title: Controlling microtube permeability via grafted polymers and solvent quality.
abstract: We examine pressure-driven flow through a microtube with grafted polymers using a "doubly self-consistent field" steady-state theory. Our focus is on the structure of the polymer layer, the tube permeability, and the effects of solvent quality, for different regimes of open and closed tubes. We find that, within experimentally attainable pressure gradients, the flow has very little effect on the grafted layer. However, the polymers, and in particular variations in the solvent quality and cylinder radii, can have large effects on the flow. We find that the permeability can either increase or decrease with either the radius or solvent quality, and we identify the regimes for different behaviors in terms of general parameters that can be used to generalize to other systems. This allows us to identify regimes where the systems are most sensitive to these "tuning" parameters, and we find that they correspond to the boundaries between open and closed tubes identified earlier.
authors.affiliation: Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada.
authors.forename: Tongchuan
authors.initials: T
authors.lastname: Suo
authors.affiliation: Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada.
authors.forename: Mark D
authors.initials: MD
authors.lastname: Whitmore