论文部分内容阅读
为研究乙醇-水混合物中分子间的相互作用情形,通过实验测得了不同体积配比的乙醇-水混合物的拉曼光谱。发现位于2800～3050cm-1波数区间的CH伸缩振动频率随乙醇中加入水量的增加整体呈现蓝移趋势,而位于1048cm-1附近的CO伸缩振动频率的变化规律却与此相反。分析了频移产生的原因,并据此得到了不同体积配比的混合物中的分子间相互作用情形和所形成的团簇结构形态。结果表明,水分子加入到纯乙醇中后会与乙醇分子自缔合团簇通过氢键缔合形成水合团簇,随着混合物中水含量的增加,水合团簇的尺寸和数量都相应增加,此过程在水含量为40%时达到饱和;水含量的继续增加会破坏水合团簇结构,使乙醇链解体,水分子包围在乙醇分子周围形成了疏水水合团簇。
To study the intermolecular interactions in ethanol-water mixtures, the Raman spectra of different volume ratios of ethanol-water mixtures were measured experimentally. It is found that the frequency of CH stretching vibration located in the wave number range of 2800-3050 cm-1 shows a blue-shift trend as the amount of water added in ethanol increases. However, the frequency of CO stretching vibration near 1048 cm-1 changes in the opposite direction. The reason of the frequency shift is analyzed, and the intermolecular interaction and the cluster structure morphology of the mixtures with different volume ratios are obtained. The results showed that the water molecules added into the pure ethanol would associate with the self-associating clusters of ethanol molecules to form hydrated clusters through hydrogen bonding. As the water content in the mixture increased, the size and number of hydrated clusters increased accordingly, This process reaches saturation at a water content of 40%; continued increase in water content destroys the hydrated cluster structure, disintegrates the ethanol chain, and water molecules surround the ethanol molecules to form hydrophobic hydrated clusters.