色谱 ›› 2021, Vol. 39 ›› Issue (9): 998-1005.DOI: 10.3724/SP.J.1123.2021.06016

• 研究论文 • 上一篇    下一篇

三聚氰胺功能化多孔有机聚合物的合成及其对甲基橙的吸附性能

张冲1, 郭云1, 彭子芳1, 张文芬1,*(), 张书胜2,*()   

  1. 1.郑州大学化学学院, 河南 郑州 450001
    2.郑州大学现代分析与基因测序中心, 河南 郑州 450001
  • 收稿日期:2021-06-09 出版日期:2021-09-08 发布日期:2021-09-06
  • 通讯作者: 张文芬,张书胜
  • 作者简介:Tel:(0371)67739689,E-mail: zsszz@126.com(张书胜).
    * Tel:(0371)67739689,E-mail: zhangwenfen1988@126.com(张文芬);
  • 基金资助:
    国家自然科学基金(21974124);国家自然科学基金(22004109);国家自然科学基金(22076174)

Preparation of melamine-functionalized porous organic polymer and its adsorption properties for methyl orange

ZHANG Chong1, GUO Yun1, PENG Zifang1, ZHANG Wenfen1,*(), ZHANG Shusheng2,*()   

  1. 1. College of Chemistry, Zhengzhou University, Zhengzhou 450001, China
    2. Center of Advanced Analysis and Gene Sequencing, Zhengzhou University, Zhengzhou 450001, China
  • Received:2021-06-09 Online:2021-09-08 Published:2021-09-06
  • Contact: ZHANG Wenfen,ZHANG Shusheng
  • Supported by:
    National Natural Science Foundation of China(21974124);National Natural Science Foundation of China(22004109);National Natural Science Foundation of China(22076174)

摘要:

首先以对三联苯(TP)和对苯二甲酰氯(TC)为单体合成了酮基聚合物前体(TP-TC),而后基于席夫碱反应将三聚氰胺(MA)与之交联得到胺功能化的多孔有机聚合物TP-TC-MA。通过扫描电镜(SEM)、透射电镜(TEM)、傅里叶变换红外光谱(FT-IR)、X射线衍射(XRD)、氮气吸附-脱附(BET)以及零电荷点(pHpzc)的测定等手段对合成的多孔有机聚合物进行表征。以染料废水中典型的阴离子染料甲基橙为研究对象,研究了TP-TC-MA对其吸附行为,并探讨了吸附机制。利用紫外-可见分光光度计(UV-Vis)得出目标污染物的紫外吸收光谱标准曲线,标准曲线拟合相关系数(R2)为0.999。结果表明,TP-TC-MA由于具有高比表面积(708.5 m2/g)和总孔体积(0.556 cm3/g)以及丰富的含氮基团,对阴离子染料甲基橙表现出优异的吸附性能。TP-TC-MA对水中甲基橙的吸附动力学符合准二级动力学方程,吸附平衡数据可以采用Langmuir等温吸附模型描述。经由Langmuir等温吸附模型计算得到的理论最大吸附容量为156.3 mg/g。选择性实验结果表明,TP-TC-MA对阴离子染料甲基橙具有更强的吸附作用,吸附作用机理可归结为静电相互作用、氢键和π-π相互作用等。在重复使用5次之后,TP-TC-MA对甲基橙仍保持90%以上的去除率,表明材料具有良好的稳定性和重复利用性,在染料废水处理中具有很好的应用前景。

关键词: 多孔有机聚合物, 席夫碱反应, 吸附, 三聚氰胺, 甲基橙

Abstract:

In this work, a polymer precursor was first synthesized using p-terphenyl (TP) and terephthaloyl chloride (TC) as monomers. Then, cross-linking was realized by means of a Schiff base reaction with melamine (MA) as a modifier to obtain an amine-functionalized porous organic polymer TP-TC-MA. The synthesized polymers were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), and point of zero charge (pHpzc) measurements, as well as on the basis of nitrogen adsorption-desorption isotherms. Adsorption experiments were carried out to evaluate the adsorption properties of TP-TC-MA for methyl orange (MO), a typical anionic azo dye that has widespread industrial application. The amount of MO adsorbed on TP-TC-MA was evaluated by ultraviolet-visible (UV-Vis) spectroscopy at a wavelength of 463 nm. Microscopic analysis revealed that the as-synthesized polymer had an aggregated particle-shaped structure. XRD spectra confirmed that TP-TC-MA was an amorphous polymer, consistent with the results of high-resolution TEM experiments. The Brunauer-Emmett-Teller (BET) specific surface area and total pore volume of TP-TC-MA were determined as 708.5 m 2/g and 0.556 cm3/g, respectively. The measured pHpzc of TP-TC-MA was 4.0, probably because of the abundant nitrogen-containing groups provided by MA. The factors affecting adsorption, such as pH, adsorbent dosage, contact time, initial pollutant concentration, and ionic strength, were investigated. Because of the protonation of the N-atom in TP-TC-MA, the pH had a strong impact on the adsorption of MO. The removal efficiency could be maximized at the optimized pH of 3.0. The adsorption equilibrium isotherm, measured at 25 ℃ and a concentration of 50-500 mg/L, showed that the MO adsorption over TP-TC-MA followed the Langmuir isotherm, with a maximum adsorption capacity of 156.3 mg/g. The modeling of the experimental adsorption data was consistent with the pseudo-second-order kinetic model, which indicated fast adsorption and chemisorption as the dominant mechanism. With increasing ionic strength, the adsorption of MO slightly decreased, suggesting a partial antagonistic ion effect. Results of the selectivity study revealed that TP-TC-MA was more selective toward MO than methylene blue (MB), which indicated that electrostatic interactions played a significant role during the adsorption progress. Five adsorption-desorption cycles showed that TP-TC-MA could be regenerated without significant deterioration of its adsorption efficiency, indicating that it has good stability and reusability. The observed adsorption performance indicated that this MA-modified porous organic polymer offers prospects for further research and application in the treatment of dye-containing wastewaters.

Key words: porous organic polymers, Schiff-base reaction, adsorption, melamine, methyl orange (MO)

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