Li Juan, Yang Xiaodan, Bai Chiyao, Tian Yin, Li Bo, Zhang Shuang, Yang Xiaoyu, Ding Songdong, Xia Chuanqin, Tan Xinyu, Ma Lijian, Li Shoujian
College of Chemistry, Sichuan University, Key Laboratory of Radiation Physics & Technology (Sichuan University), Ministry of Education, Chengdu 610064, PR China.
College of Chemistry, Sichuan University, Key Laboratory of Radiation Physics & Technology (Sichuan University), Ministry of Education, Chengdu 610064, PR China.
J Colloid Interface Sci. 2015 Jan 1;437:211-218. doi: 10.1016/j.jcis.2014.09.046. Epub 2014 Sep 28.
A novel COF-based material (COF-COOH) containing large amounts of carboxylic groups was prepared for the first time by using a simple and effective one-step synthetic method, in which the cheap and commercially available raw materials, trimesoyl chloride and p-phenylenediamine, were used. The as-synthesized COF-COOH was modified with previously synthesized 2-(2,4-dihydroxyphenyl)-benzimidazole (HBI) by "grafting to" method, and a new solid-phase extractant (COF-HBI) with highly efficient sorption performance for uranium(VI) was consequently obtained. A series of characterizations demonstrated that COF-COOH and COF-HBI exhibited great thermostabilities and irradiation stabilities. Sorption behavior of the COF-based materials toward U(VI) was compared in simulated nuclear industrial effluent containing UO2(2+) and 11 undesired ions, and the UO2(2+) sorption amount of COF-HBI was 81 mg g(-1), accounting for approximately 58% of the total sorption amount, which was much higher than the sorption selectivity of COF-COOH to UO2(2+) (39%). Batch sorption experiment results indicated that the uranium(VI) sorption on COF-HBI was a pH dependent, rapid (sorption equilibrium was reached in 30 min), endothermic and spontaneous process. In the most favorable conditions, the equilibrium sorption capacity of the adsorbent for uranium could reach 211 mg g(-1).
首次采用简单有效的一步合成法制备了一种含有大量羧基的新型共价有机框架材料（COF-COOH），其中使用了廉价且市售的原料均苯三甲酰氯和对苯二胺。通过“接枝”法用先前合成的2-(2,4-二羟基苯基)苯并咪唑（HBI）对合成的COF-COOH进行改性，从而获得了一种对铀（VI）具有高效吸附性能的新型固相萃取剂（COF-HBI）。一系列表征表明，COF-COOH和COF-HBI表现出良好的热稳定性和辐照稳定性。在含有UO2(2+)和11种不需要离子的模拟核工业废水中比较了基于COF的材料对U(VI)的吸附行为，COF-HBI对UO2(2+)的吸附量为81 mg g(-1)，约占总吸附量的58%，远高于COF-COOH对UO2(2+)的吸附选择性（39%）。批量吸附实验结果表明，COF-HBI对铀（VI）的吸附是一个依赖于pH值、快速（30分钟内达到吸附平衡）、吸热且自发的过程。在最有利的条件下，吸附剂对铀的平衡吸附容量可达211 mg g(-1)。
