Non-solvent Induced Phase Separation Research Articles

Superhydrophobic poly(lactic acid) membrane prepared with the induction of modified carbon dots for efficient separation of water-in-oil emulsions

Superhydrophobic separation membranes are considered to be one of the most promising technologies for oil-water separation. However, the plastic waste generated from discarded membranes poses a challenge to the preparation of degraded superhydrophobic separation membranes for achieving eco-friendly separation. In this study, superhydrophobic poly(lactic acid) (PLA) membranes were fabricated using a non-solvent induced phase separation method assisted by l-cysteine modified carbon dots (Cys-CDs). The synergistic effect of Cys-CDs-induced crystallization behavior of PLA and the phase separation process results in the evolution of the surface of the PLA-based membrane from a pistil-like structure to a multi-level micro-nano structure composed of dense lamellar nanofibers and microspheres with an increase in Cys-CDs content. At a Cys-CDs content of 5 wt%, the surface roughness of PLA-based separation membrane reached its maximum, and the water contact angle was as high as 159°. Remarkably, the superhydrophobic Cys-CDs/PLA membrane exhibited promising performance in the separation of water-in-oil emulsions, with a rejection rate of 99.98 % and a flux of 315.74 L·m−2·h−1·bar−1. Additionally, the superhydrophobic Cys-CDs/PLA separation membrane also demonstrates impressive properties such as acid-alkali resistance and rapid recycling into high-value chemicals. Consequently, this rapidly recoverable superhydrophobic porous Cys-CDs/PLA membrane shows great potential for practical applications in actual oil-water separation.

Durable Superhydrophobic Coatings with Attapulgite for Inhibiting 5G Radome Rain Attenuation.

5G radomes are easily wetted and stained by rainfall, which greatly reduces the quality of signal transmission. Superhydrophobic coatings are expected to solve this problem because of their unique wettability, but it is still challenging to develop robust superhydrophobic coatings via simple methods. Here, we report the design of robust superhydrophobic coatings containing oxalic acid-modified attapulgite (MDP) for inhibiting rain attenuation of 5G radomes. First, a homogeneous suspension was prepared by nonsolvent-induced phase separation of a silicone-modified polyester adhesive (SMPA) solution containing fluorinated MDP (F-MDP) nanorods. Superhydrophobic coatings can be easily prepared by spraying the suspension. The effects of phase separation and the SMPA/F-MDP ratio on the surface morphology, superhydrophobicity, and stability of the coatings were systematically investigated. The micro-/nanostructure and low surface energy endow the coatings with excellent static and dynamic superhydrophobicity. Compared with previous studies, the coatings exhibit excellent mechanical stability, flexibility, chemical stability, and pressure resistance due to the combined effects of adhesion by SMPA, self-similar micro-/nanostructures, reinforcement by the MDP nanorods, etc. Consequently, the coatings show good performance in preventing rain attenuation of 5G radomes, an emerging application of Superhydrophobic coatings. We believe that the coatings have great application potential in various fields, including 5G communication.

Preparation of TA-O-MoS2/PES mixed matrix ultrafiltration membrane for rare earth wastewater treatment

The trade-off between permeability and selectivity, along with the issue of membrane fouling, has constrained the widespread application of ultrafiltration (UF) membranes in recycling rare earth wastewater. Here, we present the incorporation of tannic acid (TA) modified molybdenum disulfide oxide (O-MoS2) as a functional enhancer to fabricate polyethersulfone (PES) based mixed matrix membranes through a nonsolvent induced phase separation (NIPS) approach. Compared to the unmodified PES membrane, the integration of TA-O-MoS2 significantly improves the hydrophilicity, porosity in the mixed matrix membrane. By altering the concentration of TA-O-MoS2, the TA-O-MoS2/PES UF membrane achieves enhanced hydrophilicity and charge properties, resulting in a remarkable improvement in separation performance. Specifically, the optimized membrane M2 (TA-O-MoS2 addition of 0.1 wt%) exhibits a water flux of 140.98 Lm−2h−1bar−1 and a PEG 20000 rejection rate of 91.00 %, representing increases of 180 % and 120 % over the control PES membrane, respectively. Notably, membrane M2 effectively retains 91.31 % of macromolecular organic compounds in rare earth wastewater, while permitting nearly complete passage of inorganic salts, for instance CaCl2 (3.26 %) and MgSO4 (4.84 %). Moreover, the TA-O-MoS2/PES membrane demonstrates robust antifouling properties and exceptional durability, indicating its significant potential for efficient treatment and resource recovery in rare earth wastewater.

Synergistic effects of deep eutectic solvents on the morphology and performance of polysulfone ultrafiltration membranes

This study investigates the synthesis of flat sheet asymmetric Polysulfone (PSF) membranes using the Non-Solvent Induced Phase Separation (NIPS) method, enhanced by incorporating Deep Eutectic Solvents (DES) composed of Choline Chloride (ChCl) and DL-Malic Acid (MA). The research explores the individual and combined effects of ChCl and MA on membrane morphology and performance. Comprehensive characterization techniques, including Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy-Universal Attenuated Total Reflectance (FTIR-UATR), and Atomic Force Microscopy (AFM), were employed to analyze the structural and surface properties of the membranes. Key performance metrics such as Pure Water Permeability (PWP), protein and dye rejection, fouling behavior, porosity, surface hydrophilicity, and mechanical strength were evaluated. Results demonstrated that integrating DES into the PSF matrix significantly improved membrane properties. The 3% DES membrane exhibited the highest Pure Water Permeability (PWP) of 186.82 L/m2h/bar, the lowest water contact angle of 68.8°, and optimal balance in surface roughness parameters, leading to superior antifouling properties with high flux recovery ratio (FRR) and balanced reversible (Rr) and irreversible fouling (Rir) components. The ChCl (HBA) membrane displayed a notable PWP of 121.62 L/m2h/bar, large pore sizes (42.72 nm), and moderate surface roughness (Ra of 3.32 nm). In contrast, the MA (HBD) membrane demonstrated the highest hydrophilicity with the lowest contact angle (70.7°) and a compact, robust structure, despite its smallest pore sizes and lack of permeability. The findings underscore the synergistic effect of DES formation in the membrane, improving overall performance for ultrafiltration applications. This study provides valuable insights into the distinct roles of ChCl as an HBA and MA as an HBD in DES-modified PSF membranes, revealing their individual contributions and the importance of optimizing DES components and concentrations for specific filtration applications.

Preparation of Pressure-Resistant and Mechanically Durable Superhydrophobic Coatings via Non-Solvent Induced Phase Separation for Anti-Icing.

Inspired by the lotus leaf effect, superhydrophobic coatings have significant potential in various fields, However, their poor pressure resistance, weak mechanical durability, and complex preparation processes severely limit practical applications. Here, a method for preparing pressure-resistant and durable superhydrophobic coatings by simply spray-coating a phase separation suspension containing fluorinated silica nanoparticles and polyolefin adhesive onto substrates is introduced, which forms superhydrophobic coatings with a porous and hierarchical micro-/nanostructure. The resulting superhydrophobic coatings exhibit outstanding pressure resistance, maintaining a Cassie-Baxte state after 18 days of submersion in 1 m of water. Furthermore, the coatings demonstrate remarkable mechanical durability, withstanding 200 cycles of Taber abrasion, 100 cycles of tape-peeling, and 750g of sand abrasion. The coatings also show excellent chemical stability, enduring long-term immersion in corrosive liquids and 120 d of outdoor exposure. Additionally, the coatings display excellent anti-icing properties and can be applied to various substrate surfaces. This approach improves on the limitations of conventional superhydrophobic coatings and accelerates the application of superhydrophobic coatings in real-world environments.

Toward Predicting the Formation of Integral-Asymmetric, Isoporous Diblock Copolymer Membranes.

The self-assembly and nonsolvent-induced phase separation (SNIPS) process of block copolymers and solvents enables the fabrication of integral-asymmetric, isoporous membranes. An isoporous top layer is formed by evaporation-induced self-assembly (EISA) and imparts selectivity for ultrafiltration of functional macromolecules or water purification. This selective layer issupported by a macroporous bottom structure that is formed by nonsolvent-induced phase separation (NIPS) providing mechanical stability. Thereby the permeability/selectivity tradeoff is optimized. The SNIPS fabrication involves various physical phenomena-e.g.,evaporation, self-assembly, macrophase separation, vitrification - and multiple structural, thermodynamic, kinetic, and process parameters. Optimizing membrane properties and rationally designing fabrication processes is a challenge which particle simulation can significantly contribute to. Using large-scale particle simulations, it is observed that 1) a small incompatibility between matrix-forming block of the copolymer and nonsolvent, 2) a glassy arrest that occurs at a smaller polymer concentration, or 3) a higher dynamical contrast between polymer and solvent results in a finer, spongy substructure, whereas the opposite parameter choice gives rise to larger macropores with an elongated shape. These observations are confirmed by comparison to experiments on polystyrene (PS)-block-poly(4-vinylpyridine) (P4VP) diblock copolymer membranes, varying the chemical nature of the coagulant or the temperature of coagulationbath.

Eco-friendly, high-hydrophobic polybutylene succinate foam for oil-water separation

Polybutylene succinate (PBS) is an excellent biodegradable resin with good processability and toughness. The inherent hydrophobicity of this material makes it unique for the preparation of oil-water separation materials. In this paper, PBS foams with high hydrophobicity were prepared by the non-solvent induced phase separation (TINIPS) method using N, N-dimethylformamide (DMF) as a good solvent and anhydrous ethanol as a non-solvent. The effect of PBS concentration on the wettability and micro-morphology of this foam was experimentally investigated. The results showed that the foam had an optimal microporous structure with a water contact angle as high as 145° when the concentration of PBS was 30 %. It was further found that the saturated adsorption capacity of the foam was 5.55–12.39 times its mass and remained strong after 10 adsorption tests. Finally, the environmental adaptability of foams had been studied. The foams maintained their superhydrophobic and oil-absorbing properties in the presence of strong acids, strong bases, saturated sodium chloride solutions, and repeated abrasion. In addition, with the help of a pump-assisted adsorption device, oil-water mixtures can be separated continuously and quickly. This showed that the material had a broad application prospect in oil-water separation.

Nonsolvent-Induced Phase Separation pPAN Separators for Dendrite-Free Rechargeable Aluminum Batteries.

Rechargeable aluminum batteries (RAB) are a promising energy storage system with high safety, long cycle life, and low cost. However, the strong corrosiveness of chloroaluminate ionic liquid electrolytes (ILEs) severely limits the development of RAB separators. Herein, a nonsolvent-induced phase separation strategy was applied to fabricate the pPAN (poly(vinyl alcohol)-modified polyacrylonitrile) separator, which exhibits prominent chemical and electrochemical stability in ILEs. The pPAN separator, owing to its uniform pore size distribution and strong electronegativity with a zeta potential of about -10.20 mV, can effectively inhibit the growth of dendrites. Benefiting from the good ion conductivity (6.38 mS cm-1) and high ion migration number (0.133) of pPAN separator, the full cell with pPAN separator demonstrates stable operation for more than 500 cycles at 600 mA g-1, with a high capacity of 88.8 mAh g-1. When integrating into sodium-ion batteries, the pPAN separators also show an excellent electrochemical performance. This work provides a considerable approach for designing separators to address the issue of Al anode dendrite growth in RABs.

Polyacrylonitrile-blended polyethersulfone separator with greatly improved interface compatibility for lithium-oxygen battery

A novel polyacrylonitrile-blended/polyethersulfone (PES/PAN) separator was developed using the nonsolvent-induced phase separation (NIPS) method to improve the poor interfacial compatibility of Li-O2 batteries. Batteries assembled with the represented PES/PAN-2 separator exhibits significantly enhanced stability compared to the pristine PES separator. Its interfacial impedance (425.1 Ω) is one-fifth that of the pure PES separator (2018.1 Ω), while its ionic conductivity (0.70 mS cm−1) is nearly double that of the pristine PES (0.38 mS cm−1). With all these merits, the battery utilizing the PES/PAN-2 separator achieved excellent cycling performance of up to 80 cycles at 1000 mAh g−1, making it a superior choice for high-performance lithium-oxygen batteries.

Enhanced gravity-driven membrane filtration for purifying roof rainwater using multi-walled carbon nanotubes tuned PVDF hollow fiber membranes

The collection and reuse of roof rainwater can alleviate water shortage for daily life. In this study, polyvinylidene fluoride hollow fiber membranes tuned with three multi-walled carbon nanotubes (pure MWCNTs, MWCNTs-COOH, and MWCNTs-OH) were prepared using a non-solvent induced phase separation method for gravity-driven membrane filtration to purify roof rainwater. The results showed that the MWCNTs were distributed on the membrane surface and throughout the porous structure of the cross-section, which changed the pore structure parameters and hydrophilicity. The pure water flux of the MWCNTs tuned membranes increased by 152.5 % at 1.0 bar, and the rejection rates of humic acid and bovine serum albumin increased from 97.4 % and 75.7 % to 98.9 % and 96.3 %, respectively. The extended Derjaguin, Landau, Verwey, and Overbeek (xDLVO) theory states that the presence of MWCNTs leads to changes in the physicochemical properties of the membrane surface, resulting in membranes with different anti-fouling behaviors. A gravity-driven membrane filtration test was continuously operated for 100 days, and all membranes removed 25.0–26.7 %, 49.5–53.0 %, and 89.0–93.3 % of total dissolved solids, dissolved organic carbon, and turbidity from roof rainwater, respectively. However, the pure MWCNTs modified membrane with relatively hydrophobic properties showed a 12.4 % increase in flux over the unmodified membrane. Importantly, the presence of the MWCNTs in the membrane changed the microbial diversity in the biofilter cake layer.

Highly mechanically stable and intrinsically stretchable large-area organic photovoltaics using nanoporous bulk-heterojunction

It is important to develop bulk-heterojunction films that simultaneously exhibit good photovoltaic properties and mechanical robustness to realize intrinsically stretchable organic photovoltaics (IS-OPVs). We developed a strategy for preparing nanoporous bulk-heterojunction (np-BHJ) films at a large area by nonsolvent-induced phase separation assisted by thermoplastic polyurethane. The resulting np-BHJ can form much improved adhesive interfaces with a neighbored stretchable layer in OPV devices and effectively dissipate applied mechanical stress. IS-OPVs using the np-BHJ films showed efficiency of 12.0 %, which is comparable performance to 12.4 % of the controlled BHJ. The IS-OPV device using np-BHJ films much improved mechanical stability and maintained 89 % of its initial efficiency under applied strain of 40 %. The corresponding module showed only 10 % decrease in efficiency after 1,000 cycles in stretching tests at 10 % strain. Because of high scalability of the np-BHJ morphology, IS-OPV modules with efficiency of 7.06 % and active area of 10.17 cm2 and were successfully demonstrated. Photoplethysmography sensors prepared using the IS-OPV module showed strong potential for application in wearable electronics.

Additive-free preparation of hemodialysis membranes from silibinin-modified polysulfone polymer with enhanced performance in anti-oxidative stress and hemocompatibility

Oxidative stress is highly prevalent in maintenance hemodialysis patients and increases the risk of cardiovascular morbidity and mortality. Silibinin (SLB) is a plant extract with excellent antioxidant effects. The polymer of polysulfone (PSF) grafted SLB (PSF-g-SLB) was synthesized using a two-step approach, and the PSF-g-SLB membrane, a porogen-additive-free blood purification membranes made up of simply the polymer and solvent, was fabricated via the nonsolvent induced phase separation method. The results showed that, with increasing the grafting rate of PSF-g-SLB, the hydrophilicity, antioxidant properties, and the stability of free radical scavenging rate of the PSF-g-SLB membranes were improved. Furthermore, platelet-erythrocyte adhesion and hemolysis rate were decreased, and coagulation time was prolonged. The PSF-g-SLB membrane exhibits significant potential for being compatible with hemocompatibility, biocompatibility, and antioxidant properties. Therefore, the application of PSF-g-SLB membranes could alleviate oxidative stress in patients during hemodialysis.

Polymer‐Sorbent Direct Air Capture Contactors with Complex Geometries 3D‐Printed via Templated Phase Inversion

AbstractLow‐cost direct air capture (DAC) systems require efficient gas–solid contactors. These contactors provide rapid rates of heat and mass transport with minimal pressure drops. Triply periodic minimal surfaces (TPMS) are a class of geometries that are shown to have heat transfer properties that exceed those of other geometries, and these benefits are expected to manifest in mass transfer as well due to the analogies between heat and mass transfer. However, creating TPMS contactors is difficult using conventional manufacturing techniques such as injection molding. Non‐solvent‐induced phase separation (NIPS) of a polymeric ink containing the adsorbent is one way to construct adsorption contactors with excellent mass transport rates, but contactors have to date only been fabricated in simple geometries (e.g., films, fibers). This study demonstrates that NIPS of polymeric inks occurs within a simultaneously‐dissolving, water‐soluble, 3D‐printed template. This templated phase inversion (TPI) technique can create seemingly unlimited macroscopic architectures, including TPMS contactors, using a variety of potential DAC adsorbents, including zeolite, silica, activated carbon, and metal–organic frameworks. SEM, micro‐computed tomography, and nitrogen adsorption experiments reveal the microscopic pore structures and macroscopic geometries of the resulting sorbent contactors. TPMS DAC contactors with poly(ethyleneimine)/silica adsorbents are shown to have CO2 capture performances that rival or exceed other contactor geometries.

A Review on the Application of Deep Eutectic Solvents in Polymer-Based Membrane Preparation for Environmental Separation Technologies.

The use of deep eutectic solvents (DESs) for the preparation of polymer membranes for environmental separation technologies is comprehensively reviewed. DESs have been divided into five categories based on the hydrogen bond donor (HBD) and acceptor (HBA) that are involved in the production of the DESs, and a wide range of DESs' physicochemical characteristics, such as density, surface tension, viscosity, and melting temperature, are initially gathered. Furthermore, the most popular techniques for creating membranes have been demonstrated and discussed, with a focus on the non-solvent induced phase separation (NIPS) method. Additionally, a number of studies have been reported in which DESs were employed as pore formers, solvents, additives, or co-solvents, among other applications. The addition of DESs to the manufacturing process increased the presence of finger-like structures and macrovoids in the cross-section and, on numerous occasions, had a substantial impact on the overall porosity and pore size. Performance data were also gathered for membranes made for various separation technologies, such as ultrafiltration (UF) and nanofiltration (NF). Lastly, DESs provide various options for the functionalization of membranes, such as the creation of various liquid membrane types, with special focus on supported liquid membranes (SLMs) for decarbonization technologies, discussed in terms of permeability and selectivity of several gases, including CO2, N2, and CH4.

Preparation of a high performance PES/PES-OH Loose nanofiltration membrane based on reactive porogen

Loose nanofiltration membranes (LNF) have wide applications in the field of precise separation of small organic molecules. However, high separation precision of organic molecules with salts and a high water flux are still the challenges in the commercial applications of LNF membranes. In the current work, polyethersulfone (PES)/hydroxylated polyethersulfone (PES-OH) LNF membranes were synthesized by nonsolvent-induced phase separation (NIPS) based on reactive porogen (butyl dicarbonate, BDC) for the first time. The reactive porogen was decomposed to produce nanobubbles during heat-treated casting solution and phase inversion in HCl coagulation. It was found that the heat-treatment temperature of the casting solution was higher, the viscosity of the solution at 20 °C was higher due to the existence of more nanobubbles from BDC decomposition in the casting solution. Moreover, heat-treatment temperature had decisive impacts on the structure and separation property of the formed LNF membranes as nanobubbles actually acted as pore-forming agents. The HCl coagulation/immersion baths also promoted the BDC decomposition to produce the nanobubbles and improved the transmembrane water flux without sacrificing rejection and separation precision performance. The synthesized LNF membrane had a pore diameter approximately 3.81 nm, with a flux up to 200.2 L·m−2·h−1. Direct Black 38 shows a rejection of > 99 %, whereas NaCl shows a rejection of < 5 %, exhibiting a good separation accuracy and found superior to the separation performance in the literature. This research result has offered a novel approach for the preparation of superior performance LNF membranes, which can be utilized for precise separation.

The preparation technology and catalytic mechanism of PVDF/PVP/a-MoSx porous membrane for water flow driven piezoelectric PMS activation

Piezoelectric catalysis couples with peroxymonosulfate (PMS) activation technology can efficiently increase the yield of reactive oxygen species (ROS). Herein, a novel flexible polyvinylidene difluoride/polyvinyl pyrrolidone/amorphous molybdenum sulfide (PVDF/PVP/a-MoSx) membrane with finger-like pore structure was prepared by non-solvent induced phase separation (NIPS) method. As a result, a-MoSx nanosheets can be exposed out of the pores to provide multiple active sites. The PVDF/PVP/a-MoSx with large dipole moment can form enhanced polarization field under water flow to accelerate the charges separation and transfer, thereby promoting the breakage of the OO bond of PMS. The mechanism of piezo-photocatalytic activated PMS was confirmed by COMSOL multiphysics simulations, electrochemical experiments, contribution of active species and DFT calculations. Moreover, a self-cycling degradation reactor was proved more effective in generating piezoelectric potential and improving the degradation efficiency, supporting the practical potential of this strategy. This study provides a new platform to develop piezoelectric porous membrane for enhanced PMS activation under low density flow water energy.

BioMOF@PAN Mixed Matrix Membranes as Fast and Efficient Adsorbing Materials for Multiple Heavy Metals' Removal.

Heavy metal ions are a common source of water pollution. In this study, two novel membranes with biobased metal-organic frameworks (BioMOFs) embedded in a polyacrylonitrile matrix with tailored porosity were prepared via nonsolvent induced phase separation methods and designed to efficiently adsorb heavy metal ions from oligomineral water. Under optimized preparation conditions, stable membranes with high MOF loading up to 50 wt % and a cocontinuous sponge-like morphology and a high water permeability of 50-60 L m-2 h-1 bar-1 were obtained. The tortuous flow path in combination with a low water flow rate guarantees maximum contact time between the fluid and the MOFs, and thus a high heavy metal capture efficiency in a single pass. The performances of these BioMOF@PAN membranes were investigated in the dynamic regime for the simultaneous removal of Pb2+, Cd2+, and Hg2+ heavy metals from aqueous environments in the presence of common interfering ions. The new composite adsorbing membranes are capable of reducing the concentration of heavy metal pollutants in a single pass and at much higher efficiency than previously reported membranes. The enhanced performance of the mixed matrix membranes is attributed to the presence of multiple recognition sites which densely decorate the BioMOF channels: (i) the thioether groups, deriving from the S-methyl-l-cysteine and (S)-methionine amino acid residues, able to recognize and capture Pb2+ and Hg2+ ions and (ii) the oxygen atoms of the oxamate moieties, which preferentially interact with Cd2+ ions, as revealed by single crystal X-ray diffraction. The flexibility of the pore environments allows these sites to work synergically for the simultaneous capture of different metal ions. The stability of the membranes for a potential regeneration process, a key-factor for the effective feasibility of the process in real life applications, was also evaluated and confirmed less than 1% capacity loss in each cycle.

Effect of N-isopropylacrylamide and graphene oxide on the microstructure and performance of thermo-responsive membranes by Ce (IV)-induced redox radical polymerization

In this study, a series of novel thermo-responsive materials were synthesized using polyvinylidene fluoride, N-isopropylacrylamide (NIPAM) and graphene oxide (GO) via Ce (IV)-induced redox radical polymerization name as PNG. Thermo-responsive membranes were prepared by non-solvent induced phase separation. The results demonstrated that the CO and N-H stretching absorption intensities increased with the addition of NIPAM. XPS analysis demonstrated that the PNG1 membrane exhibited abundant functional group structure under the dosage of NIPAM at 1 g. The finger-like porous structure of membrane became longer and wider with the addition of NIPAM at 1 g, leading to a maximum porosity of 45.5 %. The CA decreased from 62.4 ° to 49.0 ° at 35 °C under the adding dosage of NIPAM at 1 g. The temperature-sensitive of PNG1 membrane was 35 °C. In addition, The PNG1 membrane had the lower Rir and higher flux recover than the others under the BSA rejection. According to the XDLVO theory analysis, the total interaction energy for PNG1 membrane achieved the maximum absolute values of −33.850 mJ/m2 and −19.956 mJ/m2 than the others under the temperature at 25 °C and 35 °C. This interaction influenced the adsorption between the pollutant and membrane surface, resulting in reversible fouling.

Quaternary phase-field simulation of the effect of additives on the structure of polyvinylidene fluoride microporous membranes

This study builds upon the existing phase-field model of the non-solvent-induced phase separation (NIPS) method, simulating factors that influence membrane formation in a ternary system. A polyvinylidene fluoride (PVDF) membrane system is utilized, and a fourth substance, an additive, is introduced based on the original mathematical model of the ternary system. The interaction parameters of the additives within the system are calculated using the Krevelen method. The simulation is configured to set the values of additive mobility and loss coefficients of the concentration gradient, thereby simulating the effect of additives in the quaternary system on the evolution of the micropore membrane structure. Finally, simulated images of different concentrations of additives with various types are compared with experimental results of microporous structure and porosity formation. This comparison serves to validate the model.

High-Performance Polyamidoxime Porous Membrane Prepared by the In Situ Modification/Nonsolvent-Induced Phase Separation Strategy for Uranium Extraction from Seawater.

The abundance of uranium (U(VI)) reserves in seawater makes it crucial to develop economically efficient methods for uranium extraction from seawater. In this work, an enhanced polyamidoxime porous membrane (PAOM) was fabricated by pre-in situ amidoxime modification combined with nonsolvent-induced phase separation (NIPS). The strategy of in situ modification of the polyacrylonitrile (PAN) solution served to enhance the homogeneity of the reaction and avoid the destruction of the membrane matrix and pore structure. Compared with the control sample (AOPM), PAOM possessed better mechanical strength and hydrophilicity. The introduction of polyvinylpyrrolidone (PVP) formed a porous structure in PAOM, improving spatial accessibility and facilitating the diffusion transport and capture of UO22+ inside the membrane. The more uniform and abundant distribution of amidoxime groups in PAOM gave it ultrahigh adsorption capacity and selectivity. The equilibrium adsorption capacity and Kd value of PAOM were 1.72 and 5.51 times higher than those of AOPM. Meanwhile, PAOM also demonstrated good recyclability, with only a 6.15% decrease in adsorption capacity after seven cycles. Additionally, PAOM exhibited excellent dynamic adsorption performance, and after 14 days of continuous filtration and adsorption, PAOM could extract 2.03 mg·g-1 U(VI) from natural seawater.