氨基酸改性尼龙66纤维的制备及其铀吸附性能

采用辐射接枝法将甲基丙烯酸缩水甘油酯（GMA）接枝于尼龙66（PA66）纤维表面以引入环氧基团，利用N-乙酰-L-半胱氨酸（NAC）与环氧基团进行开环反应，制备出氨基酸改性的PA66纤维吸附材料。利用红外光谱、热重分析、X射线光电子能谱、扫描电镜对改性前后PA66纤维化学结构、表面形貌进行表征。考察了含铀水溶液的初始pH值、初始铀浓度和吸附时间对PA66纤维吸附材料的铀吸附容量影响规律。研究表明，当溶液初始pH为8时，铀吸附效果最佳；吸附时间为100 min时达到饱和吸附；吸附材料对铀的吸附符合准二级动力学模型和Langmuir等温吸附模型，吸附容量可达75.53 mg/g（铀初始质量浓度为25 mg/L）。此外纤维吸附材料在含铀等多种金属离子水溶液中具有良好的铀吸附选择性。

Preparation of Amino Acid Modified Nylon 66 Fiber and Evaluation of Its Uranium Adsorption Properties

Glycidyl methacrylate was grafted onto the surface of PA66 fiber using radiation-grafting method. Then, the ring-opening reaction between epoxy groups and N-acetyl-L-cysteine was carried out to prepare the amino acid modified PA66 functional fiber adsorbent. The chemical structures and surface morphologies of the pristine and graft-modified PA66 fibers were characterized by Fourier transformed infrared spectroscopy, thermogravimetric analysis,X-ray photoelectron spectroscopy and scanning electron microscopy, respectively. The effects of initial pH, initial uranium concentration and contact time on uranium adsorption performance of fiber adsorbent were investigated. The results show that the pH value of solution adjusted to 8 is conducive to the adsorption of uranium; the adsorption equilibrium reaches within 100 min; the uranyl ion adsorption process is in accordance with the pseudo-second-order kinetics model and the Langmuir isotherm adsorption model. The uranium adsorption capacity reaches 75.53 mg/g when the initial uranium mass concentration is 25 mg/L. Additionally, the fibers exhibits good adsorption selectivity for uranium in aqueous solution containing other metal ions.