BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:The dynamics of super-absorbent hydrogels - Grae Worster\, DAMTP
DTSTART:20221007T150000Z
DTEND:20221007T160000Z
UID:TALK182939@talks.cam.ac.uk
CONTACT:Prof. Jerome Neufeld
DESCRIPTION:Super-absorbent polymers placed in water can form hydrogels wi
 th polymer fractions of less than 1% by volume\, with the water molecules 
 being adsorbed by the hydrophilic polymer to form an elastic material. The
 y are used in disposable diapers\, for soil remediation\, for controlled d
 rug delivery and as actuators in microfluidic devices. Hydrogels are also 
 a component part of the xylem\, through which water is transported upwards
  in trees. The water is not fixed in place but can flow through the porous
  polymer scaffold to drive swelling\, drying and transpiration. We have de
 veloped a new mathematical approach to model super-absorbent hydrogels\, w
 hich allows for strongly nonlinear swelling while remaining linear in devi
 atoric strains\, in effect treating hydrogels as instantaneously incompres
 sible\, linear elastic materials with inhomogeneous elastic properties rel
 ated to the differential swelling states. I will describe this model and i
 llustrate its features by solving simple examples of swelling spheres and 
 transpiration through cylinders\, and by analysing different instabilities
  that can arise during swelling and drying. I will also introduce a hypoth
 esis for a potential role of hydrogels in pumping water up very tall trees
 .
LOCATION:MR2\, Centre for Mathematical Sciences\, Wilberforce Road\, Cambr
 idge
END:VEVENT
END:VCALENDAR