Abstract
Complex electric permittivity spectra of aqueous vesicle solutions, prepared by extrusion of lecithin suspensions, have been measured as a function of temperature in order to study the dielectric relaxation of the dipolar phospholipid headgroups. Solutions of unilamellar liposomes from dimyristoylphosphatidylcholine and from a mixture of dimyristoyl- and dipalmitoylphosphatidylcholine (mole fraction x = 0.5) have been investigated. Based on a theoretical model that considers the internal electric fields of the dielectrically heterogeneous liquids, the vesicle radius, the zwitterion relaxation time, a relaxation time distribution parameter, and a quantity that is directly related to the dipole orientation correlation factor are calculated from the measured spectra. The radii indicate a noticeable swelling when T exceeds the gel/fluid phase transition temperatures Tm of the membranes. There clearly exists an effect of correlation of dipole orientations. Either the dipole orientation correlation factor or th...
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
