Crystallization of water in multilamellar vesicles.

The two-step crystallization of water in multilamellar vesicles (MLVs) of phosphatidylcholines has been investigated. The main crystallization occurs near -15 degrees C and involves bulk water. Contrary to unilamellar vesicles, a sub-zero phase transition is observed for MLVs at -40 degrees C that corresponds to the crystallization of interstitial water, as proved by Fourier transform infrared absorption and differential scanning calorimetry (DSC) experiments.