Olomukoro Aghogho A, Xie Ruichao, Paucar Fabiola X Fernandez, DeRosa Charlotte, Danielson Neil D, Gionfriddo Emanuela
Department of Chemistry and Biochemistry, The University of Toledo, Toledo, Ohio, USA.
Dr. Nina McClelland Laboratory for Water Chemistry and Environmental Analysis, The University of Toledo, Toledo, Ohio, USA.
J Sep Sci. 2024 Aug;47(16):e2400413. doi: 10.1002/jssc.202400413.
The ubiquitous presence and persistence of per- and polyfluoroalkyl substances (PFAS) in the environment have raised concerns in the scientific community. Current research efforts are prioritizing effective PFAS remediation through novel sorbents with orthogonal interaction mechanisms. Recognized sorption mechanisms between PFAS and sorbents include hydrophobic, electrostatic, and fluorine-fluorine interaction. The interplay of these mechanisms contributes significantly to improved sorption capacity and selectivity in PFAS separations. In this study, a primary/secondary amine-functionalized polystyrene-divinylbenzene (Sepra-WAX) polymer was modified to create a fluorinated WAX resin (Sepra-WAX-KelF-PEI). The synthesis intermediate (Sepra-WAX-KelF) was also tested to assess the improvement of the final product (Sepra-WAX-KelF-PEI). The adsorption capacity of Sepra-WAX, Sepra-WAX-KelF, and Sepra-WAX-KelF-PEI, and their interactions with PFAS were evaluated. The effect of pH, ionic strength, and organic solvents on PFAS sorption in aqueous solution was also investigated. The sorbents showed varied adsorption capacities for perfluorooctanoic acid, perfluoropentanoic acid, perfluoro-n-decanoic acid, and hexafluoropropylene oxide dimer acid, with the average extraction capacity of the four analytes being Sepra-WAX-KelF-PEI (523 mg/g) > Sepra-WAX (353 mg/g) > Sepra-WAX-KelF (220 mg/g). Sepra-WAX-KelF-PEI provided the highest adsorption capacity for all analytes tested, proving that the combination of electrostatic and hydrophobic/fluorophilic interactions is crucial for the effective preconcentration of PFAS and its future applications for PFAS remediation from aqueous solutions.
全氟和多氟烷基物质（PFAS）在环境中的普遍存在和持久性引起了科学界的关注。目前的研究工作优先通过具有正交相互作用机制的新型吸附剂来实现有效的PFAS修复。PFAS与吸附剂之间公认的吸附机制包括疏水作用、静电作用和氟-氟相互作用。这些机制的相互作用对提高PFAS分离中的吸附容量和选择性有显著贡献。在本研究中，对伯/仲胺官能化的聚苯乙烯-二乙烯基苯（Sepra-WAX）聚合物进行改性，以制备氟化WAX树脂（Sepra-WAX-KelF-PEI）。还对合成中间体（Sepra-WAX-KelF）进行了测试，以评估最终产物（Sepra-WAX-KelF-PEI）的改进情况。评估了Sepra-WAX、Sepra-WAX-KelF和Sepra-WAX-KelF-PEI的吸附容量及其与PFAS的相互作用。还研究了pH、离子强度和有机溶剂对水溶液中PFAS吸附的影响。这些吸附剂对全氟辛酸、全氟戊酸、全氟正癸酸和六氟环氧丙烷二聚酸表现出不同的吸附容量，四种分析物的平均萃取容量为Sepra-WAX-KelF-PEI（523 mg/g）>Sepra-WAX（353 mg/g）>Sepra-WAX-KelF（220 mg/g）。Sepra-WAX-KelF-PEI对所有测试分析物的吸附容量最高，证明静电作用与疏水/亲氟相互作用的结合对于PFAS的有效预富集及其未来从水溶液中修复PFAS的应用至关重要。
