羟基铁柱撑蒙脱土制备过程热力学

Thermodynamics of Preparation Process of Hydroxy-Fe Pillared Montmorillonite

从热力学角度研究羟基铁在蒙脱土上的插层过程。羟基铁插层蒙脱土的平衡柱撑量与液相平衡浓度的关系符合Langmuir模型。实验条件下羟基铁插层蒙脱土是一个吸热、熵增加、自由能减少的柱撑过程,柱撑焓为17 646.5 J.mol-1,柱撑熵为67.7 J.K-1.mol-1,在40~80℃,柱撑自由能的数值为-3 553.8^-6 261.8 J.mol-1,由柱撑焓数值的大小推测羟基铁与蒙脱土为氢键结合。

The thermodynamics in the intercalation process of hydroxy-Fe on montmorillonite was investigated. The relationship between equilibrium pillared capacity of hydroxy-Fe on montmorillonite and liquid equilibrium concentration is Langmuir type. The intercalation of hydroxy-Fe on montmorillonite is endothermal,and entropy increased and free energy decreased with the pillared enthalpy of 17 646.5 J· mol^-1 ,the entropy of 67.7 J· K^-1. mol^-1 and the free energy range -3 553.8- -6 261.8J· mol^-1at temperature of 40-80℃. According to the value of pillared enthalpy,it can be speculated that the bonding force of hydroxy-Fe on montmorillonite is H-bonding.