Vamvakidis Kosmas, Kostitsi Theodora-Marianna, Makridis Antonis, Dendrinou-Samara Catherine
Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
Materials (Basel). 2020 Mar 27;13(7):1537. doi: 10.3390/ma13071537.
Water pollution by heavy metals is one of the most serious worldwide environmental issues. With a focus on copper(II) ions and copper complex removal, in the present study, ultra-small primary CoFeO magnetic nanoparticles (MNPs) coated with octadecylamine (ODA) of adequate magnetization were solvothermally prepared. The surface modification of the initial MNPs was adapted via three different chemical approaches based on amine and/or carboxylate functional groups: (i) the deposition of polyethylimide (PEI), (ii) covalent binding with diethylenetriaminepentaacetic acid (DTPA), and (iii) conjugation with both PEI and DTPA, respectively. FT-IR, TGA, and DLS measurements confirmed that PEI or/and DTPA were successfully functionalized. The percentage of the free amine (-NH) groups was also estimated. Increased magnetization values were found in case of PEI and DTPA-modified MNPs that stemmed from the adsorbed amine or oxygen ligands. Comparative UV-Vis studies for copper(II) ion removal from aqueous solutions were conducted, and the effect of time on the adsorption capacity was analyzed. The PEI-modified particles exhibited the highest adsorption capacity (164.2 mg/g) for copper(II) ions and followed the pseudo-second-order kinetics, while the polynuclear copper(II) complex Cu(DTPA) was also able to be immobilized. The nanoadsorbents were quickly isolated from the solution by magnetic separation and regenerated easily by acidic treatment.
重金属造成的水污染是全球最严重的环境问题之一。本研究聚焦于铜（II）离子和铜配合物的去除，通过溶剂热法制备了包覆有十八胺（ODA）且具有足够磁化强度的超小原生CoFeO磁性纳米颗粒（MNPs）。基于胺基和/或羧酸盐官能团，通过三种不同的化学方法对初始MNPs进行表面改性：（i）聚乙基酰亚胺（PEI）沉积，（ii）与二乙烯三胺五乙酸（DTPA）共价结合，以及（iii）分别与PEI和DTPA共轭。傅里叶变换红外光谱（FT-IR）、热重分析（TGA）和动态光散射（DLS）测量证实PEI或/和DTPA已成功功能化。还估算了游离胺基（-NH）的百分比。在PEI和DTPA改性的MNPs中发现磁化值增加，这源于吸附的胺或氧配体。进行了从水溶液中去除铜（II）离子的对比紫外可见光谱研究，并分析了时间对吸附容量的影响。PEI改性颗粒对铜（II）离子表现出最高吸附容量（164.2 mg/g），且遵循准二级动力学，同时多核铜（II）配合物Cu（DTPA）也能够被固定。通过磁分离可快速从溶液中分离出纳米吸附剂，并通过酸处理轻松再生。
