Elastic property of organized lipid assembly — Effect of water incorporation and chain melting

The effect of electric field on the capacitance of lipid–water dispersion properly aligned on polyvinyl alcohol coated glass electrodes, shows a transition pattern where a rapid change in orientation of the organized lipid assembly takes place for an electric field above a threshold value (Vth), similar to that of Freedericksz’s transition as observed in the case of thermotropic liquid crystals. The splay elastic constant, k11 and the bend elastic constant, k33 have been calculated from the measured values of capacitance of the cell below and above Vth. These values change by several orders of magnitude depending upon the presence of water as well as temperature of chain melting of the lipid moiety.