利用拉曼光谱与超额拉曼光谱研究室温下不同质量分数的(NH₄)₂SO₄水溶液中氢键网络结构的变化,以及离子缔合情况;研究2800~4000 cm ^-1处的O-H伸缩振动区间以及940~1020 cm ^-1处的S O42-全对称伸缩振动区间的拉曼光谱,对拉曼数据进行分峰处理,并对超额拉曼光谱的正、负峰积分面积进行分析。结果表明:质量分数12.00%是溶液中氢键结构以及离子缔合情况发生较大变化的转折点;当质量分数大于12.00%后,溶液中DDA型和DAA型氢键结构增多,DDAA型、DA型氢键结构与自由OH型氢键结构减少,并且溶液中离子对的存在情况也发生了变化,N H4+与S O42-形成了接触离子对。

The changes of hydrogen bond structures and the ion association of (NH4)2SO4 aqueous solution with different mass fractions at room temperature are investigated by Raman spectroscopy and excess Raman spectroscopy. The stretching vibration interval of O-H at 2800-4000 cm -1 and holosymmetric stretching vibration interval of S O42- at 940-1020 cm -1 are studied. The peak splitting of Raman data are handled, and positive and negative peaks integral areas of excess Raman spectra are analyzed. The results show that the mass fraction of 12.00% is the turning point of the hydrogen bond structures and the ion association in the solution. When the mass fraction is greater than 12.00%, the hydrogen bond structures of DDA type and DAA type increase, and the hydrogen bond structures of DDAA type and DA type as well as free OH decrease. The existence of ion pairs changes in the solution and N H4+ forms contact ion pairs with S O42-.