Filtration of soft particles: from microgels to proteins
G. Nägele, R. Roa and J. Riest (all at ICS-3, FZ Jülich)
Microgels have a variety of applications including drug delivery and photonic crystals. We model theoretically sustainable membrane filtration processes for the concen- tration, purification, and separation of microgels. A suspension of microgel particles is pumped through a cylin- drical fiber membrane, and the permeate flux and the formation of a
concentration polarization layer at the membrane surface are analyzed. On taking advantage of our knowledge basis on the calculation of transport coefficients of concentrated microgel systems [1,2] and proteins [3], we study presently a macroscopic cross-flow filtration model for microgels and globular proteins based on the advection-diffusion equation for the solute particles, on Darcy’s law for the membrane, and the Navier-Stokes equation for the solvent flow [4]. In future work, we will analyze the microscopic structure of the polarization and cake layers by generalizing the dynamic density functional theory (DDFT) approach to account for non-potential solvent flow.
This work is part of the B6 project of the new SFB 985. It is done in close collaboration with a process engineering group (membrane modification and microgel filtration experiments) and a physical chemistry group (flow and filtration cake layer visualization with fast NMR imaging) at the RWTH Aachen.
References:
[1] P. Holmqvist, P.S. Mohanty, G. Nägele, P. Schurtenberger and M. Heinen,
[2] J. Riest, T. Eckart, W. Richtering and G. Nägele, paper to be submitted (2014).
[3] M. Heinen, G. Nägele, and biophysics group of F. Schreiber (U. of Tübingen), Soft Matter 8, 1401 (2012).
[4] R. Roa and G. Nägele, work in progress (2014).
