Water treatment and seawater desalination are two areas in which nanofiltration (NF) membranes have gained significant attention. The permeability and contamination resistance of NF membranes are crucial for their application in ion separation. Herein, a zwitterion monomeric N-sulfobutylpiperazine (PIPBS) was designed and synthesized through an in situ ring-opening reaction between 1,4-butylsulfonic acid lactone and piperazine. A new hydrophilic structure is formed when PIPBS is chemically grafted with piperazine-trimesoyl chloride (PIP-TMC) onto the surface of the NF membrane, increasing the water flux and improving antifouling properties. NF performance was systematically investigated with respect to both the PIPBS concentration and reaction time. In addition to higher salt retention for NaSO₄ (97.3%) and MgSO₄ (94.1%), the optimized PTPM also displayed better ion selectivity for Na₂SO₄/NaCl. Sulfonic acid groups make membranes more hydrophilic, reducing contamination, deposition, and membrane pore plugging by direct contact with contaminants. In comparison to untreated NF membranes, due to the hydration of PIPBS on the membrane surface, the water flux increased by 2.3 times with a 13.6% grafting ratio for PTPM-1. Furthermore, PTPM had superior protein fouling resistance and an excellent ability to recover flux after contamination experiments and could withstand continuous filtration operations for 60 h with a stable flux of 10.98 L m^–2 h^–1 bar^–1. The as-prepared NF membrane’s excellent water flux, selective rejection of salts, and outstanding fouling resistance make it ideal for efficient desalination, and it also provides novel insights into the design of antifouling membranes.

中文翻译：

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将缓冲层策略接枝到纳滤膜上，以增强防污性能，实现高效海水淡化


水处理和海水淡化是纳滤 （NF） 膜受到广泛关注的两个领域。NF 膜的渗透性和抗污染性对于其在离子分离中的应用至关重要。在此，通过 1,4-丁基磺酸内酯和哌嗪之间的原位开环反应设计合成了两性离子单体 N-磺基哌嗪 （PIPBS）。当 PIPBS 与哌嗪-三甲酰氯 （PIP-TMC） 化学接枝到 NF 膜表面时，会形成新的亲水结构，从而增加水通量并改善防污性能。系统研究了 PIPBS 浓度和反应时间方面的 NF 性能。除了对 NaSO₄ （97.3%） 和 MgSO₄ （94.1%） 具有更高的盐保留性外，优化的 PTPM 还对 Na₂SO₄/NaCl 表现出更好的离子选择性。磺酸基团使膜更具亲水性，减少直接接触污染物的污染、沉积和膜孔堵塞。与未处理的 NF 膜相比，由于 PIPBS 在膜表面的水合，PTPM-1 的水通量增加了 2.3 倍，接枝率为 13.6%。此外，PTPM 具有优异的抗蛋白质结垢性和出色的污染实验后回收通量的能力，可以承受 60 h 的连续过滤操作，稳定的通量为 10.98 L m^–2 h^–1 bar^–1。所制备的 NF 膜具有出色的水通量、选择性脱盐和出色的抗污染性，使其成为高效海水淡化的理想选择，它还为防污膜的设计提供了新的见解。