Hydration Water Freezing in Single Supported Lipid Bilayers

Figure 2

Elastic neutron scattering as determined in slow cooling and heating cycles. (a) Detectors D5–D8 cover lipid diffusion. (b) Lipid acyl-tail dynamics were observed in D13. (c) D16 covered hydration water dynamics. Freezing and melting transitions are labeled (1)–(6) and the corresponding temperatures are given. All heating curves are shifted upward in intensity for clarity; the original data show closed loops. Error bars represent one standard deviation. The experimental temperature resolution was 0.2 K. The error in the determination of the transition temperatures is related to the determination of the intersection of the different slopes. For lipid dynamics we estimate the maximum error to be ~2 K. The hydration water data in (c) has slightly larger statistical errors and the maximum error in the determination of the transition temperature was estimated to be ~4 K.