Dielectric dispersion in the ripple phase of DPL mixtures in water

Abstract

We have investigated, by means of radiowave dielectric spectroscopy measurements, the ripple phase of two different phospholipid — water mixtures (DPPC and DMPC), each of them containing different amounts of DPPE or DMPE, respectively, up to 7% wt/wt of total lipid. — Addition of DPPE or DMPE to the phospholipid aqueous systems should reduce the effective head group area and, hence, the orientational head group dipole correlation. The results, showing a marked damping of the dielectric increment at the pretransition in relation to the DPPE or DMPE concentration, provide further evidence that the anomalous polarization observed in these systems at the pretransition temperature must be attributed to the bilayer ripple modulation.