The Research Of Modified Metal-organic Frameworks Materials For Adsorption With U(Ⅵ)

With the rapid development of nuclear power, uranium demand surge, shortage of lan d resources of uranium was placed in front of people, and uranium from seawater is the onl y way to solve the shortage of nuclear fuel uranium.How to improve the extraction efficien cy, reduce extraction costs, the development of efficient, low-power, renewable sorbent is undoubtedly the key uranium from seawater.In light trigger photosensitive MOFs can be ac hieved under the guest molecule adsorption/release. Therefore, to light control uranium ads orption/release study is expected to achieve pollution-free, low energy consumption of ura nium from seawater. But so far not been reported light control uranium adsorption/release of relevant domestic and foreign, because so far there is no rational way to design a high of uranyl ion selective adsorption and efficient release of sensitive material. The project inten ds to carry out a photosensitive azobenzene Seawater System MOFs mention uranium, thro ugh molecular design, preparation of azobenzene different pore size flexibility and photose nsitive MOFs, using its optical control of uranium adsorption/release studies, which explai n the adsorption/release mechanism for low-energy seawater final solution to provide new i deas and detailed theoretical and experimental basis.Metal-organic frameworks(MOFs), as a new type of porous solids, have attracted extensive concerns of analytical chemistry owing to the high surface area, good thermal stability, chemical stability and so on. In this thesis,In this paper metal-organic frameworks as adsorbent materials,The main work is as follows:(1)Hydrothermal method was successfully used to synthesis Co +(para-phenylene +3) + azo polymers and zinc +(1, 4 ring + 3) + azo polymer.The XRD powder diffraction,infrared spectroscopy and scanning electron microscopy were used for Its structure.Statictest is discussed under the condition of different p H, temperature, adsorbent usage, ionic strength and the influence of adsorption time on the adsorption performance.(2) The results showed that the Co +(p-phenylene + 3) + azo polymer in p H = 4, 80 min adsorption time, initial concentration of uranium for 50 mg/L, on the adsorption capacity of uranium is 99.20 mg/g.Its adsorption performance of uranium is closely related to the acidity, high adsorption capacity under lower acidity, the adsorption equilibrium time is less than 120 min, the effect of ionic strength is bigger, has negative interference on adsorption.Isothermal adsorption model fitting results are mainly composed of monolayer adsorption, the theory of maximum adsorption capacity of 117.65 mg/g, quasi secondary dynamics model can better fit the adsorption process;(3) The results showed that the Co +(p-phenylene + 3) + azo polymer in p H = 4, 80 min adsorption time, initial concentration of uranium for 50 mg/L, on the adsorption capacity of uranium is 99.20 mg/g.Its adsorption performance of uranium is closely related to the acidity, high adsorption capacity under lower acidity, the adsorption equilibrium time is less than 120 min, the effect of ionic strength is bigger, has negative interference on adsorption.Isothermal adsorption model fitting results are mainly composed of monolayer adsorption, the theory of maximum adsorption capacity of 117.65 mg/g, quasi secondary dynamics model can better fit the adsorption process.