Interactions between liquids and fibers or fibrous materials are found in numerous natural and engineered systems. The model system of a liquid volume on two rigid fibers has been studied to understand these interactions on a fundamental level. While the equilibrium shapes of liquid volumes on the two-fiber model system and their stability have been examined, few studies discuss the dynamics of transitions between the equilibrium shapes. In this master thesis, I investigate the dynamics of transitions between these equilibrium shapes, drops and columns, by conducting systematic experiments on spontaneous and forced shape transitions. Spontaneous shape transitions are found to be highly sensitive to external influence and to occur at different critical inter-fiber distances, depending on the liquid volume. Forced shape transitions are found to occur in one step or two steps, depending on the final inter-fiber distance and the liquid volume. A theoretical model for the forced spreading of a drop into a column shape is proposed and validated by experimental data for various values of inter-fiber distance as well as liquid viscosity and volume. This fundamental analysis contributes to the understanding of wetting processes in fibrous materials.     «

Interactions between liquids and fibers or fibrous materials are found in numerous natural and engineered systems. The model system of a liquid volume on two rigid fibers has been studied to understand these interactions on a fundamental level. While the equilibrium shapes of liquid volumes on the two-fiber model system and their stability have been examined, few studies discuss the dynamics of transitions between the equilibrium shapes. In this master thesis, I investigate the dynamics of trans...     »