【摘要】 根据标准加入法原理配制一系列含有已知微量水的离子液体四氟硼酸-1-戊基-3-甲基咪唑([C5mim][BF4])样品,在278.15~338.15 K温度范围内,样品的密度与其含水量呈很好线性关系。利用外推方法确定了含水量为零时[C5mim][BF4]的密度ρ,得到了密度随温度变化的经验方程:lnρ=0.120 11-5.79×10-4(T-298.15)和离子液体的热膨胀系数α=5.79×10-4K-1。根据Glasser理论估算了[C5mim][BF4]的标准熵、表面能和晶格能,晶格能较小使离子液体在室温下能以液态形式存在。利用空隙模型计算得到了[C5mim][BF4]热膨胀系数α(计算),与实验测定值在数量级上一致,说明空隙模型有一定的合理性。更多还原

【Abstract】 According to standard addition method a series of samples of known water-containing ionic liquid(IL) [C5mim] [BF4](1-methyl-3-pentylimidazolium tetrafluoroborate) were prepared and their densityexhibited a good linear relationship with the water content in a temperature range of278.15 to 338.15 K.Byextrapolation,the density values of the ionic liquid at various temperatures were determined.The empericalequation,lnρ=0.1201 1-5.79×10-4(T-298.15),and the thermal expansion coefficient of the IL,α=5.79×10-4K-1,were obtained.On the basis of Glasser′s theory,the standard molar entropy,the surfaceexcess energy,and crystal energy of the IL were estimated.In terms of the interstice model,the thermalexpansion coefficient of the IL,α(calculated),was calculated,which was in good agreement with the experi-mentalα.This result means that the interstice model is reasonable.更多还原