Water activity in lamellar stacks of lipid bilayers: "Hydration forces" revisited
Abstract
Water activity and its relationship with interactions stabilising lamellar stacks of mixed lipid bilayers in their fluid state are investigated by means of osmotic pressure measurements coupled with small-angle x-ray scattering. The (electrically-neutral) bilayers are composed of a mixture in various proportions of lecithin, a zwitterionic phospholipid, and Simulsol, a non-ionic cosurfactant with an ethoxylated polar head. For highly dehydrated samples the osmotic pressure profile always exhibits the "classical" exponential decay as hydration increases but, depending on Simulsol to lecithin ratio, it becomes either of the "bound" or "unbound" types for more water-swollen systems. A simple thermodynamic model is used for interpreting the results without resorting to the celebrated but elusive "hydration forces"
Keywords
Cite
@article{arxiv.1509.06514,
title = {Water activity in lamellar stacks of lipid bilayers: "Hydration forces" revisited},
author = {R. Leite Rubim and B. B. Gerbelli and K. Bougis and C. L. Pinto de Oliveira and L. Navailles and F. Nallet and E. Andreoli de Oliveira},
journal= {arXiv preprint arXiv:1509.06514},
year = {2016}
}
Comments
24 pages, 12 figures. Accepted for publication in The European Physical Journal E