Student Thesis Seminar
"Phase Behavior of Polyelectrolyte-Surfactant Complexes at Planar
Surfaces"
Adi Shafir
Dept. of Condensed Matter Physics, Tel Aviv University
Insoluble surfactant (surface active material) monolayers at the water/air
interface are called Langmuir Monolayers and mimic many properties of
biological membranes. As function of lateral pressure and temperature, the
monolayer undergoes several phase transitions. We use mean-field theory to
investigate the phase behavior of such monolayers, in the case where the
surfactants are electrically charged, and are in contact with a
semi-dilute solution of oppositely charged polyelectrolytes. This
situation resembles the interaction of a biological cell membrane with
various charged macromolecules. We calculate the effect of the chains on
the phase diagram on the of the monolayers as well as the role the
surfactant monolayer has on the adsorption of the polyelectrolytes as
function of the long-range electrostatic interactions and short-range
interactions between the polyelectrolytes and the surface.
Thesis Adviser: Prof. David Andelman, x7239
|