A facile synthesis of core-shell/bead-like poly (vinyl alcohol)/alginate@PAM with good adsorption capacity, high adaptability and stability towards Cu(Ⅱ) removal
A facile synthesis of core-shell/bead-like poly (vinyl alcohol)/alginate@PAM with good adsorption capacity, high adaptability and stability towards Cu(Ⅱ) removal
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DOI：
10.1016/j.cej.2018.06.129
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发表时间：
2018-11
影响因子：
15.1
通讯作者：
Wei Zhang-;Q. Deng;Qiulai He;Jianyang Song;Shilu Zhang;Hongyu Wang;Jinping Zhou;Huining Zhang
中科院分区：
文献类型：
--
作者：
Wei Zhang-;Q. Deng;Qiulai He;Jianyang Song;Shilu Zhang;Hongyu Wang;Jinping Zhou;Huining Zhang
通过将PAM交联到PVA/SA上，制备了一种用于重金属吸附的聚（乙烯醇）/海藻酸盐@聚丙烯酰胺（PVA/SA@PAM）的简便路线，由于核壳/珠状结构和聚合物共混的设计，它补充了天然和合成聚合物的优点。采用傅里叶变换红外(FT-IR)、扫描电子显微镜、能量色散X射线能谱(SEM-EDS)和X射线光电子能谱(XPS)等手段对合成的珠粒进行了表征。结果表明，最适pH值为5.0。 Cu(Ⅱ)的吸附过程符合Freundlich等温线模型和间歇系统准二阶模型。最佳条件下实验最大吸附容量为79.5±1.6mg/g，分别比普通SA珠和PVA/SA珠高约2.3和2倍。热力学研究表明吸附过程本质上是自发且吸热的。 Thomas模型比Bohart-Adams模型拟合得更好，在塔系统中不同初始Cu(Ⅱ)浓度下的突破曲线。更重要的是，PVA/SA@PAM表现出优异的机械稳定性和抗共存离子干扰的能力。此外，即使在可重复使用性测试中经过十一次循环后，其去除能力也仅略有下降。总体而言，PVA/SA@PAM具有生产工艺简单、成本低廉、吸附能力好、适应性强、化学机械稳定性好等优点。
A facile route of poly (vinyl alcohol)/alginate@ polyacrylamide (PVA/SA@PAM) for heavy metal adsorption was prepared by crosslinking with PAM onto PVA/SA, which complemented both benefits of natural and synthetic polymers, resulting from the design of core–shell/bead-like structure and polymer blending. Fourier transform infrared (FT-IR), scanning electron microscopy and energy-dispersive X-ray spectrometry (SEM-EDS) and X-ray photoelectron spectroscopy (XPS) etc. were applied to characterize as-synthesized beads. The results showed the optimal pH value was 5.0. The adsorption process of Cu(Ⅱ) fitted well with the Freundlich isotherm model and the pseudo-second-order model in batch system. The experimental maximum adsorption capacity was 79.5 ± 1.6 mg/g under the optimal condition, which is approximately 2.3 and 2 times higher than that of plain SA beads and PVA/SA beads, respectively. Thermodynamic studies revealed the adsorption process was spontaneous and endothermic in nature. Thomas model was fitted better than Bohart-Adams model with breakthrough curves under different initial Cu(Ⅱ) concentration in a column system. More importantly, the PVA/SA@PAM showed excellent mechanical stability and resistance for interference of co-existing ions. Besides, its removal ability only decreased slightly even after eleven cycles in reusability tests. Overall, PVA/SA@PAM exhibits attractive characteristics of simple production process, low cost, good adsorption capacity, excellent adaptability and chemical and mechanical stability.