高压作用下相分离液体玻璃转变的分子动力学研究

采用分子动力学模拟方法,研究了二元混合液体在不同外压作用下的相分离与玻璃转变过程,计算了相分离液体在玻璃转变过程中的结构和动力学特征.研究发现,外压会促进相分离的产生,并提高玻璃转变温度,会使β弛豫出现的温度更高、存在的时间更长,导致系统扩散性降低.同时还发现,相分离液体的玻璃转变过程存在微观不均匀现象.关键词：相分离玻璃转变分子动力学模拟外压影响

Molecular dynamics investigation of the glass transition at high-pressure in the phase separation liquid

Molecular dynamics simulation is performed to study the phase separation and the glass transition of a binary liquid mixture when the external pressure is increased from 0 to 2.75 GPa. The structure and dynamic characteristics in the glass transition process are calculated. We find that external pressure will promote the phase separation, and make the glass transition temperature increase. The external pressure will make the transition temperature become higher, at which the β relaxation emerge, the time of β relaxation becomes longer, and the diffusibility of the system becomes lower. We first found that in the phase separation liquid microscopic heterogeneity exists during the glass transition.