Preparation And Study Of Uranium Adsorption Properties Of Amidoximized Hyper Crosslinked Microporous Polymers

The extraction and removal of uranium from aqueous solution is of great significance in terms of sustainable utilization of uranium resources and environmental protection.In this experiment,we designed two kinds of hyper crosslinked microporous materials with the amidoxime group as the main adsorption group.The synthesized polymers have the advantages of high efficiency,low cost,high surface area,high adsorption capacity for uranyl ions,excellent selectivity and fast adsorption rate.A series of amidoxime-functionalized Scholl-coupling microporous polymers（SMPs-AO）were successfully prepared based on the Scholl reaction with the different molar ratio of 1,3,5-triphenylbenzene and phenylacetonitrile as initial reactants and Al Cl₃ as catalyst for the effectively extraction uranium from aqueous solution.The optimal uranium adsorption p H of the materials is 6.0,and the solid-liquid ratio is 0.2g/L.The analysis show that the SMP1 and SMPs-AO adsorption process belong to chemical adsorption and monolayer adsorption.Meanwhile,SMP3-AO shows the maximum sorption capacities,793.6 mg/g.The reusability and the adsorption behavior in the modified simulated seawater of the SMP3-AO is excellent.From XPS of SMP3-AO composites before and after capture uranyl ions,the adsorption is attributed to the oxygen and nitrogen atoms of amidoxime groups.A type of hyper crosslinked polymer（HCP-NH₂）was successfully prepared through one-step Friedel-Crafts alkylation reaction with benzene and benzylamine as initial reactants,anhydrous Fe Cl₃ as catalyst and a formaldehyde dimethyl acetal（FDA）as the external cross-linker for the effectively extraction uranium from aqueous solution.The amidoxime and amine-based bifunctional hyper crosslinked porous polymer HCPs-AO could be obtained by controlling the treatment time of sodium hypochlorite.p H=6 and 0.8 g/L were considered as the condition for future studies.And the analysis shows that the HCP-NH₂ and HCPs-AO adsorption process belongs to chemical adsorption.