Ultrasound-assisted matrix solid-phase extraction based on deep eutectic solvents and zinc oxide: Extraction and determination of six active ingredients in Ligustri Lucidi Fructus.

In this study, we propose a novel strategy utilizing deep eutectic solvents (DESs) as both the extraction solvent and dispersing liquid, with nanometer zinc oxide (ZnO) serving as the adsorbent. This method incorporates ultrasound-assisted matrix solid phase dispersion (UA-MSPD) for the extraction of six active components (salidroside, echinacoside, acteoside, specnuezhenide, nuezhenoside G13, and oleanolic acid) from Ligustri Lucidi Fructus samples. The extracts were then analyzed using high-performance liquid chromatography equipped with a diode array detector. The effects of various parameters such as dispersant dosage, DESs volume, grinding time, ultrasonication duration, and eluent volume on extraction recovery were investigated and optimized using a central composite design under response surface methodology. The optimized conditions yielded detection limits ranging from 0.003 to 0.01 mg/g and relative standard deviations of 8.7% or lower. Extraction recoveries varied between 93% and 98%. The method demonstrated excellent linearity for the analytes (R2 ≥ 0.9997). The simple, green, and efficient DESs/ZnO-UA-MSPD technique proved to be rapid, accurate, and reliable for extracting and analyzing the six active ingredients in Ligustri Lucidi Fructus samples.

The Simultaneous Efficient Recovery of Ammonia Nitrogen and Phosphate Resources in the Form of Struvite: Optimization and Potential Applications for the Electrochemical Reduction of NO3.

In response to the need for improvement in the utilization of ammonium-rich solutions after the electrochemical reduction of nitrate (NO3--RR), this study combined phosphorus-containing wastewater and adopted the electrochemical precipitation method for the preparation of struvite (MAP) to simultaneously recover nitrogen and phosphorus resources. At a current density of 5 mA·cm-2 and an initial solution pH of 7.0, the recovery efficiencies for nitrogen and phosphorus can reach 47.15% and 88.66%, respectively. Under various experimental conditions, the generated struvite (MgNH4PO4·6H2O) exhibits a typical long prismatic structure. In solutions containing nitrate and nitrite, the coexisting ions have no significant effect on the final product, struvite. Finally, the characterization of the precipitate product by X-ray diffraction (XRD) revealed that its main component is struvite, with a high purity reaching 93.24%. Overall, this system can effectively recover ammonium nitrogen from the NO3--RR solution system after nitrate reduction, with certain application prospects for the recovery of ammonium nitrogen and phosphate.

Application Prospect of Ion-Imprinted Polymers in Harmless Treatment of Heavy Metal Wastewater.

With the rapid development of industry, the discharge of heavy metal-containing wastewater poses a significant threat to aquatic and terrestrial environments as well as human health. This paper provides a brief introduction to the basic principles of ion-imprinted polymer preparation and focuses on the interaction between template ions and functional monomers. We summarized the current research status on typical heavy metal ions, such as Cu(II), Ni(II), Cd(II), Hg(II), Pb(II), and Cr(VI), as well as metalloid metal ions of the As and Sb classes. Furthermore, it discusses recent advances in multi-ion-imprinted polymers. Finally, the paper addresses the challenges faced by ion-imprinted technology and explores its prospects for application.

Eligibility for elective surgery in patients recovering from mild COVID-19: A propensity-matched analysis.

OBJECTIVE: To study the timing of surgery after a recent Omicron variant infection, to provide a reference for policymakers, clinicians, and patients. METHODS: This single-center propensity-matched analysis was designed and reported according to the EQUATOR-STROBE guidelines. Patients recovering from COVID-19 infection were divided into three groups based on the period from disappearance of respiratory symptoms to surgery: ≤7 days, 8-14 days, and >14 days groups. Outcome measures included postoperative respiratory complications, vascular thrombosis, myocardial infarction, ischemic stroke, and mortality. RESULTS: Between August 1 and December 31, 2022, 9023 surgical procedures were performed, of which 7490 surgeries met the inclusion criteria. Propensity matching resulted in a final cohort of 227 patients recovered from COVID-19 and 2043 SARS-CoV-2 negative patients. Compared with the SARS-CoV-2 negative group, the incidence of postoperative respiratory complications was significantly higher (15.91% vs. 6.71%, p = 0.028) only in the ≤7 days group. There were no statistically significant differences in the other 30-day outcomes between the SARS-CoV-2 negative and the three COVID-19 recovery groups. CONCLUSIONS: Patients who have recovered from mild COVID-19 may be eligible for elective surgery at least 7 days after recovery, since they do not have an increased risk of postoperative complications or mortality within 30 days.

An Integrated Electrochemical System for Synergistic Cathodic Nitrate Reduction and Anodic Sulfite Oxidation.

Electrochemical reduction of nitrate has broad application prospects. However, in traditional electrochemical reduction of nitrate, the low value of oxygen produced by the anodic oxygen evolution reaction and the high overpotential limit its application. Seeking a more valuable and faster anodic reaction to form a cathode-anode integrated system with nitrate reaction can effectively accelerate the reaction rate of the cathode and anode, and improve the utilization of electrical energy. Sulfite, as a pollutant after wet desulfurization, has faster reaction kinetics in its oxidation reaction compared to the oxygen evolution reaction. Therefore, this study proposes an integrated cathodic nitrate reduction and anodic sulfite oxidation system. The effect of operating parameters (cathode potential, initial NO3--N concentration, and initial SO32--S concentration) on the integrated system was studied. Under the optimal operating parameters, the nitrate reduction rate in the integrated system reached 93.26% within 1 h, and the sulfite oxidation rate reached 94.64%. Compared with the nitrate reduction rate (91.26%) and sulfite oxidation rate (53.33%) in the separate system, the integrated system had a significant synergistic effect. This work provides a reference for solving nitrate and sulfite pollution, and promotes the application and development of electrochemical cathode-anode integrated technology.

Selective electrodialysis process for the recovery of potassium from multicomponent solution systems.

Selective electrodialysis is a promising approach to recovering K+ from complex coexisting ionic systems. In this study, the effects of current density, the concentration of K+ and Mg2+, as well as the operating temperature on the separation process of K+ and Mg2+ were explored to investigate the competitive migration of mono- and multivalent ions, offering a guide for the design of selective electrodialysis process, and therefore obtain the desired aqueous solutions containing K+ and Mg2+. The results show that ion concentration played a critical role in determining the selectivity of separation between K+ and Mg2+. High concentrations of K+ and Mg2+ led to a decrease in selectivity but the effect of concentration of K+ on selectivity was more pronounced. Although higher current density increased the flux of ions, their impact on separation selectivity was minimal. Furthermore, higher temperature increased the flux of ions but resulted in a decrease of K+ proportion in the solution. Overall, this study provides good guidance for studying the competitive migration of mono- and multivalent ions and the high-value recycling of potassium resources.

Study on the Structure of a Mixed KCl and K2SO4 Aqueous Solution Using a Modified X-ray Scattering Device, Raman Spectroscopy, and Molecular Dynamics Simulation.

The microstructure of a mixed KCl and K2SO4 aqueous solution was studied using X-ray scattering (XRS), Raman spectroscopy, and molecular dynamics simulation (MD). Reduced structure functions [F(Q)], reduced pair distribution functions [G(r)], Raman spectrum, and pair distribution functions (PDF) were obtained. The XRS results show that the main peak (r = 2.81 Å) of G(r) shifted to the right of the axis (r = 3.15 Å) with increased KCl and decreased K2SO4. The main peak was at r = 3.15 Å when the KCl concentration was 26.00% and the K2SO4 concentration was 0.00%. It is speculated that this phenomenon was caused by the main interaction changing, from K-OW (r = 2.80 Å) and OW-OW (r = 2.80 Å), to Cl−-OW (r = 3.14 Å) and K+-Cl− (r = 3.15 Å). According to the trend of the hydrogen bond structure in the Raman spectrum, when the concentration of KCl was high and K2SO4 was low, the destruction of the tetrahedral hydrogen bond network in the solution was more serious. This shows that the destruction strength of the anion to the hydrogen bond network structure in solution was Cl− > SO42−. In the MD simulations, the coordination number of OW-OW decreased with increasing KCl concentration, indicating that the tetrahedral hydrogen bond network was severely disrupted, which confirmed the results of the Raman spectroscopy. The hydration radius and coordination number of SO42− in the mixed solution were larger than Cl−, thus revealing the reason why the solubility of KCl in water was greater than that of K2SO4 at room temperature.

Inhibition of intracranial hemangioma growth and hemorrhage by TNFSF15.

Hemangioblastoma (HB) is an abnormal intracranial buildup of blood vessels that exhibit a great potential for hemorrhage. Surgical options are limited, and few medications are available for treatment. We show here by immunohistochemical analysis that HB lesions display highly increased levels of VEGF expression and macrophage/microglia infiltration compared with those in normal brain tissues. In the meantime, TNF superfamily 15 (TNFSF15) (also known as vascular endothelial growth inhibitor), an antiangiogenic cytokine, is highly expressed in normal brain blood vessels but diminished in HB lesions. We set up a brain hemangioma model by using mouse bEnd.3 cells of a T antigen-transformed endothelial cell line that produce a large amount of VEGF. When implanted in mouse brains, these cells form lesions that closely resemble the pathologic characteristics of HB. Retroviral infection of bEnd.3 cells with TNFSF15 leads to inhibition of VEGF production and retardation of hemangioma formation. Similar results are obtained when wild-type bEnd.3 cells are implanted in the brains of transgenic mice overexpressing TNFSF15. Additionally, TNFSF15 treatment results in enhanced pericyte coverage of the blood vessels in the lesions together with reduced inflammatory cell infiltration and decreased hemorrhage. These findings indicate that the ability of TNFSF15 to counterbalance the abnormally highly angiogenic and inflammatory potential of the microenvironment of HB is of therapeutic value for the treatment of this disease.-Yang, G.-L., Han, Z., Xiong, J., Wang, S., Wei, H., Qin, T.-T., Xiao, H., Liu, Y., Xu, L.-X., Qi, J.-W., Zhang, Z.-S., Jiang, R., Zhang, J., Li, L.-Y. Inhibition of intracranial hemangioma growth and hemorrhage by TNFSF15.

The effects of aperture position and length in side-vented needles on root canal irrigation: A computational fluid dynamics study.

INTRODUCTION: Root canal irrigation is crucial for infection control during root canal treatment. Side-vented needles for positive pressure irrigation are commonly used in clinical practice. However, variations in needle design among manufacturers can impact the fluid dynamics of irrigation. This study aims to use computational fluid dynamics to explore the flow characteristics of different needle aperture lengths and positions, and their effects on the effectiveness and safety of irrigation, using a validated passive scalar transport numerical model. METHODS: The validation of the CFD irrigant model was achieved by comparing it with an in vitro irrigation experiment model. The CFD model used scalar concentration, while the in vitro experiment model used red dye tracing. Using a standard 30G side-vented needle as a reference, virtual needle models featuring four aperture lengths and three positions were created. These virtual irrigation needles were then placed in two root canal geometries for CFD simulation to evaluate fluid exchange capabilities and related fluid dynamic parameters. RESULTS: The results of the CFD simulation, using a scalar transport model, closely matched the in vitro tracer tests for irrigation experiments across seven root canal geometries. The CFD analysis indicated that positioning the aperture lower increased the irrigant exchange distance. Notably, decreasing the aperture length to 0.25x, and positioning it at the lower end of the needle significantly increased exchange distance and shear stress, while reducing apical pressure. CONCLUSIONS: These results indicate that the position and length of the aperture affect the exchange distance of irrigant flow, wall shear stress, and apical pressure. The CFD validation model for scalar transport, based on a steady state, can function as a valuable tool for optimizing the side-vented needle in research. Further research on the design of side-vented needles will enhance the understanding of flow characteristics beneficial for irrigation efficiency in clinical practice.

A Study on the Reliability Evaluation of a 3D Packaging Storage Module under Temperature Cycling Ultimate Stress Conditions.

Based on the theory of reliability enhancement testing technology, this study used a variety of testing combinations and finite element simulations to analyze the stress-strain properties of 3D packaging storage modules and then evaluated its operating and destruction limits during temperature cycling tests (-65 °C~+150 °C) for the purpose of identifying the weak points and failure mechanisms affecting its reliability. As a result of temperature cycling ultimate stress, 3D packaging storage devices can suffer from thermal fatigue failure in the case of abrupt temperature changes. The cracks caused by the accumulation of plastic and creep strains can be considered the main factors. Crack formation is accelerated by the CTE difference between the epoxy resin and solder joints. Moreover, the finite element simulation results were essentially the same as the testing results, with a deviation occurring within 10%.

A Review of Fluoride Removal from Phosphorous Gypsum: A Quantitative Analysis via a Machine Learning Approach.

This review comprehensively explores fluoride removal from phosphogypsum, focusing on its composition, fluorine-containing compounds, characterization methods, and defluorination techniques. It initially outlines the elemental composition of phosphogypsum prevalent in major production regions and infers the presence of fluorine compounds based on these constituents. The study highlights X-ray photoelectron spectroscopy (XPS) as a pivotal method for characterizing fluorine compounds, emphasizing its capability to determine precise binding energies essential for identifying various fluorine species. Additionally, the first-principle density functional theory (DFT) is employed to estimate binding energies of different fluorine-containing compounds. Significant correlations are observed between the total atomic energy of binary fluorides (e.g., of alkali metals, earth metals, and boron group metals) and XPS binding energies. However, for complex compounds like calcium fluorophosphate, correlations with the calculated average atomic total energy are less direct. The review categorizes defluorination methods applied to phosphogypsum as physical, chemical, thermal, and thermal-combined processes, respectively. It introduces neural network machine learning (ML) technology to quantitatively analyze and optimize reported defluorination strategies. Simulation results indicate potential optimizations based on quantitative analyses of process conditions reported in the literature. This review provides a systematic approach to understanding the phosphogypsum composition, fluorine speciation, analytical methodologies, and effective defluorination strategies. The attempts of adopting DFT simulation and quantitative analysis using ML in optimization underscore its potential and feasibility in advancing the industrial phosphogypsum defluorination process.

Preparation of Fe/Co bimetallic oxide loaded hydrophobic & catalytic bifunctional membrane and its catalytic performance in sulfite oxidation.

Sulfite oxidation is critical for the stable operation of desulfurization process and the treatment & recovery of desulfurization by-products. The Fe and Co oxides modified super hydrophobic layer was prepared on tubular ceramic membranes using hydrothermal synthesis and surface modifications to realize the combination of the membrane catalysis and membrane aeration. These two oxides were approximately two-layer distributed on the membrane surface, among which the Fe2O3 located in the bottom layer and the Co3O4 located in the upper layer. The catalytic rate of the bifunctional membrane was about 5.8 times than that of the original ceramic membrane, which was decreased with the increasing of Fe/Co ratio and declined after an initial rise with the increase of urea and cetyltrimethylammonium bromide. The conjoint effect of Fe and Co could improve the catalytic performance and reduce the dissolution loss of catalyzer. The oxidation rate tended to be constant after a 15 % decrease in 7 times experiments.

Accelerated Diffusion of a Copper(I)-Functionalized COF Packed Bed Reactor for Efficient Continuous Flow Catalysis.

Flow chemistry provides a neo-orientation for the research and development of chemical technology, in which heterogeneous continuous catalysis based on packed beds can realize rapid separation and recycling. However, options for heterogeneous catalysts are still limited. In this work, we gradually grow covalent organic frameworks (COFs, TpBpy) on the surface of a silica gel (SiO2)-supported substrate to obtain a stable copper(I)-chelated high-loading heterogeneous catalyst (SiO2@CuI-TpBpy). SiO2@CuI-TpBpy shows high catalytic activity in three-component Huisgen 1,3-dipolar cycloaddition, giving the corresponding triazoles with excellent yields and reposeful recyclability under batch conditions. The structures of the catalysts remain steady, and the copper contents are basically unchanged after five cycles. Then, the catalysts are successfully applied for three-component heterogeneous catalysis in a one-pot continuous flow to prepare rufinamide in 89% yield for 24 h stably and efficiently with mere traces of copper ions remaining. More importantly, the catalytic system reveals a minuscule effect of catalyst particle size on internal diffusion. This COF encapsulation strategy presents a new possibility for the design of industrial heterogeneous catalysts with high metal loading and low internal diffusion resistance.

Comparative Investigation of the Microstructure of MgCl2 Aqueous Solutions Using Different X-ray Scattering Sources, Raman Spectroscopy, and Atomistic Simulations.

Aqueous solutions of magnesium chloride (MgCl2(aq)) are often used to test advances in the theory of electrolyte solutions because they are considered an ideal strong 2:1 electrolyte. However, there is evidence that some ion association occurs in these solutions, even at low concentrations. Even a small ion-pairing constant can have a significant impact on the chemical speciation of ions, so it is important to determine whether ion pairing actually occurs. In this study, MgCl2(aq) with concentrations ranging from 1 to 35% was studied using three methods: X-ray scattering (XRS) with the Shanghai Synchrotron Radiation Facility (SSRF) and silver-anode laboratory sources, Raman spectroscopy, and molecular dynamics (MD) simulations with the COMPASS-II and Madrid force fields. XRS results were analyzed in the framework of PDF theory to obtain the reduced structure function F(Q) and the reduced pair distribution function G(r). The F(Q) values from synchrotron radiation and laboratory sources both showed that the tetrahedral hydrogen bonds in bulk water were destroyed with the increased MgCl2 concentration. The results of G(r) indicated that the main peaks centered at 2.05 and 2.80 Å can be ascribed to the interactions of Mg-O and O-O, respectively. The peak at 3.10 Å is attributed to the combined effect of O-O and Cl-O. By comparing the structural information on MgCl2 solution obtained from the two light sources, it was found that both SSRF and silver-anode laboratory sources can reflect the above-mentioned structural information on MgCl2 solution. The radial distribution function (RDF) obtained from MD simulations of MgCl2 solutions assigned the peaks at 2.0, 2.8, and 3.2 Å to the Mg-O, O-O, and Cl-O interatomic pairs, respectively. The decrease in the O-O coordination number confirms that the hydrogen-bonding network of water is disrupted by increasing MgCl2 observed by X-ray scattering. The proportion of Mg-Cl contact ion pairs gradually increases with MgCl2 concentration as does the coordination number. Raman spectroscopy results show that the bond type changes from double donor double acceptor (DDAA) to single donor-single acceptor (DA) with increasing concentration, providing explicit details of the hydrogen-bond evolution in the aqueous solution.

Passive Electrical Components Based on Cotton Fabric Decorated with Iron Oxides Microfibers: The Influence of Static and Pulsed Magnetic Fields on the Equivalent Electrical Properties.

In this work, environmentally friendly and low-cost passive electrical components (PECs) are manufactured based on composites consisting of cotton fabrics soaked with solutions of silicone oil and different amounts of iron oxides microfibers (µFe). The µFe consists of a mixture of three phases: hematite (α-Fe2O3), maghemite (γ-Fe2O3), and magnetite (Fe3O4). The equivalent electrical capacitance (Cp) and resistance (Rp) of PECs are measured as a function of magnetic flux density B in a static and pulsed magnetic field superimposed on an alternating electric field of frequency 1 kHz. The relative variation in the hysteresis curves for both Cp and Rp are obtained by measuring them in the ascending and then the descending mode of B. We show that all these three quantities are sensibly influenced by the volume fractions of µFe and by the values of B. The main influence on this behavior is attributed to the semiconductor properties of the α-Fe2O3 and γ-Fe2O3 components of the oxide microfibers. In addition, it is found that at B≃ 175 mT, the maximum relative variance of the hysteresis curve is about 3.35% for Cp and 3.18 % for Rp. When a pulsed magnetic field is used, it is shown that Cp and Rp closely follow the variation in the magnetic field. Thus, the resulting electrical properties of PECs, together with the fast response to the application of pulsed magnetic fields, make them useful in the fabrication of various devices, such as electric, magnetic, and deformation fields, or mechanical stress sensors with applications in protection against electromagnetic smog, healthcare monitoring, or for human-machine interfacing.

Nondestructive monitoring of annealing and chemical-mechanical planarization behavior using ellipsometry and deep learning.

The Cu-filling process in through-silicon via (TSV-Cu) is a key technology for chip stacking and three-dimensional vertical packaging. During this process, defects resulting from chemical-mechanical planarization (CMP) and annealing severely affect the reliability of the chips. Traditional methods of defect characterization are destructive and cumbersome. In this study, a new defect inspection method was developed using Mueller matrix spectroscopic ellipsometry. TSV-Cu with a 3-µm-diameter and 8-µm-deep Cu filling showed three typical types of characteristics: overdishing (defect-OD), protrusion (defect-P), and defect-free. The process dimension for each defect was 13 nm. First, the three typical defects caused by CMP and annealing were investigated. With single-channel deep learning and a Mueller matrix element (MME), the TSV-Cu defect types could be distinguished with an accuracy rate of 99.94%. Next, seven effective MMEs were used as independent channels in the artificial neural network to quantify the height variation in the Cu filling in the z-direction. The accuracy rate was 98.92% after training, and the recognition accuracy reached 1 nm. The proposed approach rapidly and nondestructively evaluates the annealing bonding performance of CMP processes, which can improve the reliability of high-density integration.

Rheological Characteristics of Starch-Based Biodegradable Blends.

Thermoplastic starch was blended with commercially available biodegradable polyesters of poly(butylene adipate-co-terephthalate) (PBAT) and poly(lactic acid) (PLA) for its improved performance and processability. The morphology and elemental composition of these biodegradable polymer blends were observed by scanning electron microscopy and energy dispersive X-ray spectroscopy, respectively, while their thermal properties were analyzed using thermogravimetric analysis and differential thermal calorimetry. For rheological analysis, the steady shear and dynamic oscillation tests of three samples at various temperatures were investigated using a rotational rheometer. All three samples exhibited significant shear thinning at all measured temperatures, and their shear viscosity behavior was plotted using the Carreau model. The frequency sweep tests showed that the thermoplastic starch sample exhibited a solid state at all temperatures tested, whereas both starch/PBAT and starch/PBAT/PLA blend samples exhibited viscoelastic liquid behavior after the melting temperature such that their loss modulus at low frequencies was greater than the storage modulus, and inversion occurred at high frequencies (storage modulus > loss modulus).

Mechanical Behavior and Constitutive Model Characterization of Optically Clear Adhesive in Flexible Devices.

Optically clear adhesive (OCA) has been widely used in flexible devices, where wavy stripes that cause troublesome long-term reliability problems often occur. The complex mechanical behavior of OCA should be studied, as it is related to the aforementioned problems. Therefore, it is necessary to establish reasonable mechanical constitutive models for deformation and stress control. In this work, hyperelastic and viscoelastic mechanical tests were carried out systematically and relative constitutive models of OCA material were established. We found that temperature has a great influence on OCA's mechanical properties. The stress and modulus both decreased rapidly as the temperature increased. In the static viscoelasticity test, the initial stress at 85 °C was only 12.6 kPa, 57.4% lower than the initial stress at 30 °C. However, in the dynamic test, the storage modulus monotonically decreased from 1666.3 MPa to 0.6628 MPa as the temperature rose, and the decline rate reached the maximum near the glass transition temperature (Tg = 0 °C). The test data and constitutive models can be used as design references in the manufacturing process, as well as for product reliability evaluation.

Carbon dioxide capture coupled with magnesium utilization from seawater by bipolar membrane electrodialysis.

Carbon dioxide (CO2) capture coupled with further mineralization in high value-added form is a great challenge for carbon capture utilization and storage (CCUS) processes. In this work, a bipolar membrane electrodialysis (BMED) technique integrated with crystallization chamber was proposed to utilize CO2-derived carbonates and the residual magnesium resource from seawater to produce functional nesquehonite. To ensure the stable CO2 storage and magnesium extraction by BMED process, the metastable zone during nesquehonite crystallizing was first measured to modulate crystallization rate, obtain high-quality crystal products and inhibit membrane fouling states. Subsequently, the effects of current density, temperature, and CO2 flow rate during the whole BMED-crystallization process were further investigated. The increase in current density and temperature was conducive for the extraction of magnesium while the enlarged gas flow rate induced higher absorption of CO2. Under the current density at 22 A/m2, CO2 flow rate at 50 mL/min and temperature at 30 °C, the optimal carbon absorption ratio and the magnesium extraction ratio reached 50.85% and 56.71%, respectively. Under this condition, the explosion nucleation of the nesquehonite was effectively avoided to inhibit membrane fouling and the generation of magnesium hydroxide was depressed to obtain the target product nesquehonite. This study on simultaneous carbon capture and magnesium utilization provides theoretical guidance for the industrial green storage of CO2 and development of valuable magnesium products.

De Novo Fabrication of Large-Area and Self-Standing Covalent Organic Framework Films for Efficient Separation.

Covalent organic frameworks (COFs) have aroused extensive attention from various fields owing to their numerous advantages, including permanent porosity, high crystallinity, strong robustness, and well-ordered channels. However, the poor processability of the crystallite powder has greatly impeded their further utilization in many advanced devices and frontier areas. In this work, we fabricate a series of COF films using an interfacial polymerization strategy at a liquid-liquid interface under ambient conditions. The as-synthesized freestanding films are continuous, flexible, and defect-free and have large areas of up to 4 × 6 cm2. In addition, the pore sizes of these COF films can be well controlled based on the principle of reticular chemistry. These films exhibit high chemical stability even in acidic and basic aqueous solutions. More significantly, the highly robust COF films can serve as a nanofiltration membrane for efficient separation of pollutant molecules with different dimensions. These films show high selectivity for the separation of mixed molecule feed and excellent recyclability without a significant loss in the rejection rate.