聚乙二醇修饰ZIF-8的合成及对活性艳红的吸附

Synthesis of polyethylene glycol modified ZIF-8 and adsorption of reactive brilliant red

由于ZIF-8材料孔径较小,制约了其对大分子染料活性艳红的吸附,为了调节其孔径,结合有机膜制备中聚乙二醇(PEG)常作为孔调节剂,因此选择PEG作为软膜板剂对ZIF-8进行修饰复合,获得了一种新型的ZIF-8/PEG多孔纳米复合材料;采用XRD、SEM和氮气吸附-脱附等方法对ZIF-8/PEG进行表征。结果表明:合成了孔径有所增加的分级孔,形成了5~10 nm的介孔孔径,发现添加PEG改性后材料粒度变小,但比表面积不增反降,这是因为其介孔孔径的存在;考察了其对液相污染物偶氮废水——活性艳红X-3B的吸附性能,发现分子质量为2 ku的PEG改性其吸附量较未改性前提高26.7%,吸附量可达38.5 mg/g。

Due to the small pore diameter of ZIF-8 material,its adsorption to reactive brilliant red of macromolecular dyes is restricted.In order to adjust the aperture,considering that the polyethylene glycol(PEG)is often used as a pore regulator in the preparation of organic membranes,so PEG is selected as a soft diaphragm agent to modify ZIF-8,a new type of ZIF-8/PEG porous nanocomposite was obtained.XRD,SEM and nitrogen adsorption-desorption methods were used to characterize ZIF-8/PEG.The results show that the synthesized aperture increases the classification of hole,the mesoporous aperture of 5-10 nm was formed.It was found that the particle size of the material became smaller fater the addition of PEG,but the specific surface area did not increase but decreased because of the mesoporous pore diameter.The adsorption of azo wastewater-reactive brilliant red X-3B was investiated.It was found that the adsorption capacity of the modified PEG with a molecular weight of 2 ku was 26.7%higher that that before modification,and the adsorption capacity was up to 38.5 mg/g.