Harbin Institute of Technology, Shenzhen; Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen, 518055, PR China.
Harbin Institute of Technology, Shenzhen; Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen, 518055, PR China.
Chemosphere. 2020 Jul;251:126384. doi: 10.1016/j.chemosphere.2020.126384. Epub 2020 Feb 29.
Aminosilane materials, with their low cost and ease of modification, have exhibited great potential for the adsorption of perfluorinated compounds (PFCs) from water. However, this kind of material may be facing two drawbacks during its application: low resistance to hydrolysis and difficulties in separation from the water matrix. This work proposed a strategy of grafting N-(2-aminoethyl) aminopropyltrimethoxysilane (AE-APTMS) on the surface of magnetic γ-FeO nanoparticles by full utilization of the sorption sites provided by the aminosilane and the magnetism by γ-FeO. The FTIR and XRD results verified the formation of the magnetic AE-APTMS nanocomposite. The core-shell nanocomposite showed a superparamagnetic property and an isoelectric point at pH = 8.2. Particularly, compared to the aminopropyltriethoxysilane (APTES) nanocomposite, the AE-APTMS nanocomposite exhibited improved hydrolytic stability with 60% less loss of the amine groups during the 48 h adsorption process, as the longer alkyl chain hindered the aminosilane detachment. The AE-APTMS nanocomposite exhibited a rapid adsorption with the removal efficiency of 78% for perfluorooctane sulfonate (PFOS) and 65% for perfluorooctanoate (PFOA) due to the electrostatic interaction and hydrophobic interaction. The regeneration and reuse of the magnetic AE-APTMS nanocomposite were conveniently realized with the removal efficiency higher than 70% for both PFOS and PFOA even after 15 adsorption-desorption cycles. The stable magnetic aminosilane nanocomposite with the ease of separation may provide a new strategy to achieve the economical and effective removal of typical PFCs from water.
氨基硅烷材料具有成本低、易修饰等优点，在吸附水中全氟化合物（PFCs）方面表现出巨大的潜力。然而，在应用过程中，这种材料可能面临两个缺点：水解稳定性差和难以与水基质分离。本工作提出了一种策略，通过充分利用氨基硅烷提供的吸附位点和 γ-FeO 的磁性，在磁性 γ-FeO 纳米颗粒表面接枝 N-(2-氨乙基)氨丙基三甲氧基硅烷（AE-APTMS）。FTIR 和 XRD 结果验证了磁性 AE-APTMS 纳米复合材料的形成。核壳纳米复合材料具有超顺磁性和等电点 pH=8.2。特别是与氨丙基三乙氧基硅烷（APTES）纳米复合材料相比，AE-APTMS 纳米复合材料在 48 h 吸附过程中表现出更好的水解稳定性，氨基损失减少了 60%，这是因为长烷基链阻碍了氨基硅烷的脱落。AE-APTMS 纳米复合材料具有快速吸附性能，对全氟辛烷磺酸（PFOS）和全氟辛酸（PFOA）的去除效率分别为 78%和 65%，这是由于静电相互作用和疏水相互作用。通过简便的再生和重复使用，磁性 AE-APTMS 纳米复合材料的去除效率均高于 70%，即使在 15 次吸附-解吸循环后，对于 PFOS 和 PFOA 也是如此。具有稳定磁性的易于分离的氨基硅烷纳米复合材料可能为从水中经济有效地去除典型 PFCs 提供了一种新策略。
