Abstract:

β-Cyclodextrin polymer（β-CDP）microspheres were synthesized from β-cyclodextrin（β-CD）by inverse emulsion polymerization with epichlorohydrin as a crosslinking agent. Thermodynamic and kinetic characteristics as well as adsorption mechanism of β-CDP microspheres for p-nitrophenol（p-NP）from aqueous solution were investigated. Static adsorption isotherms at different temperatures illustrated that adsorption of p-NP on β-CDP microspheres reached a balance after 2h. The adsorption fitted with the first- and second-order dynamic equations，and the correlation coefficients were 0.9915 and 0.9998，respectively. The Langmiur and the Freundlich adsorption isotherm equations were adapted for the adsorption characteristics of β-CDP microspheres for p-NP at temperatures of 298 K，318 K and 338 K. The enthalpy change（ΔH），free energy change（ΔG）and entropy change（ΔS）were all negative，and the adsorption was a spontaneous，endothermic and enthalpy promoting process.

摘要：

以β-环糊精（β-CD）为原料，环氧氯丙烷（ECH）为交联剂，采用反相乳液法得到β-环糊精聚合物（β-CDP）微球，探讨了水溶液中β-CDP微球对对硝基苯酚（p-NP）吸附的动力学、热力学特性及其机理，绘制了不同温度下的吸附等温线。结果表明：β-CDP微球对p-NP的吸附2 h后基本达到平衡，且与一级吸附动力学模型和二级吸附动力学模型都有较好拟合，相关系数分别为0.9915、0.9998；在298 K、318 K和338 K温度下符合Langmiur方程和Freundlich 方程；吸附焓变（ΔH）、熵变（ΔS）和吉布斯函变（ΔG）均为负值，吸附是焓推动作用，自发且过程放热。