Synthesis Of Covalent Organic Framework Materials At Room Temperature And Atmospheric Pressure And Application Of Iodine Adsorption

Nuclear energy has many advantages than other sources of energy,such as it has the highest energy density and doesn't emit greenhouse gases.With many countries have plan to build their nuclear plants,immediate safety concerns are bringing out,for example how to disposal of nuclear waste products and how to rapidly collect the nuclear leakage products in some extreme circumstances like in Fukushima plant.Volatile radionuclides generate during nuclear fission process,such iodine,pose risk to the public safety and raises concerns about environmental pollution.Here,this article demonstrate a facile way to prepare a series of ultra-stable CN linked COFs(COF-Tpg DB,COF-Tpg BD and COF-Tpg Td)materials which effective capture and sequestration radionuclides iodine species.The main of thesis include the following aspects:In Chapter?,the current situation,design ideas and methods of covalent organic frameworks,as well as their characterization methods,the applications of photoelectric and catalytic were analyzed.In Chapter?,the covalent organic framework materials were synthesized at room temperature and atmospheric pressure,and characterized by polycrystalline X-ray diffraction,infrared spectroscopy,thermogravimetry and scanning electron microscopy,etc.In Chapter?,The adsorption experiments of iodine on covalent organic framework materials were carried out,and the adsorption of iodine and its ionic state on covalent organic framework materials was analyzed.The experimental results show that the covalent organic framework material has large effective specific surface area and strong stability.All of the three covalent organic framework materials show high iodine absorption rate,up to 2.6g/g(mass fraction 260%),which is due to the large surface area and functional groups of the covalent organic framework materials.Further analysis showed that the three covalent organic framework materials not only absorbed the traditional I2 molecule,but also absorbed the iodine in the ionic state(I3 – and I +).In this method,covalent organic framework materials were synthesized by aldol condensation at room temperature and atmospheric pressure,which is suitable for large-scale production.