Shuai Wang

Interfacial polymerization (IP) is widely used to prepare polyamide (PA) selective layer for thin-film composite (TFC) membranes, but achieving both high water permeability and ion selectivity in a single membrane remains challenging. Herein, we report a sodium lignosulfonate-regulated IP strategy to fabricate crumpled PA TFC membranes with enhanced water permeance and precise ion sieving. The introduction of sodium lignosulfonate (SL) into the aqueous phase promotes the partitioning of piperazine (PIP) into the organic phase, accelerating monomer supply near the interface, which drives the selective layer to evolve from a relatively smooth morphology into a pronounced ridge-and-valley crumpled structure. The crumpled architecture increases the effective mass-transfer area, while the sulfonate groups enhance membrane hydrophilicity and surface negativity. More importantly, regulation by SL leads to a narrower pore size distribution, with the geometric standard deviation reduced from 1.67 to 1.54. The optimized membrane achieves a high Cl-/SO2- 4 selectivity of 249.3 while maintaining a competitive pure water permeance of 14.9 L m-2 h-1 bar-1. This membrane also exhibits excellent antibiotic desalination performance, achieving a NaCl/tetracycline separation factor of up to 94.9, and enriching tetracycline by 2.2-fold in the feed after 12 h continuous filtration. This work provides an efficient strategy for constructing high-performance nanofiltration (NF) membranes with tunable crumpled structures for precise ion and molecular sieving.

Selective lithium recovery from highly acidic spent-battery leachates is constrained by the difficulty of achieving both membrane stability and precise ion discrimination under harsh chemical conditions. Here, we report a bioinspired adaptive ion nanochannels constructed from lysine-modified graphene oxide (Lys-GO) nanosheets for efficient Li+ recovery from acidic lithium-ion battery (LIB) leachates. Lysine acts as a multifunctional interfacial building block, simultaneously regulating sub-nanometer channel architecture, surface chemistry, and ion-transport behavior. Under concentrated HCl conditions, protonation of exposed amino groups creates a positively charged nanochannel environment that strengthens electrostatic exclusion of multivalent cations, while lysine carboxyl groups preferentially coordinate with Ni2+, Co2+, Mn2+, and Fe3+, imposing additional transport barriers. This coupled mechanism of acid-responsive charge regulation and ion-specific binding enables adaptive Li+/multivalent cation sieving in highly acidic media. In simulated spent-battery leachate containing 3 M HCl, the membrane delivers a high Li+/Ni2+ selectivity of 183.6 with a Li+ permeation rate of 0.48 mol m-2 h-1. This work establishes a bioinspired 2D membrane strategy that combines environmental responsiveness with ion-specific interactions for selective lithium recovery from acidic leachates and other harsh streams.

Membrane technology holds significant promise in the antibiotics desalination. However, its practical application is constrained by the limited controllability over membrane microstructures, including pore architecture and surface charge distribution. This study proposed a two-dimensional (2D) confined interfacial polymerization (IP) strategy to address the manipulability of the nanochannel morphology and the charge distribution for fabricating membrane with high performance of antibiotic desalination. The polyethyleneimine(PEI)-grafted amino-functionalized GO nanosheets were used as building blocks to construct ultra-thin 2D nanochannel membranes, further introduction of trimesoyl chloride (TMC) triggered the interface polymerization (IP) reaction within the confined space, which not only repairs the defects but also precisely regulates the charge distribution within the nanochannels. The optimized ultra-thin (only 48.6 nm thick) membrane existed more orderly interlayer channels and a nearly neutral charge distribution. These structural advantages yielded an unexpected antibiotics desalination performance with a water permeance of 176.2 L m-2 h-1 bar-1 and NaCl/tetracycline (TC) selectivity of 75.7 under the synergy of the enhanced size sieving and the eliminated electrostatic exclusion effect. Furthermore, this membrane demonstrated outstanding long-term stability. This study provides a scientific reference for developing high-performance membrane towards pharmaceutical industry and water purification.

Intelligent membranes with programmable permeance and precise sieving performance are in high demand for complex water treatment scenarios. Herein, a bioinspired membrane featuring intelligent adaptive 2D nanochannels with outstanding molecule sieving performance is reported. In particular, a protein‐mimetic 2D nanochannel with pH‐responsive characteristics is constructed by introducing sodium alginate (SA) molecular chains into GO laminates. The conformational transformation of SA chains under varying pH conditions enables adaptive regulation of the 2D channel size and selective molecular transport. The resulting GO‐SA membrane possesses outstanding water permeance up to 122.67 L m ⁻² h ⁻¹ bar ⁻¹ , along with a high sieving response factor of 50.12. Besides, it is discovered that the introduction of multivalent Ca ²⁺ ions can stabilize the membrane structure, thereby “locking” the pH‐responsive behavior. Based on this, the water treatment system is designed can not only realize the multistage separation of dye molecules, but also enable the recovery and recycling of acid and alkali. This strategy provides insights for designing intelligent membranes with gated responses.

Graphene oxide (GO) membranes are considered ideal candidates for efficient water treatment due to their unique two-dimensional structure and excellent sieving properties. However, the swelling of graphene oxide in aqueous solutions makes it still challenging for practical application. Inspired by the spider web, in this work, we developed a "network-trapped engineering" strategy to stabilize the interlayer spacings of GO membranes, which are defined as GS-Sr membranes. The sodium alginate (SA) and Sr2+ were successfully fixed as the "network" and "rivets" in-between the GO nanosheets, respectively. Benefiting from the design of the network structure, the GS-Sr membranes exhibited excellent interlayer spacing stability. Meanwhile, this evenly distributed network structure in the GO laminates can further optimize the stacking of nanosheets, forming more orderly 2D confined nanochannels. As a result, the membranes exhibited superior salt/dye sieving performance, with a separation factor up to 179.13 for Na2SO4/CR, while still maintaining an outstanding water permeance of 62.61 L m-2 h-1 bar-1 over 72 h (3 days). Furthermore, the enhanced thermal and mechanical stability of GS-Sr membrane was confirmed. Compared with traditional simple cross-linking strategies, this strategy offers a new insight into fine- construction of two-dimensional nanochannels.