Tang Wenjie, Wu Yue, Gao Tingting, Wei Yingqin, Zhou Guowei
Key Laboratory of Fine Chemicals in Universities of Shandong, School of Chemistry and Pharmaceutical Engineering, Qilu University of Technology (Shandong Academy of Sciences) Jinan 250353 Shandong People's Republic of China
RSC Adv. 2018 Sep 25;8(58):33217-33227. doi: 10.1039/c8ra07026a. eCollection 2018 Sep 24.
In the present work, leucoemeraldine-based hybrid porous polyanilines (LHPPs) have been synthesized by the Friedel-Crafts reaction of leucoemeraldine and octavinylsilsesquioxane (OVS) for Cr(vi) removal. The resulting LHPPs were characterized by Fourier transform infrared spectroscopy, powder X-ray diffraction, thermogravimetric analysis, scanning electron microscopy and N adsorption-desorption. The findings indiated that the LHPPs were amorphous, with apparent surface areas ( ) in the range of 147 to 388 m g and total volumes in the range of 0.13 to 0.44 cm g. Cr(vi) removal experiments displayed that the LHPPs exhibited highly efficient Cr(vi) removal performance. The maximum Cr(vi) removal capacity of LHPP-1 was 990.1 mg g at 308 K and pH 1, which is higher than those of other reported polyaniline-based adsorbents. The adsorption process was a spontaneous, endothermic and chemical adsorption process. The adsorption behavior agreed well with Langmuir models and pseudo second-order equations. X-ray photoelectron spectroscopy and Fourier transformed infrared (FTIR) spectroscopy analysis revealed that the highly efficient Cr(vi) removal performance can be mainly attributed to the existence of numerous amine and imine groups on the surface of the LHPPs; these can function as adsorption active sites for Cr(vi) removal through electrostatic adsorption and reduction to Cr(iii) under acidic conditions. Moreover, the LHPPs exhibited excellent adsorption selectivity for Cr(vi) despite the presence of other metal ions (K, Cu, Mn) and anions (NO , SO ). Therefore, the LHPPs have potential applications for Cr(vi) removal in industrial wastewater.
在本工作中，通过白翠玉色聚苯胺与八乙烯基倍半硅氧烷（OVS）的傅里德-克拉夫茨反应合成了基于白翠玉色聚苯胺的杂化多孔聚苯胺（LHPPs）用于去除Cr(Ⅵ)。通过傅里叶变换红外光谱、粉末X射线衍射、热重分析、扫描电子显微镜和N吸附-脱附对所得的LHPPs进行了表征。结果表明，LHPPs为无定形，表观表面积在147至388 m²/g范围内，总体积在0.13至0.44 cm³/g范围内。Cr(Ⅵ)去除实验表明，LHPPs表现出高效的Cr(Ⅵ)去除性能。LHPP-1在308 K和pH 1时的最大Cr(Ⅵ)去除容量为990.1 mg/g，高于其他报道的基于聚苯胺的吸附剂。吸附过程是一个自发、吸热的化学吸附过程。吸附行为与朗缪尔模型和伪二级方程吻合良好。X射线光电子能谱和傅里叶变换红外（FTIR）光谱分析表明，高效的Cr(Ⅵ)去除性能主要归因于LHPPs表面存在大量的胺基和亚胺基；这些基团可作为吸附活性位点，通过静电吸附和在酸性条件下还原为Cr(Ⅲ)来去除Cr(Ⅵ)。此外，尽管存在其他金属离子（K、Cu、Mn）和阴离子（NO₃⁻、SO₄²⁻），LHPPs对Cr(Ⅵ)仍表现出优异的吸附选择性。因此，LHPPs在工业废水中去除Cr(Ⅵ)方面具有潜在的应用价值。
