β-环糊精交联聚合物吸附水中亚甲蓝的机理  

Study on the Adsorption of Methylene Blue With the β-cyclodextrin Crosslinked Polymer in the Water

作　　者：李国平[1] 吴晓萍[1] 黄泱[1] 陈建华[1] 

机构地区：[1]闽南师范大学化学与环境学院,福建漳州363000

出　　处：《华侨大学学报（自然科学版）》2015年第6期687-692,共6页Journal of Huaqiao University(Natural Science)

基　　金：国家自然科学基金资助项目(21076174);福建省教育厅科研项目(JA14199)

摘　　要：以氧化镁为致孔剂,利用环氧氯丙烷交联β-环糊精,合成多孔β-环糊精交联聚合物(β-CDP).考察β-CDP对亚甲蓝(MB)的吸附动力学、热力学讨论吸附的作用机理,并考察pH值、MB的初始质量浓度、吸附剂的投入量、吸附时间及吸附温度对β-CDP吸附MB的影响.结果表明:在室温下,水体的pH值为6.54,MB初始质量浓度为40mg·L-1,吸附剂投入量为0.6g·L-1,β-CDP的最大吸附量为62.6mg·L-1;吸附符合准二级吸附动力学模型和Freundlich等温吸附模型;结合颗粒内扩散模型,以及吸附热力学数据ΔH为20.50kJ·mol-1,ΔG为-6.1^-7.5kJ·mol-1,可得该吸附为异质表面的多因素联合控制物理吸附.β-eyclodextrin crosslinked polymer （β-CDP）was fabricated with the aid of magnesium oxide （MgO） as pore- foaming agent and epichlorohydrin as a crosslinker for β-cyclodextrin. Methylene blue （MB） adsorption on the surface of the β-CDP was proved by FT-IR, SEM and EDX. Then, the kinetics and thermodynamics of the adsorption of MB from aqueous solution onto the β-CDP was studied to explain the adsorption mechanism. Batch adsorption experiments were carried out to study the effects of solution pH, initial MB concentration, adsorbent dose, contact time and adsorption temperature on adsorption property. The results indicated that β-CDP presented the maximum MB uptake capacity of 62. 6 mg · L^-1 under the aqueous solution pH of 6. 54, adsorbent dose of 0. 6 g · L^-1, the initial MB concentration of 40 mg· L^-1 at room temperature. Kinetics experiments indicated that the pseudo-second-order model displayed the best cor- relation with adsorption kinetics data. And the isothermal adsorption was well described by Freundlich isotherm. Combine with the intra-particle model and the negative △G （-6. 1-7. 5 kJ · mol^-1） and positive AH （20. 5 kJ · mol^-1） obtained from van＇t Hoff equation, it could be discovered that the adsorption is a heterogeneous surfaces physical absorption with a multistep-controlling process.

关 键 词：Β-环糊精交联聚合物 吸附 亚甲蓝 动力学 热力学 

分 类 号：O661.1[理学—分析化学]