Hamburg 2001 – wissenschaftliches Programm
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DY: Dynamik und Statistische Physik
DY 43: Kritische Ph
änomene und Phasenumwandlungen
DY 43.9: Vortrag
Donnerstag, 29. März 2001, 12:30–12:45, S 7
Fluctuation Pressure of a Stack of Membranes — •Michael Bachmann, Hagen Kleinert, and Axel Pelster — Institut für Theoretische Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin
Membranes formed from lipid bilayers are important
biophysical systems occuring as boundaries of organells and vesicles.
In equilibrium with a reservoir of molecules,
tension vanishes and
the shape is governed by extrinsic curvature energy EC.
If a stack of membranes is placed between two parallel walls, violent
thermal out-of-plane
fluctuations of the membranes exert a pressure p upon the walls.
Helfrich [1] proposed an ideal-gas-like pressure law with a universal
pressure constant which is not calculable exactly.
We evaluate this pressure constant
by strong-coupling theory [2] for different numbers of membranes in the
stack. The
results are in very good agreement with values from Monte-Carlo simulations
[3].
Our work extends the discussion in
Ref. [4], where we applied strong-coupling theory to calculate the pressure
constant
for a single membrane between the walls which is in perfect agreement with
Monte-Carlo
simulations [3].
[1] W. Helfrich, Z. Naturforsch. A 33, 305 (1978).
[2] M. Bachmann, H. Kleinert, and A. Pelster, eprint:
cond-mat/0011281.
[3] W. Janke, H. Kleinert, and M. Meinhart, Phys. Lett. B 217, 525
(1989);
G. Gompper and D.M. Kroll, Europhys. Lett. 9, 59 (1989).
[4] M. Bachmann, H. Kleinert, and A. Pelster, Phys. Lett. A 261, 127
(1999).