Busselez R, Lefort R, Guendouz M, Frick B, Merdrignac-Conanec O, Morineau D
Institute of Physics of Rennes, CNRS-University of Rennes 1, UMR 6251, F-35042 Rennes, France.
J Chem Phys. 2009 Jun 7;130(21):214502. doi: 10.1063/1.3147222.
Glycerol and trehalose-glycerol binary solutions are glass-forming liquids with remarkable bioprotectant properties. Incoherent quasielastic neutron scattering is used to reveal the different effects of nanoconfinement and addition of trehalose on the molecular dynamics in the normal liquid and supercooled liquid phases, on a nanosecond time scale. Confinement has been realized in straight channels of diameter D=8 nm formed by porous silicon. It leads to a faster and more inhomogeneous relaxation dynamics deep in the liquid phase. This confinement effect remains at lower temperature where it affects the glassy dynamics. The glass transitions of the confined systems are shifted to low temperature with respect to the bulk ones. Adding trehalose tends to slow down the overall glassy dynamics and increases the nonexponential character of the structural relaxation. Unprecedented results are obtained for the binary bioprotectant solution, which exhibits an extremely non-Debye relaxation dynamics as a result of the combination of the effects of confinement and mixing of two constituents.
甘油和海藻糖 - 甘油二元溶液是具有显著生物保护特性的玻璃形成液体。非相干准弹性中子散射用于揭示在纳秒时间尺度上，纳米限域和添加海藻糖对正常液相和过冷液相中分子动力学的不同影响。限域是在由多孔硅形成的直径D = 8 nm的直通道中实现的。这导致液相深处更快且更不均匀的弛豫动力学。这种限域效应在较低温度下仍然存在，在该温度下它会影响玻璃态动力学。与本体系统相比，受限系统的玻璃化转变向低温移动。添加海藻糖倾向于减缓整体玻璃态动力学，并增加结构弛豫的非指数特征。对于二元生物保护剂溶液获得了前所未有的结果，由于两种成分的限域和混合效应的结合，该溶液表现出极其非德拜的弛豫动力学。
