【摘要】 通过静态吸附实验 ,研究了NDA 15 0等 3种大孔吸附树脂对水溶液中山梨酸的吸附行为及其热力学性质。结果表明 ,山梨酸在 3种树脂上的吸附等温线均符合Freundlich等温吸附方程 ,且都表现为优惠吸附。在研究的浓度范围内 ,NDA 15 0的吸附能力约为CHA 111的 1 4～ 2 4倍和XAD 4的 2 1～ 4 0倍 ,树脂表面极性和微孔结构在吸附过程中起决定作用。吸附焓变ΔH <0且绝对值均小于 4 2kJ/mol,表明它们都属于放热的物理吸附过程。吸附自由能变ΔG表明 ,NDA 15 0具有更为优越的微孔结构。吸附熵变ΔS <0说明吸附质分子在吸附树脂表面上的运动相比溶液中受到更大的限制。更多还原

【Abstract】 The adsorption and thermodynamic behavior of sorbic acid in aqueous solution by three kinds of macroporous polymeric resins:NDA-150, CHA-111 and Amberlite XAD-4 have been investigated by static method. The results show that isotherm adsorption curves of sorbic acid by three polymeric resins all well fit to Freundlich adsorption isotherm equation. The adsorption capacities for sorbic acid on NDA-150 are 1.4～2.4 times and 2.1～4.0 times as high as that on CHA-111 and Amberlite XAD-4 respectively, due to the differences in surface polarity and micropore structure of the resins. The negative values of the adsorption enthalpy ΔH and the absolute values <42 kJ/mol indicate the exothermic physical adsorption character. The study on the free energy of adsorption manifests that there is a rather better pore structure in NDA-150. The negative values of the adsorption entropy ΔS indicate the more restricted mobility of the sorbic acid on the resin surface than in solution.更多还原