A piperazine derivative, N-aminoethyl piperazine (AEP) was utilized as the amine monomer to react with trimesoyl chloride (TMC) and to fabricate thin-film composite nanofiltration membranes via interfacial polymerization. Interestingly, AEP-TMC membranes with the oppositely charged surface have been obtained by simply regulating the mole ratio of AEP to TMC and the oppositely charged membranes performed quite different separation capabilities toward differently charged salts and dyes. For instance, the positively charged membrane (AEP/TMC = 240) presented a salt rejection in this order: MgCl₂>MgSO₄>Na₂SO₄>NaCl while the rejection order changed to: Na₂SO₄>MgSO₄>MgCl₂> NaCl for the membrane (AEP/TMC = 15) with a negatively charged surface. Meanwhile, the membranes also showed good water permeabilities (8.18 L m⁻² h⁻¹∙bar⁻¹ for AEP/TMC = 15 and 7.78 L m⁻² h⁻¹∙bar⁻¹ for AEP/TMC = 240). Besides, promising stabilities of the obtained AEP-TMC membranes were also confirmed via a 30-h continuous test with salt solutions and a 27-h cycled test with dye solutions. Considering the tunable surface and nanofiltration performance, together with the quite large commercially available resource of AEP, the resultant AEP-TMC TFC membrane presents great potential in further practical applications towards different charged components.

哌嗪衍生物N-氨基乙基哌嗪（AEP）被用作胺单体，与偏苯三甲酰氯（TMC）反应并通过界面聚合反应制备薄膜复合纳米过滤膜。有趣的是，已经通过简单地调节AEP与TMC的摩尔比获得了带相反电荷的表面的AEP-TMC膜，并且带有相反电荷的膜对带不同电荷的盐和染料具有完全不同的分离能力。例如，带正电的膜（AEP / TMC = 240）以此顺序排盐：MgCl ₂ > MgSO ₄ > Na ₂ SO ₄ > NaCl，而排阻顺序变为：Na ₂ SO ₄ > MgSO ₄> MgCl ₂ > NaCl用于带有负电荷表面的膜（AEP / TMC = 15）。同时，膜还显示出良好的水渗透率（8.18 L M ^-2  ħ ^-1 ∙巴^-1为AEP / TMC = 15和7.78 L M ^-2  ħ ^-1 ∙巴^-1（对于AEP / TMC = 240）。此外，还通过用盐溶液进行的30小时连续测试和使用染料溶液进行的27小时循环测试，也证实了所获得的AEP-TMC膜具有良好的稳定性。考虑到可调的表面和纳滤性能，以及相当大的AEP市售资源，所得的AEP-TMC TFC膜在针对不同带电组分的进一步实际应用中具有巨大的潜力。