Linker impact on the adsorption capacity of polyaspartate/montmorillonite composites towards methyl blue removal
Linker impact on the adsorption capacity of polyaspartate/montmorillonite composites towards methyl blue removal
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DOI：
10.1016/j.cej.2017.01.002
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发表时间：
2017-05-01
影响因子：
15.1
通讯作者：
Gemeay, Ali H.
中科院分区：
文献类型：
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作者：
Elsherbiny, Abeer S.;El-Hefnawy, Mohamed E.;Gemeay, Ali H.
在这项工作中，连接剂，如烷基季铵和烷基季鏻盐插入钠+ -蒙脱土（Na+-Mt）通过阳离子交换，然后与聚（琥珀酸酯-co-琥珀酰亚胺）作为生物降解和高吸水性聚合物的反应的效果进行了研究。采用元素分析、X射线衍射（XRD）、红外光谱（FT-IR）、扫描电镜（SEM）、透射电镜（TEM）、热重分析（TAG）和比表面积分析仪（BET）对复合材料进行了表征。与季铵盐型蒙脱土复合材料（Mt/IPS 1）相比，季铵盐型蒙脱土复合材料（Mt/IPS 2）具有更高的比表面积和孔容，这是由于其具有较大的结构。Mt/IPS 2复合材料对甲基蓝（MB）染料的最大吸附容量为9.95 mmol/g，大于Mt/IPS 1复合材料的8.55 mmol/g。吸附动力学数据进行了评估与伪一级，伪二级和颗粒内扩散模型。吸附平衡时间为20 min，吸附过程符合准二级动力学模型。在25、30和35 ℃下研究了亚甲基蓝在IPS 1和IPS 2上的吸附等温线，数据符合Langmuir等温模型。此外，热力学参数，即吉布斯自由能变化（Δ G（Ω）），焓变（Δ H-Ω），和熵变（Δ S-Ω）进行了计算和负Δ G（Ω）值表明该过程的自发性。通过红外光谱研究了吸附机理，提出了吸附剂表面阳离子活性中心与阴离子MB染料之间的静电相互作用。(C)2017爱思唯尔B. V.保留所有权利。
In this work, the effect of linkers such as alkyl quaternary ammonium and alkyl quaternary phosphonium salts intercalated with Na+ -montmorillonite (Na+-Mt) via cation exchange followed by the reaction with poly(aspartate-co-succinimide) as biodegradable and superabsorbent polymer has been investigated. The prepared composites were spectroscopically characterized by elemental analysis, X-ray diffraction (XRD), Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TAG), and Brunauer-Emmett-Teller (BET) surface analyzer. Polyaspartate-mentmorillonite composite with quaternary phosphonium salt (Mt/IPS2) exhibited higher surface area and pore volume compared with polyaspartate-montmorillonite composite with quaternary ammonium (Mt/IPS1), due to its bulky structure. Mt/IPS2 composite displays a maximum adsorption capacity of 9.95 mmol/g for methyl blue (MB) dye which is larger than Mt/IPS1 composite with 8.55 mmol/g. The kinetic data of adsorption were evaluated with pseudo first-order, pseudo second order and intra-particle diffusion models. The equilibrium time of 20 min toward MB adsorption and the pseudo-second-order was the best fit model for adsorption process. The adsorption isotherm of MB on the IPS1 and IPS2 has been investigated at 25, 30, and 35 C-omicron and the data were in good agreement with the Langmuir isotherm model. Furthermore, the thermodynamic parameters namely; Gibbs free energy change (Delta G(omicron)), enthalpy change (,Delta H-omicron), and entropy change (Delta S-omicron) were calculated and the negative Delta G(omicron) values indicate the spontaneity of the process. The adsorption mechanism was studied by FT-IR and the electrostatic interaction between cationic active sites of adsorbent surface and anionic MB dye was proposed. (C) 2017 Elsevier B.V. All rights reserved.