Structural relaxations of phospholipids and water in planar membranes
Artikel i vetenskaplig tidskrift, 2009

We have used dielectric spectroscopy and temperature modulated differential scanning calorimetry TMDSC to investigate the structural relaxation processes and phase transitions of water and lipids in multilamellar, planar phospholipids. At low hydration levels we observe the main structural relaxation related to the glass transition of the phospholipids. With increasing water content a more pronounced pretransition, attributed to a gel to ripple phase transition, is observed in the TMDSC data. In the proximity of this pretransition, a distinct change in the temperature dependence or alternatively a bifurcation into two processes is observed in the dielectric data. Around this temperature a crossover in the long-range ionic conductivity across the membranes is also observed, which is one of the key parameters for biological membranes. Thus, the major dynamical changes do not occur at the main, i.e., the gel to liquid structural phase transition, but at a pretransition that occurs roughly 20 K below the main transition.


Christer Svanberg

Chalmers, Teknisk fysik, Kondenserade materiens fysik

Peter Berntsen

Chalmers, Teknisk fysik, Kondenserade materiens fysik

Andreas Johansson

Chalmers University of Technology

Therese A Hedlund

Chalmers, Teknisk fysik

Erika Axén

Chalmers, Teknisk fysik

Jan Swenson

Chalmers, Teknisk fysik, Kondenserade materiens fysik

Journal of Chemical Physics

0021-9606 (ISSN) 1089-7690 (eISSN)

Vol. 130 035101- 035101



Den kondenserade materiens fysik