γ-CD-MOF-SH/CA复合材料对亚甲基蓝的吸附性能研究

Study on the adsorption performance of MOF/CA composite microsphere for MB

以海藻酸钠(SA)和硅烷偶联剂KH580修饰的改性环糊精金属有机框架材料(γ-CD-MOF-SH)为原料制备了改性环糊精金属有机框架/海藻酸钙(γ-CD-MOF-SH/CA)复合材料。采用接触角测定仪、傅里叶变换红外光谱仪、扫描电子显微镜、粉末X射线衍射仪及差示扫描量热仪对复合材料的结构和形貌进行表征,研究了其对废水中亚甲基蓝(MB)的吸附性能,考察了γ-CD-MOF-SH与SA质量比、pH及吸附温度对MB吸附量的影响,并进一步研究了吸附动力学和吸附等温线。结果表明:当γ-CD-MOF-SH与SA质量比为2、pH=11、温度为60℃时,复合材料吸附性能最佳。吸附过程符合准二级动力学和Langmuir等温模型,25℃时复合材料理论最大吸附量高达1202.78mg/g。该复合材料具有极好的重复利用性,循环第3次的吸附量为第1次吸附量的97.34%。

Sodium alginate(SA)and modified cyclodextrin-based metal organic framework(γ-CD-MOF-SH)modified by silane coupling agent KH580were used as raw materials to prepare MOF/CA gel microsphere composites.The structure and morphology of MOF/CA were characterized by contact angle meter,Fourier transform infrared spectrometer,scanning electron microscopy,powder X-ray diffraction and differential scanning calorimeter,and its adsorption performance for methylene blue(MB)in wastewater was studied.The effects of the mass ratio ofγ-CDMOF-SH to SA,pH and adsorption temperature on the adsorption capacity of MB were discussed,and further studied the adsorption kinetics and adsorption isotherms.The results showed that the adsorption performance was the best when the mass ratio ofγ-CD-MOF-SH to SA was 2,pH was 11,and temperature was 60℃.The adsorption process conformed to the pseudo-second-order kinetic model and the Langmuir model,and its theoretical maximum adsorption capacity was as high as 1202.78mg/g at 25℃.Besides,the microspheres exhibited excellent reusability,and its third adsorption capacity was 97.34%of the first adsorption capacity.