Oxford Colloid Group

 

Colloids in Ice

Ice is important in a wide range of research areas, for example in the behaviour of cells in cryopreservation [1], in the freeze-casting of porous ceramics [2], and in the food industry, where fat is trapped by ice in the making of ice-cream [3].

We have previously studied the phenomenon of ice segregation using colloidal particles as a model system [4]. Currently we are studying colloidal particles confined to a monolayer in the vicinity of ice-water interface, which is moving due to a temperature gradient. We observe how the instability of the interface evolves with the advancing system and track how particles pack in front of the interface by analysing the local crystallinity. We are interested in how the advancing interface velocity, the particle properties (such as surface charge and thermal conductivity), packing fraction, and the temperature gradient lead to different engulfment phenomena. Finally, we relate these observations to models for particle entrapment, where super-cooling, wetting, and lubrication all play a role.

We are also interested in the fundamental physical properties of ice including the three-dimensional profile of the ice–water interface, the thermal regelation of particles in ice and the mechanisms of ice segregation. Furthermore, we are interested in related applications including thermo-gels [5] and ice-binding proteins.

 

Key people
References
  • [1] Körber, C. Q. Rev. Biophys (1988), 21, 229-298
  • [2] Deville, S. Advanced Engineering Materials (2008), 10, 155-169
  • [3] Clarke, C. The Science of Ice Cream The Royal Society of Chemistry (2012)
  • [4] Schollick J M H, et. al.. The Journal of Physical Chemistry B (2016) 120(16): 3941-3949
  • [5] Fisher A L et. al.. RSC Advances (2016), 6(71): 66438-66443
http://dullens.chem.ox.ac.uk/colloids-in-ice.aspx