Dr Pietro Cicuta. Equilibrium and non-equilibrium dynamics in membranes.
Date: 22 January 2014 Time: 15:00 - 16:00
Dr Pietro Cicuta
Work in the last decade has explored the thermodynamics of lipid mixtures, showing for compositions that mimic biological membranes the presence of a critical point for phase separation. This is interesting for two reasons: (a) very nice physics, typical of two dimensional systems; (b) exploring possible biological relevance of this fact. The dynamics of objects embedded in membranes is richer than in the bulk, due to the coupled flows in the membrane and in the adjacent liquid phases. These are aspects on which we had worked in equilibrium conditions, and they will be reviewed. More recently, we have begun experiments (unpublished) in which we perturb these same system out of equilibrium (by fast temperature changes), and we observe the morphology of domains of coexisting composition, as they relax to the new equilibrium state. For example, quenching the system so that the domains suddenly become miscible leads to a transient length scale that we attribute to the viscous fingering instability, and to a rich sequence of physical phenomena that can be visualised very directly.
|Location:||PP1 Lecture Theatre|