A new structural phase change at −60 °C and atmospheric pressure was observed in the gel phase of aqueous DMPC dispersions. This gel–gel phase transition exhibits first-order characteristics and is equivalent to the phase transition observed at 2.6 kbar and 30 °C. The decrease in temperature has analogous effects on the ordering of the acyl chains in DMPC as has the increase in pressure. The rigid interchain reorientational fluctuations in the gel phase are gradually damped with decreasing temperature and below −60 °C the interchain orientation becomes highly ordered.
Canadian Journal of Chemistry60, no. 16: 2137–2140.