铕基金属有机框架材料从混合染料中选择性分离亚甲基蓝

利用紫外-可见吸收光谱和粉末X射线衍射等技术, 通过染料吸附实验、 混合染料吸附实验、 吸附动力学实验和循环吸附实验, 研究了一种铕基金属有机框架材料从混合染料水溶液中选择性分离亚甲基蓝的性能与机理. 研究结果表明, 该材料对亚甲基蓝的最大吸附量为20 mg/g, 在12 h内可完成对亚甲基蓝的选择性吸附, 且可以循环使用3次以上. 混合染料吸附实验结果表明, 该材料的吸附选择性源于孔道的静电作用与尺寸排斥效应.

Separating Methyl Blue Selectively from the Mixture of Dyes by Europium Metal-organic Frameworks

Although Eu-based metal-organic frameworks as fluorescence sensors have been reported widely， they are rarely used to separate dyes selectively owing to the lack of water stability. Herein， we choose a reported Eu-MOF to separate MB（methylene blue） selectively from mixed dyes aqueous by ion exchanges between the cations in the pore channels of the Eu-MOF and MB. The results show that MB can be separated selectively and quickly from the mixture of dyes. Meanwhile， the Eu-MOF not only has the relatedly high absorbing capacity of ca. 20 mg/g in aqueous solution at room temperature， but also can be recycled for 3 times at least. Moreover， the mechanism of highly selective absorption was also discussed， and as a consequence， the charge interaction and size exclusion play a key role in the absorption progress.