Applications of random surfaces to fluid mixtures.
Gerhard Gompper
Abstract
One of the current challenges in Physics and Biology is to gain a
better understanding of the mechanical and thermal properties of fluid
membranes.
These surfaces are monolayers of amphiphilic molecules at an oil/water
interface, or bilayers in water.
In contrast to (i) interfaces between bulk liquids in two-component fluid
mixtures
or (ii) soap bubbles, the shape
and fluctuations of membranes are controlled by their bending rigidity
instead of the surface tension. The bending rigidity of membranes is
typically small, so that thermal
fluctuations can dramatically influence the structure and phase behavior of
membranes and membrane networks. Monte Carlo simulations of random surface
models have therefore
been an important tool to study these systems /1/. The unusual thermal
properties of membranes will be discussed for two
examples:
- the sponge-to-lamellar transition, which is driven by
fluctuations of the membrane topology /2,3/,
- the fluid-to-crystalline transition of vesicles /4/, which is
governed by a proliferation of topological defects.
/1/ G. Gompper and D.M. Kroll, J. Phys. Condens. Matter 9, 8795 (1997).
/2/ G. Gompper and D.M. Kroll, Phys. Rev. Lett. 81, 2284 (1998).
/3/ H. Endo, J. Allgaier, G. Gompper, B. Jakobs, M. Monkenbusch, D. Richter,
T. Sottmann and R. Strey, Phys. Rev. Lett. {\bf 85}, 102 (2000).
/4/ G. Gompper and D.M. Kroll, Phys. Rev. Lett. 78, 2859 (1997); J. Phys. I
France 7, 1369 (1997).
Elenco dei partecipanti al convegno di Bari.