DMSO溶液玻璃化过程氢键生命期特性

引言 许多液体被冷却到某个特征温度时,容易结晶,这个温度是熔融温度.这个过程中,首先形成晶核,然后晶体生长,无序的分子排列于是变得高度有序.但是只要超过一定速度降温到另外一个特征温度,液体就能避免结晶,这个特征温度被称为玻璃化温度.随着液体的温度被降到玻璃化温度以下,液体分子还是保留着无序的状态.

Life properties of hydrogen bonds of DMSO aqueous solution during vitrification

For the purpose of understanding the life characteristics of hydrogen bonds of DMSO aqueous solution during vitrification, molecular simulations were carried to calculate hydrogen bonds for 70% DMSO aqueous solution cooled with two cooling rates, 1×107 K·s-1 and 1×1012 K·s-1.The life distribution of hydrogen bond was calculated.As temperature decreases, following results are obtained.(Ⅰ)The life distributions of the system, DMSO H2O and H2O H2O hydrogen bonds all oscillate in higher magnitude.(Ⅱ)The life distribution of DMSO H2O hydrogen bonds is greater than that of H2O H2O when time >3 ps.(Ⅲ)The life distributes in a manner similar to power or exponential functions in which independent variable is multiplied by a negative factor.(Ⅳ)The average life of DMSO H2O hydrogen bonds is longer than that of H2O H2O.(Ⅴ)The vibration amplitudes of life distributions of the system, DMSO H2O and H2O H2O hydrogen bonds and their changes in the system cooled with higher cooling rate are lower than those with lower cooling rate