功能化间羧基苯偶氮基杯[4]芳烃对称硫醚衍生物的制备及其对U(Ⅵ)的吸附行为研究

Preparation of Functionalized m-carboxyphenyl Azo Calix[4]arene Symmetrical Sulfide Derivative and Its Adsorption Behavior towards U(Ⅵ)

采用间氨基苯甲酸为原料,经重氮化-偶联反应对杯[4]芳烃进行上沿改性合成了间羧基苯偶氮基杯[4]芳烃衍生物,再通过取代反应对间羧基苯偶氮基杯[4]芳烃衍生物进行下沿修饰,制备出一种新型材料,即间羧基苯偶氮基杯[4]芳烃对称硫醚衍生物,并采用FT-IR和~1H-NMR对其进行结构表征。将该新型材料作为吸附剂用于吸附低浓度含铀水溶液中的铀,考察了溶液pH值、吸附剂用量、铀初始浓度、吸附时间、吸附体系温度等因素对其吸附性能的影响。结果表明:在铀初始浓度为10 mg/L、pH=4、温度为25℃、吸附剂用量为10 mg、吸附平衡时间为4 h时,间羧基苯偶氮基杯[4]芳烃对称硫醚衍生物对U(Ⅵ)的吸附效果最佳;其吸附过程符合准二级动力学模型,吸附过程为化学吸附;吸附等温线符合Langmuir吸附等温模型,说明该吸附体系是以单层吸附为主。综上所述,间羧基苯偶氮基杯[4]芳烃对称硫醚衍生物是一种潜在的铀吸附剂。

Firstly, using m-aminobenzoic acid as raw material, m-carboxyphenyl azo calix[4]arene derivative was synthesized by upper-rim modification of calix[4]arene through diazotization-coupling reaction. Then, a new material called m-carboxyphenyl azo calix[4]arene symmetrical sulfide derivative was synthesized by substitution reaction. The new material was characterized by FT-IR and ~1H-NMR. It was used to adsorb U(Ⅵ) of the low concentration uranium-containing aqueous solution. The effects of initial pH, dosage of adsorbent, initial concentration of U(Ⅵ), time and temperature on the adsorption of U(Ⅵ) by the adsorbent were investigated. The results show that when the initial concentration of U(Ⅵ) is 10 mg/L, the initial pH is 4, the temperature is 25 ℃, the contact time is 4 h and the dosage of adsorbent is 10 mg, the adsorption effect of U(Ⅵ) by m-carboxyphenyl azo calix[4]arene symmetrical sulfide derivative is optimum. Its adsorption process conforms to the pseudo-second-order reaction kinetic model, indicating that the adsorption is chemisorption. Its adsorption isotherm is consistent with the Langmuir isotherm model, indicating that the adsorption system is based on single-layer adsorption. The above results indicate that m-carboxyphenyl azo calix[4]arene symmetrical sulfide derivative is a potential uranium adsorbent.