Many membrane technologies including water purification, fuel cells, and drug delivery utilize thin swollen polymer network layers to regulate transport. Thus, understanding the critical time- and length-scale regulating their transport behavior is critical to developing membrane materials with enhanced performance. In this contribution, we present an indentation approach to quantify the poroelastic relaxations of thin or geometrically confined hydrogel layers. By compressing the material at a fixed displacement with a macroscopic spherical probe, the poroelastic relation can be identified, which can be correlated to several material properties including diffusion coefficient, shear modulus, and average pore dimensions of the hydrogel. To understand the role of geometric confinement, we develop quantitative relationships linking poroelastic relaxations to materials properties. Finally, we compare these relationships to experimental results by investigating the effects of hydrogel film thickness and network structure on the changes in poroelastic relaxations.

Quantifying the transport properties of thin polymer gel layers via an indentation-based technique

242nd National Meeting (2011)

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