or over long distances. These distortions are known to influence the optical, mechanical and electronic properties of colloidal crystals. The complex particles and assemblies made in this study are therefore an important step towards the development of materials with novel and adaptable properties. Show less
