Perfluorooctanoic acid (PFOA) and its analogs, such as perfluorocaproic acid (PFHxA), perfluorobutyric acid (PFBA), and perfluoro(2-methyl-3-oxahexanoic) acid (GenX), present environmental contamination concerns due to their toxicity. To addressing this, in this study, we have explored the utility of thermoplastic polyurethane/polyethyleneimine (TPU/PEI) nanofibers, synthesized via electrospinning, for the efficient removal of PFOA and its analogs from aqueous solutions. Combining the positively charged amino groups of PEI and hydrophobicity of TPU potentially enhances adsorption. Further, the TPU/PEI nanofibers exhibit a distinctive nano-phase separation morphology, creating abundant adsorption sites conducive to PFAS binding. Batch adsorption experiments indicated that TPU/PEI nanofibers possess notable adsorption capacities for PFOA and its analogs. The observed adsorption capacities were ranked as follows: PFOA (0.931 mmol/g) > PFHxA (0.872 mmol/g) > PFBA (0.827 mmol/g) > GenX (0.771 mmol/g), thus showing a correlation with their respective octanol–water partition coefficient (Kow) values. Both inorganic ions and organic matter exerted more pronounced adverse effects on the adsorption of PFBA and GenX than on those of PFOA and PFHxA. This observation can be linked to competitive adsorption with PFAS. Impressively, the TPU/PEI nanofibers maintained a high removal efficiency across multiple regeneration cycles, with more than 95 % adsorption capacity retained after five cycles. To the best of our knowledge, this study is the inaugural demonstration of utilizing a TPU and PEI blend for remediation of both long-chain and short-chain PFAS in highly polluted wastewater, positioning it as a promising, accessible material for such applications.

中文翻译：

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用于有效去除 PFOA 及其类似物的 TPU/PEI 纳米纤维：pH 值、腐殖酸和共存离子的影响、机制和再生效应


全氟辛酸 （PFOA） 及其类似物，如全氟己酸 （PFHxA）、全氟丁酸 （PFBA） 和全氟（2-甲基-3-恶碳）酸 （GenX），由于其毒性而存在环境污染问题。为了解决这个问题，在这项研究中，我们探索了通过静电纺丝合成的热塑性聚氨酯/聚乙烯亚胺 （TPU/PEI） 纳米纤维在从水溶液中有效去除 PFOA 及其类似物的效用。结合 PEI 的带正电荷的氨基和 TPU 的疏水性可能会增强吸附。此外，TPU/PEI 纳米纤维表现出独特的纳米相分离形态，产生有利于 PFAS 结合的丰富吸附位点。批量吸附实验表明，TPU/PEI 纳米纤维对 PFOA 及其类似物具有显著的吸附能力。观察到的吸附容量排序如下：PFOA （0.931 mmol/g） > PFHxA （0.872 mmol/g） > PFBA （0.827 mmol/g） > GenX （0.771 mmol/g），因此与它们各自的辛醇-水分配系数 （Kow） 值呈相关性。无机离子和有机物对 PFBA 和 GenX 吸附的不利影响均比对 PFOA 和 PFHxA 的不利影响更明显。这一观察结果可能与 PFAS 的竞争性吸附有关。令人印象深刻的是，TPU/PEI 纳米纤维在多个再生循环中保持了高去除效率，在 5 个循环后仍保留了超过 95% 的吸附能力。据我们所知，这项研究是利用 TPU 和 PEI 混合物修复高污染废水中的长链和短链 PFAS 的首次演示，将其定位为此类应用的一种有前途、可获得的材料。