Mandal Sujata, Kalaivanan Sandhya, Mandal Asit Baran
CLRI-Centre for Analysis, Testing, Evaluation & Reporting Services, CSIR-Central Leather Research Institute, Adyar, Chennai 600020, Tamil Nadu, India.
CSIR-Central Leather Research Institute, Adyar, Chennai 600020 Tamil Nadu, India.
ACS Omega. 2019 Feb 20;4(2):3745-3754. doi: 10.1021/acsomega.8b02743. eCollection 2019 Feb 28.
The present study aimed to improve the adsorption characteristics of the pristine layered double hydroxide (LDH) by physicochemical modification using polyethylene glycol (PEG), a nontoxic hydrophilic polymer. With this objective, LDH was synthesized and modified with different concentrations of PEG. The PEG-modified LDHs (LDH/PEGs) were characterized using X-ray diffraction, thermogravimetric analysis, Brunauer-Emmett-Teller surface area and porosity measurement, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and zeta potential measurements. The adsorption properties of the pristine LDH (PLDH) and the LDH/PEGs were studied for the removal of Acid Orange II from water, and the results were compared. The PLDH treated with 15% PEG solution showed ∼30% increase in adsorption capacity as compared to the PLDH. The adsorption isotherm data were analyzed using Langmuir, Freundlich, and Temkin isotherm models. The values of thermodynamic parameters such as Δ and Δ showed the spontaneous and endothermic nature of the adsorption process. The adsorption kinetics data for both PLDH and the LDH/PEG adsorbents presented a good fit to the pseudo-second-order kinetic model.
本研究旨在通过使用无毒亲水性聚合物聚乙二醇（PEG）进行物理化学改性来改善原始层状双氢氧化物（LDH）的吸附特性。为此，合成了LDH并用不同浓度的PEG进行改性。采用X射线衍射、热重分析、布鲁诺尔-埃米特-泰勒比表面积和孔隙率测量、扫描电子显微镜、透射电子显微镜、傅里叶变换红外光谱和zeta电位测量等方法对PEG改性的LDH（LDH/PEGs）进行了表征。研究了原始LDH（PLDH）和LDH/PEGs对水中酸性橙II的吸附性能，并对结果进行了比较。与PLDH相比，用15%PEG溶液处理的PLDH吸附容量提高了约30%。使用朗缪尔、弗伦德利希和坦金等温线模型对吸附等温线数据进行了分析。诸如Δ和Δ等热力学参数值表明吸附过程具有自发性和吸热性。PLDH和LDH/PEG吸附剂的吸附动力学数据均与准二级动力学模型拟合良好。
