应用低场核磁共振（1H LF-NMR）技术对不同浓度水-乙醇二元体系的弛豫特性进行了研究，并结合分子模拟计算获得的体系的氢键变化进行了分析。结果表明，不同浓度下水-乙醇体系的氢键缔合状态可引起低场核磁弛豫特性的变化。对0%≤XW≤10%的水-乙醇体系而言，水与乙醇可通过氢键形成H2O(EtOH)n团簇，表现为T21先增加，后减小并保持相对稳定，而单组分弛豫时间(T2w)逐渐减小。对10%≤XW≤100%的水-乙醇体系而言，单组分弛豫时间T2w呈先缓慢减小再逐渐增加的趋势；当10%≤XW＜30%时，乙醇分子间缔合为主，形成(H2O)m(EtOH)n团簇，T21先相对稳定再减小。当30%≤XW≤60%时，单体水分子与乙醇自缔合团簇的结合逐渐达到饱和，T21再次呈相对稳定的现象。当60%＜XW≤100%时，体系内以水分子间的氢键缔合为主，且(H2O)m(EtOH)n团簇解离，T21呈增大趋势。

The 1H LF-NMR and molecular simulation methods were adopted to investigate the water-ethanol solution with different water concentrations. The results indicated that the interaction between hydrogen bond association and water content in water-ethanol solution can cause the relaxation characteristics change. In low concentration of water-ethanol (0%≤XW≤ 10%) system, when adding water to ethanol, part of the water and ethanol tend to form H2O(EtOH)n clusters through hydrogen bonding, multi-component relaxation time T21 at first increases, then decreases and remains relatively constant, while T2W decreased. For the high concentration of water-ethanol (10%≤XW≤100%) system, after minor reduction, T2W increased when the water concentration increased. When 10%≤XW＜30%, due to ethanol self-association and corresponding (H2O)m(EtOH)n clusters, T21 decreases after showing a relatively constant stage. When 30%≤XW≤60%, the saturation of single water molecule combined with ethanol self-association clusters could be reached, T21 turned to be relatively constant. When 60%≤XW≤100%, water self-association would be found and (H2O)m(EtOH)n clusters dissociated, then T21 appeared to increase.

国家自然科学基金项目(NSFC31201365)；上海市科委重点攻关项目(11142200403)；上海市教委科研创新项目(11YZ109)；上海市东方学者跟踪计划；上海市联盟计划项目资助(LM2013251)；上海市产学研合作年度计划（沪CXY-2013-51）