The Effects of Particles on the Dynamics of Sheared Droplets
Polymer blending is a commonly used technique to create new polymer materials that combine the properties of their components. Polymer blends are multiphasic materials and hence, their final material properties not only depend on the type of polymers and concentration, but also on the final blend microstructure. This microstructure is formed during processing wherein a complex flow field is applied. Hence, understanding the relation between the applied flow during processing and the structure development in polymer blends is crucial to tailor and design their material properties. When dealing with blends that contain (nano)particles at the interface or in the bulk, new possibilities to tune their properties become feasible. Solid particles are therefore often added to polymer blends to improve their performance or introduce an additional functionality. The morphology of these blends can be substantially affected by the addition of particles and can be investigated by optical microscopy, e.g. in a counter-rotating device. In the long run, understanding and generating concentrated blends with controlled interfacial characteristics will be the ultimate challenge. Finally, rather than having a structured interface these materials can have a structured matrix or internal phase that imparts an additional degree of freedom for controlling the development of the microstructure. However, the intrinsic effects of particles on the structure development remains essentially unexplored and is still poorly understood. Therefore, the effects of particles on the structure development of blends are investigated in this dissertation by means of a fundamental study of the single droplet dynamics. The dynamics of single particle-filled and particle-covered droplets are studied microscopically with a counterrotating shear cell.