Preparation Of Calix[4] Arene Sulfur Derivatives And Its Extraction Properties For U(?)

Nuclear energy,as an energy source for sustainable development,has been gained more and more attention.The vigorous development of energy was also accompanied by certain environmental problems.At present,the treatment of uranium-containing wastewater was an area of great concern.The p-tert-butyl calix[4]arene derivatives have been gradually applied to deal with environmental problems,because of its unique structural characteristics and easily modifying sites.In this paper,on the lower edge of the hydroxyl groups of p-tert-butyl calix[4]arene were chemically modified by p-tert-butyl calix[4]arene?1,2-dibromoethane?1,3-dibromopropane?potassium thioacetate and so on.Containing sulfur atom groups of a series of p-tert-butyl calix[4]arene derivatives were successfully synthesized and was characterized by FT-IR and NMR.The complexing properties of c₁?c₂?e₁ and e₂ on various metal ions were systematically analysed.The extraction efficiency of p-tert-butyl calix[4]arene derivatives with sulfur atom groups on simulated uranium containing wastewater were investigated in the presence of chloroform.The main research contents and conclusions of this paper are as follows:?1?The p-tert-butyl calix[4]arene was synthesized using formaldehyde and p-tert-butyl phenol as the raw material.Then,the compounds c₁?c₂?e₁ and e₂ were synthesized using 1,2-dibromoethane?1,3-dibromopropane?sodium sulfide nonahydrate and potassium thioacetate.?2?The compounds c₁?c₂?e₁ and e₂ were characterized by infrared spectroscopy?FT-IR?and nuclear magnetic resonance(¹³C NMR and ¹H NMR).The absorption peaks of derivatives were analysed by IR spectra data analysis,and the NMR spectra data further confirmed that the four compounds were all the target substances.?3?The complexation properties of four kinds of calix[4]arene sulfur derivatives?c₁?c₂?e₁?e₂?were analysed by UV-Vis spectroscopy.The compounds c₁?c₂?e₁ and e₂ had some complexation with eight kinds of metal ions(Cr³⁺?Mg²⁺?Ni²⁺?Ca²⁺?Pb²⁺?Na⁺?Co²⁺?UO₂²⁺),in which Ca²⁺and UO₂²⁺with compound c₁ and compound c₂ were complexed,the position of the absorption peak was changed and the intensity was enhanced.After the complexation of Co²⁺and Na⁺with the compound e₁,there was a more obvious red shift.?4?The effects of pH value,temperature and contact time on the U?VI?extraction with compounds c₁?c₂?e₁ and e₂ from aqueous solution were systematically investigated.The results showed that the optimum pH value for uranium extraction solution was about 4.5,and the extraction equilibration time was 90 min,and the temperature was 298 K.The extraction rate of four kinds of p-tert-butyl calix[4]arene containing sulfur derivatives gradually decreased with the increase of the temperature of the whole system,which indicated that the extraction reaction were exothermic reaction.?5?The effects of coexisting anions and cations(Na⁺?Pb²⁺?Mg²⁺?C₂O₄^-?SO₄^2-,etc.)on uranium extraction were investigated,and the multiple reverse extraction experiments were analysed.The results showed that the coexisting cations and anions had a certain effect on uranium extraction,and the cations were larger than the anions.The compound c₁?c₂?e₁ and e₂ still maintained a stripping rate of about 80%in that five times cyclic repeated experiments.