物理化学学报 >> 2019, Vol. 35 >> Issue (3): 299-306.doi: 10.3866/PKU.WHXB201804172

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新型芳香三嗪超交联多孔聚合物去除水溶液中甲基橙

何妍1,2,*(),李豪1,周莉2,徐婷2,彭昌军2,*(),刘洪来2   

  1. 1 东华理工大学化学生物与材料科学学院,江西省聚合物微纳制造与器件重点实验室,南昌 330013
    2 华东理工大学化学系,化学工程国家重点实验室,上海 200237
  • 收稿日期:2018-03-15 录用日期:2018-04-10 发布日期:2018-08-28
  • 通讯作者: 何妍,彭昌军 E-mail:yanhe@ecit.edu.cn;cjpeng@ecust.edu.cn
  • 基金资助:
    国家自然科学基金(21476070);国家自然科学基金(21776069);国家重点基础研究发展计划(2015CB251401)

Removal of Methyl Orange from Aqueous Solutions by a Novel Hyper-Cross-Linked Aromatic Triazine Porous Polymer

Yan HE1,2,*(),Hao LI1,Li ZHOU2,Ting XU2,Changjun PENG2,*(),Honglai LIU2   

  1. 1 Jiangxi Province Key Laboratory of Polymer Micro/Nano Manufacturing and Devices, School of Chemistry, Biology and Materials Science, East China University of Technology, Nanchang 330013, P, R. China
    2 Key Laboratory for Advanced Materials, Department of Chemistry, East China University of Science and Technology, Shanghai 200237, P. R. China
  • Received:2018-03-15 Accepted:2018-04-10 Published:2018-08-28
  • Contact: Yan HE,Changjun PENG E-mail:yanhe@ecit.edu.cn;cjpeng@ecust.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(21476070);the National Natural Science Foundation of China(21776069);the National Key Basic Research Program of China(2015CB251401)

摘要:

有机染料,尤其是阳离子染料甲基橙(MO)是有毒有害的污染物之一,开发新型高效吸附剂去除MO具有重要意义。本文将含氮原子单体2, 4-二氨基-6-苯基-1, 3, 5-三嗪通过一步傅克烷基化法合成了一种新型芳香三嗪超交联多孔聚合物(HAPP)。利用扫描电镜(SEM)、透射电镜(TEM)、傅里叶变换红外(FTIR)光谱、元素分析(EA)、热重分析(TGA)、固体13C核磁共振(13C NMR)和N2吸附-脱附等温线表征了材料。结果表明,HAPP材料是表面不规则的粗糙无定型多孔有机聚合物,具有较高比表面积(104.4 m2∙g−1)和良好的热稳定性。HAPP对水溶液中的染料MO有很好的吸附效果,其对MO最大吸附容量(qmax)高达249.3 mg∙g−1,比之前一些文献报道的多孔材料MO吸附容量高。通过实验与理论计算相结合的方法详细讨论了HAPP高效吸附MO的吸附机理。5次吸附-脱附循环实验表明,HAPP对MO的去除率没有显著下降。

关键词: 超交联多孔聚合物, 一步法, 吸附, 甲基橙, 循环

Abstract:

Organic dyes, especially the harmful cationic dye methyl orange (MO), are emerging pollutants. The development of new materials for their efficient adsorption and removal is thus of great significance. Porous organic polymers (POPs) such as hyper-cross-linked polymers, covalent organic frameworks, conjugated microporous polymers, and polymers with intrinsic microporosity are a new class of materials constructed from organic molecular building blocks. To design POPs both with good porosity and task-specific functionalization is still a critical challenge. In this study, we have demonstrated a simple one-step method for the synthesis of the hyper-cross-linked aromatic triazine porous polymer (HAPP) via the Friedel-Crafts reaction. The resultant porous polymer was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, elemental analysis (EA), thermo-gravimetric analysis (TGA), solid-state 13C nuclear magnetic resonance (13C NMR), and nitrogen adsorption-desorption isotherms. The results show that HAPP is a rough, irregular morphology, porous organic polymer that is amorphous in nature. The novel polymer showed high Brunauer-Emmett-Teller surface area (of up to 104.36 m2∙g−1), porosity, and physicochemical stability. Owing to the presence of N heteroatom pore surfaces in the network, the material exhibited a maximum adsorption capacity of 249.3 mg∙g−1 for MO from aqueous solutions at room temperature. This is higher than that of some reported porous materials under the same conditions. To explain this phenomenon more clearly, theoretical quantum calculations were performed via the DFT method using Gaussian 09 software and Multiwfn version 3.4.1. It is performed to analyze the properties and electrostatic potential (ESP) of the HAPP monomer and MO. The results indicated that the N heteroatom of HAPP can easily develop strong interactions with MO, supporting the efficient adsorption of MO. The parameters studied include the physical and chemical properties of adsorption, pH, contact time, and initial concentrations. The percentage of MO removal increased as the pH was increased from 2 to 4. The optimum pH required for maximum adsorption was found to be 5.6. Adsorption kinetics data were modeled using the pseudo-first-order and pseudo-second-order models. The results indicate that the second-order model best describes the kinetic adsorption data. The adsorption isotherms revealed a good fit with the Langmuir model. More importantly, the HAPP can be regenerated effectively and recycled at least five times without significant loss of adsorption capacity. Therefore, it is believed that HAPPs with hierarchical porous structures, high surface areas, and physicochemical stability are promising candidates for the purification and treatment of dyes in solution.

Key words: Hyper-cross-linked porous polymer, One-step, Adsorption, Methyl orange, Regeneration