Department of Environmental Science and Engineering, State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Xi'an 710049, PR China.
Department of Environmental Science and Engineering, State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Xi'an 710049, PR China.
J Colloid Interface Sci. 2016 Aug 1;475:26-35. doi: 10.1016/j.jcis.2016.04.017. Epub 2016 Apr 22.
In this paper, the pure PPy and PPy/metal oxide composites including PPy/SiO2, PPy/Al2O3, and PPy/Fe3O4 as well as PPy coated commercial SiO2 and Al2O3 (PPy/SiO2(C) and PPy/Al2O3(C)) were successfully synthetized via chemical oxidative polymerization in acid aqueous medium to investigate the influence of metal oxides on adsorption capacity and their adsorption characteristics for Methylene Blue (MB). The composites were characterized by Zeta potential analysis, BET analysis, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA) and scanning electron microscope (SEM). The results indicate that the metal oxides have great impact on textural properties, morphology, Zeta potential and PPy polymerization on their surface, further influence the adsorption capacity of their composites. The PPy/Al2O3(C) composite owns the highest specific surface area, rougher surface and most PPy content, and show the highest monolayer adsorption capacity reaching 134.77mg/g. In the adsorption characteristic studies, isotherm investigation shows an affinity order of PPy/metal oxides of PPy/Al2O3(C)>PPy/Al2O3>PPy/SiO2(C)>PPy/SiO2>PPy/Fe3O4>PPy, stating the affinity between PPy and MB was greatly improved by metal oxide, and Al2O3 owns high affinity for MB, followed by SiO2 and Fe3O4. Kinetic data of the composites selected (PPy/SiO2(C), PPy/Al2O3(C) and PPy/Fe3O4) were described more appropriately by the pseudo-second-order model, and the order of K2 is PPy/Al2O3>PPy/SiO2>PPy/Fe3O4, further showing a fast adsorption and good affinity of PPy/Al2O3(C) for MB. The regeneration method by HCl-elution and NaOH-activation was available, and the composites selected still owned good adsorption and desorption efficiency after six adsorption-desorption cycles.
本文通过在酸性水介质中化学氧化聚合成功合成了纯聚吡咯（PPy）和包括 PPy/SiO2、PPy/Al2O3 和 PPy/Fe3O4 在内的金属氧化物复合材料以及商业 SiO2 和 Al2O3 涂覆的 PPy（PPy/SiO2(C) 和 PPy/Al2O3(C)），以研究金属氧化物对吸附能力的影响及其对亚甲基蓝（MB）的吸附特性。通过 Zeta 电位分析、BET 分析、X 射线衍射（XRD）、傅里叶变换红外光谱（FT-IR）、热重分析（TGA）和扫描电子显微镜（SEM）对复合材料进行了表征。结果表明，金属氧化物对其表面的结构性能、形态、Zeta 电位和 PPy 聚合有很大的影响，从而进一步影响了其复合材料的吸附能力。PPy/Al2O3(C) 复合材料具有最高的比表面积、更粗糙的表面和最多的 PPy 含量，表现出最高的单层吸附容量达到 134.77mg/g。在吸附特性研究中，等温线研究表明 PPy/金属氧化物的亲和顺序为 PPy/Al2O3(C)>PPy/Al2O3>PPy/SiO2(C)>PPy/SiO2>PPy/Fe3O4>PPy，表明 PPy 和 MB 之间的亲和力通过金属氧化物大大提高，Al2O3 对 MB 具有高亲和力，其次是 SiO2 和 Fe3O4。所选复合材料（PPy/SiO2(C)、PPy/Al2O3(C) 和 PPy/Fe3O4）的动力学数据更适合用伪二阶模型描述，K2 的顺序为 PPy/Al2O3>PPy/SiO2>PPy/Fe3O4，进一步表明 PPy/Al2O3(C) 对 MB 的快速吸附和良好亲和力。HCl 洗脱和 NaOH 活化的再生方法是可行的，所选复合材料在经过六次吸附-解吸循环后仍具有良好的吸附和解吸效率。
