Baig Umair, Jillani Shehzada Muhammad Sajid, Waheed Abdul
Interdisciplinary Research Center for Membranes and Water Security, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia.
Membranes (Basel). 2023 May 19;13(5):528. doi: 10.3390/membranes13050528.
Given the huge potential of thin film composite (TFC) nanofiltration (NF) membranes for desalination and micro-pollutant removal, two different sets of six NF membranes were synthesized. The molecular structure of the polyamide active layer was tuned by using two different cross-linkers, terephthaloyl chloride (TPC) and trimesoyl chloride (TMC), reacted with tetra-amine solution containing β-Cyclodextrin (BCD). To further tune the structure of the active layers, the time duration of interfacial polymerization (IP) was varied from 1 to 3 min. The membranes were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), water contact angle (WCA), attenuated total reflectance Fourier transform infra-red (ATR-FTIR) spectroscopy, elemental mapping and energy dispersive (EDX) analysis. The six fabricated membranes were tested for their ability to reject divalent and monovalent ions followed by rejection of micro-pollutants (pharmaceuticals). Consequently, terephthaloyl chloride turned out to be the most effective crosslinker for the fabrication of membrane active layer with tetra-amine in the presence of β-Cyclodextrin using interfacial polymerization reaction for 1 min. The membrane fabricated using TPC crosslinker (BCD-TA-TPC@PSf) showed higher % rejection for divalent ions (NaSO = 93%; MgSO = 92%; MgCl = 91%; CaCl = 84%) and micro-pollutants (Caffeine = 88%; Sulfamethoxazole = 90%; Amitriptyline HCl = 92%; Loperamide HCl = 94%) compared to the membrane fabricated using TMC crosslinker (BCD-TA-TMC@PSf). For the BCD-TA-TPC@PSf membrane, the flux was increased from 8 LMH (L/m.h) to 36 LMH as the transmembrane pressure was increased from 5 bar to 25 bar.
鉴于薄膜复合（TFC）纳滤（NF）膜在海水淡化和微污染物去除方面的巨大潜力，合成了两组不同的六种NF膜。通过使用两种不同的交联剂对苯二甲酰氯（TPC）和均苯三甲酰氯（TMC）与含有β-环糊精（BCD）的四胺溶液反应，对聚酰胺活性层的分子结构进行了调整。为了进一步调整活性层的结构，界面聚合（IP）的持续时间从1分钟变化到3分钟。通过扫描电子显微镜（SEM）、原子力显微镜（AFM）、水接触角（WCA）、衰减全反射傅里叶变换红外（ATR-FTIR）光谱、元素映射和能量色散（EDX）分析对膜进行了表征。对制备的六种膜进行了二价和一价离子截留能力测试，随后测试了微污染物（药物）的截留能力。因此，在β-环糊精存在下，使用界面聚合反应1分钟，对苯二甲酰氯被证明是与四胺制备膜活性层最有效的交联剂。与使用TMC交联剂制备的膜（BCD-TA-TMC@PSf）相比，使用TPC交联剂制备的膜（BCD-TA-TPC@PSf）对二价离子（NaSO = 93%；MgSO = 92%；MgCl = 91%；CaCl = 84%）和微污染物（咖啡因 = 88%；磺胺甲恶唑 = 90%；盐酸阿米替林 = 92%；盐酸洛哌丁胺 = 94%）表现出更高的截留率%。对于BCD-TA-TPC@PSf膜，当跨膜压力从5巴增加到25巴时，通量从8 LMH（升/平方米·小时）增加到36 LMH。
