J. Phys. France
Volume 51, Numéro 10, mai 1990
Page(s) 1027 - 1048
J. Phys. France 51, 1027-1048 (1990)
DOI: 10.1051/jphys:0199000510100102700

Adhesion in egg lecithin multilayer systems produced by cooling

W. Harbich et W. Helfrich

Freie Universität Berlin, Fachbereich Physik, Arnimallee 14, D-1000 Berlin 33, F.R.G.

Slightly hydrated egg lecithin was aligned mostly parallel to the glass plates of the sample cells by squeezing it to a thickness of 20 μm. The rest of the cell was filled with water and the lipid was left to swell at elevated temperatures to bilayer mean spacings between 3 and 17 nm. Cooling by a few °C gave rise to induced adhesion in the semicylindrical border (and myelin cylinders) where the mean spacing was larger than in the bulk. From the contact roundings of membranes adhering to stacks of other membranes we obtained the lateral tension (dyn cm-1) inducing the adhesion as a function of the equilibrium mean spacing. An extensive analysis of the data in terms of van der Waals attraction and undulatory repulsion leads to serious contradictions. They suggest the intervention of a new, submicroscopic roughness of unstressed lecithin membranes absorbing plenty of membrane area.

8715 - Biomolecules: structure and physical properties.
8716D - Membranes, bilayers, and vesicles.

Key words
adhesion -- lipid bilayers -- van der Waals forces