β-环糊精改性多级孔纤维素膜的制备及其吸附性能

Preparation and adsorption properties ofβ-cyclodextrin modified porous cellulose membranes

为制备面向水体中微量污染物脱除的兼具高吸附容量和高吸附速率的理想型吸附剂,设计了一种多级孔高分子吸附膜,将β-环糊精(β-CD)通过硅烷偶联反应负载到大孔纤维素微滤膜表面。β-环糊精因具有外亲内疏的特性,可以与有机污染物分子形成包合物,为吸附作用的产生贡献活性吸附位点,而纤维素膜的大孔径能够为物质的传输提供对流传质通道,提高吸附速率。结果表明:通过简单的硅烷偶联反应将β-CD修饰再生纤维素微滤(RC)膜,制备出了具有介孔-大孔多级孔结构的RC-g-KHCD膜;吸附膜对苯酚的平衡吸附容量可到达0.130 mmol/g,对异丙甲草酸的平衡吸附容量可到达0.048 mmol/g,吸附热力学曲线符合Langmuir吸附模型,而吸附动力学曲线则符合膜扩散模型;再生重复使用测试进行10次后,吸附膜的再生效率仍然均达到90%以上,说明β-环糊精改性的纤维素膜是一种有效的吸附膜材料。

In order to prepare an ideal adsorbent with high adsorption capacity and high adsorption rate for the removal of trace pollutants from water,a hierarchical porous adsorption polymer membrane was designed,β-cyclodextrin(β-CD)was loaded onto the surface of macroporous cellulose microfiltration membrane through silane coupling reaction.Using the characteristics of hydrophilic outside hydrophobic and internal,β-CD formed inclusion complexes with organic pollutant molecules to provide active adsorption sites,while the macropore of cellulose membrane can provide mass transfer channels to improve the adsorption rate.The results show that RC-g-KHCD membrane with mesoporous and macroporous multistage structure is prepared by modifying RC membrane withβ-CD through simple silane coupling reaction.Upon phenol and removal of phenol and metolachlor in the water,the equilibrium adsorption capacity are 0.130 mmol/g and 0.048 mmol/g respectively.The adsorption isotherm can be described by the Langmuir model and the kinetic adsorption data fit very well with that of the film diffusion model.After 10 times of repeated use,the regeneration efficiency of the adsorption membrane can still reach more than 90%.It is concluded thatβ-cyclodextrin modified cellulose membrane is an effective adsorption membrane material.