Theory of the asymmetric ripple phase in achiral lipid membranes
Raman Research Institute - C V Raman Avenue, Bangalore 560 080, India
2 National Centre for Biological Sciences (TIFR), GKVK Campus - Bangalore 560 065, India
Accepted: 1 July 2011
We present a phenomenological theory of phase transitions in achiral lipid membranes in terms of two coupled order parameters —a scalar order parameter describing lipid chain melting, and a vector order parameter describing the tilt of the hydrocarbon chains below the chain-melting transition. Existing theoretical models fail to account for all the observed features of the phase diagram, in particular the detailed microstructure of the asymmetric ripple phase lying between the fluid and the tilted gel phase. In contrast, our two-component theory reproduces all the salient structural features of the ripple phase, providing a unified description of the phase diagram and microstructure.
PACS: 87.16.D- – Membranes, bilayers, and vesicles / 61.30.Dk – Continuum models and theories of liquid crystal structure
© EPLA, 2011