Probing Water State during Lipidic Mesophases Phase Transitions

We investigate the static and dynamic states of water network during phase transitions from double gyroid ( ) to diamond bicontinuous cubic phases latter reverse hexagonal (HII) in monolinolein based lipidic mesophases by combining FTIR broadband dielectric spectroscopy (BDS). In both cubic(s) HII phase, two dynamically different fractions are detected attributed bound interstitial free water. The dynamics all slower than bulk due hydrogen-bonds between molecules lipid's polar headgroups nanoconfinement. Both BDS results suggest that a larger fraction is hydrogen-bonded headgroup lipids at higher temperature lower via H-bonds, which common expectation number H-bonds should decrease with increase temperature. These findings rationalized considering topological ratio interface/volume mesophases.