Glycerol prevents dehydration in lipid cubic phasesElectronic supplementary information (ESI) available: Ellipsometry data, additional GISAXS data and calculation of humidity phase boundaries. See DOI: 10.1039/c5cc03771a

Lipid cubic phase samples dry out and undergo phase transitions when exposed to air. We demonstrate experimentally and theoretically that adding glycerol controllably lowers the humidity at which cubic phases form. These results broaden the potential applications of cubic phases and open up the potential of a new humidity-responsive nanomaterial. The addition of glycerol to lipid cubic phase films is shown to prevent dehydration, allowing exposure to open, ambient environments.