Coming up next
2026-04-23 - 13:30 @ New Gorlaeus, DM 1.09
SLAM Seminar: Robert Style
Title
Using phase separation to make porous hydrogels
Abstract
It is surprisingly difficult for water and solutes to move around inside of most hydrogels. For example, dry, cm-thick hydrogel samples can take days to fully swell in water, while bulky drug molecules often can’t diffuse in or out of many synthetic hydrogels. This is largely due to the small mesh size (typically O(10-100 nm)) of many hydrogels. However, there are many situations where it would be extremely useful to controllably increase the mobility of water or solutes in hydrogels: for example in rapidly-swelling soft actuators or fast-absorbing materials, hydrogels for drug delivery, tissue culture scaffolds, or in selective membranes. To achieve better transport inside hydrogels, a natural solution is introduce additional connected porosity into the hydrogel micro-structure.
A powerful technique for introducing porosity in gels is polymerization-induced phase separation (PIPS). I will demonstrate PIPS in a model hydrogel system, and show how our results reveal what the key parameters are for creating hydrogels with desired microstructure properties. In particular, I will show how we can make rapidly-swelling ‘super-porous’ hydrogels. As part of the work, I will showcase a novel technique for measuring hard-to-obtain properties of soft, wet materials (e.g. permeability, swelling pressure, and compressibility).