Module 3 Diffusion & Flow
Diffusion and flow are two mechanisms that depending on e.g. external pressure, particle diffusion constant and biomaterial structure may compete for being the dominating mass transport mechanism. In the biomaterials of interest to SuMo the structures are typically 100–200 nanometers, which is the size range where diffusion and flow weighs equal with respect to uptake or release of solutes or solvent. Having access to experimental techniques for characterizing the relative contributions from these two mechanisms is essential for the development of new biomaterials with tailored mass transport properties.
In this module the overall research question is related to how the diffusion and/or flow rates depend on the structure of the material, i.e. mass transport – microstructure relationships. For this purpose we use several different experimental techniques for diffusion and flow characterization at different length- and time scales. Since the structure of a biomaterial may vary greatly depending on its origin so can diffusion and flow. In very crowded structures the mass transport may be very slow making diffusion the dominating mechanisms. In materials with larger structures, such as a cellulose fiber material, the flow mechanism may dominate. This module serves as experimental input to module 2: where the results will be used for validation of mass transport modelling.
Last modified: October 27, 2010