微波电场对甘油水溶液体系中氢键的影响

Effect of microwave field on hydrogen bonds in glycerol aqueous solution system

通过分子动力学模拟考察微波电场对不同水含量甘油溶液中氢键的影响。研究发现:甘油含量高时,甘油分子在溶液中以较大的团簇结构存在,水分子以较小的团簇结构或游离状态存在,电场作用下,大的甘油分子团簇变成较小的团簇并且变得更加有序;随着电场强度继续增加,甘油分子整体结构变化不大,但是团簇结构边缘甘油分子氢键断裂,变成游离状态。对于水分子而言,其较小的团簇结构在电场作用下被打开,团簇结构消失,水分子在电场方向上整齐排布,且电场强度继续增大,其结构变化不大,同样个别水分子氢键断裂变成游离状态。因此,甘油浓度高时,水分子间氢键数减少,甘油分子氢键数先增大后略微减少;甘油浓度低时,水分子氢键数先增大后略有减少,甘油分子间氢键减少。

Molecular dynamics simulation was employed to investigate the effect of the microwave on the hydrogen bond in the glycerol aqueous solution with different concentration. It was observed that at higher glycerol concentration, glycerol molecules existed in large clusters, whilst water in small clusters or at free state. The clusters of glycerol molecules changed from large to small and became more ordered under the electric field. As the electric field intensity further increased, the overall structure of glycerol molecule did not change obviously, the hydrogen bonds at the edge of glycerol clusters were found broken. For water molecules, smaller clusters under the effect of electric field were broken and disappeared, so water molecules were arranged neatly in the direction of electric field. As the electric field intensity continues to increase, the structure of water remained unchanged, and the hydrogen bonds of water changed to a free state. Therefore at higher glycerol concentration, the hydrogen bonds of water decreased, and those of glycerol first increased and then decreased slightly;at lower glycerol concentration, hydrogen bonds of water increased first and then decreased slightly, while those of glycerol decreased.