Transient osmotic flows in a microfluidic channel: measurements of solute permeability and reflection coefficients of hydrogel membranes

Abstract

We first highlight theoretically a microfluidic configuration that allows to measure two fundamental parameters describing mass transport through a membrane: the solute permeability coefficient ${\mathcal{L}}_D$, and the associated reflection coefficient $\sigma$. This configuration exploits the high confinement of microfluidic geometries to relate these two coefficients to the dynamics of a transient flow induced by forward osmosis through a membrane embedded in a chip. We then applied this methodology to hydrogel membranes photo-crosslinked in a microchannel with \textit{in situ} measurements of osmotically-induced flows. These experiments enable us to estimate ${\mathcal{L}}_D$ and $\sigma$ and their dependence on the molecular weight of the solute under consideration, ultimately leading to a precise estimate of the molecular weight cut-off of these hydrogel membranes.

References in corpus (2)

• Passive phloem loading and long-distance transport in a synthetic tree-on-a-chip
• Microfluidic osmotic compression of a charge-stabilized colloidal dispersion: Equation of state and collective diffusion coefficient