School of Medical Instrument and Food Engineering, Shanghai Engineering Research Center for Food Rapid Detection, University of Shanghai for Science and Technology, P.O. Box 454, No. 516, Jungong Road, Shanghai, 200093, PR China.
School of Medical Instrument and Food Engineering, Shanghai Engineering Research Center for Food Rapid Detection, University of Shanghai for Science and Technology, P.O. Box 454, No. 516, Jungong Road, Shanghai, 200093, PR China.
Chemosphere. 2022 Feb;289:133086. doi: 10.1016/j.chemosphere.2021.133086. Epub 2021 Nov 27.
In this study, a novel eco-friendly porous double-network keratin/polyacrylic acid (keratin-PAA) hydrogel was prepared using the one-pot method to improve the adsorption performance of the hydrogel toward Pb(II). The obtained porous keratin-PAA hydrogel was then characterized using nitrogen adsorption-desorption isotherms, thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The interaction mechanism of Pb(II) and the keratin-PAA hydrogel was further investigated using X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). The results showed that keratin-PAA hydrogel was successfully synthesized, with a specific surface area of 49.35 m/g and a uniform pore distribution of 6.20 nm. The synthesized keratin-PAA hydrogel only took 6 min to adsorb nearly 70% of Pb(II) from the solution because of the interconnected porous network. The keratin-PAA hydrogel also showed a maximal adsorption amount of 234.6 mg/g, and satisfactory selectivity toward Pb(II). The adsorption kinetics of the keratin-PAA hydrogel binding to Pb(II) could be better described by the pseudo-second-order model, whereas the adsorption isotherms could be fitted using the Langmuir equation; this suggested that chemisorption was the main rate-limiting step. The XPS and FT-IR analysis results indicated that the sulfur-, nitrogen- and oxygen-containing groups in the keratin-PAA hydrogel were the main binding sites for Pb(II). In real aqueous samples, the keratin-PAA hydrogel could remove 93-104% of Pb(II). It is clear that the keratin-PAA hydrogel is an outstanding adsorbent material for the removal of Pb(II) from aqueous samples.
在这项研究中，使用一锅法制备了一种新型的环保多孔双网络角蛋白/聚丙烯酸（角蛋白-PAA）水凝胶，以提高水凝胶对 Pb(II) 的吸附性能。然后使用氮气吸附-解吸等温线、热重分析（TGA）和扫描电子显微镜（SEM）对所得多孔角蛋白-PAA 水凝胶进行了表征。进一步通过 X 射线光电子能谱（XPS）和傅里叶变换红外光谱（FTIR）研究了 Pb(II) 与角蛋白-PAA 水凝胶的相互作用机制。结果表明，角蛋白-PAA 水凝胶成功合成，比表面积为 49.35 m/g，孔径分布均匀，为 6.20 nm。由于互穿多孔网络的存在，合成的角蛋白-PAA 水凝胶仅需 6 分钟即可从溶液中吸附近 70%的 Pb(II)。角蛋白-PAA 水凝胶对 Pb(II) 的最大吸附量为 234.6 mg/g，且对 Pb(II) 具有良好的选择性。角蛋白-PAA 水凝胶与 Pb(II) 的吸附动力学可以更好地用伪二阶模型描述，而吸附等温线可以用 Langmuir 方程拟合；这表明化学吸附是主要的限速步骤。XPS 和 FT-IR 分析结果表明，角蛋白-PAA 水凝胶中的含硫、氮和含氧基团是与 Pb(II) 结合的主要位点。在实际水样中，角蛋白-PAA 水凝胶可以去除 93-104%的 Pb(II)。显然，角蛋白-PAA 水凝胶是一种从水样中去除 Pb(II) 的出色吸附材料。
