Symmetric Membranes Research Articles

Building Asymmetric Lipid Bilayers for Molecular Dynamics Simulations: What Methods Exist and How to Choose One?

The compositional asymmetry of biological membranes has attracted significant attention over the last decade. Harboring more differences from symmetric membranes than previously appreciated, asymmetric bilayers have proven quite challenging to study with familiar concepts and techniques, leaving many unanswered questions about the reach of the asymmetry effects. One particular area of active research is the computational investigation of composition- and number-asymmetric lipid bilayers with molecular dynamics (MD) simulations. Offering a high level of detail into the organization and properties of the simulated systems, MD has emerged as an indispensable tool in the study of membrane asymmetry. However, the realization that results depend heavily on the protocol used for constructing the asymmetric bilayer models has sparked an ongoing debate about how to choose the most appropriate approach. Here we discuss the underlying source of the discrepant results and review the existing methods for creating asymmetric bilayers for MD simulations. Considering the available data, we argue that each method is well suited for specific applications and hence there is no single best approach. Instead, the choice of a construction protocol-and consequently, its perceived accuracy-must be based primarily on the scientific question that the simulations are designed to address.

Distributing aminophospholipids asymmetrically across leaflets causes anomalous membrane stiffening

We studied the mechanical leaflet coupling of prototypic mammalian plasma membranes using neutron spin-echo spectroscopy. In particular, we examined a series of asymmetric phospholipid vesicles with phosphatidylcholine and sphingomyelin enriched in the outer leaflet and inner leaflets composed of phosphatidylethanolamine/phosphatidylserine mixtures. The bending rigidities of most asymmetric membranes were anomalously high, exceeding even those of symmetric membranes formed from their cognate leaflets. Only asymmetric vesicles with outer leaflets enriched in sphingolipid displayed bending rigidities in conformity with these symmetric controls. We performed complementary small-angle neutron and x-ray experiments on the same vesicles to examine possible links to structural coupling mechanisms, which would show up in corresponding changes in membrane thickness. In addition, we estimated differential stress between leaflets originating either from a mismatch of their lateral areas or spontaneous curvatures. However, no correlation with asymmetry-induced membrane stiffening was observed. To reconcile our findings, we speculate that an asymmetric distribution of charged or H-bond forming lipids may induce an intraleaflet coupling, which increases the weight of hard undulatory modes of membrane fluctuations and hence the overall membrane stiffness.

Symmetric structured porous supported mixed conductor ceramic membrane boosting oxygen permeation flux

An effective symmetric structured dual phase mixed conducting oxygen separation membrane made of 60 wt% Ce0.9Gd0.1O2-δ − 40 wt% Ba0.5Sr0.5Co0.8Fe0.2O3-δ (60CGO-40BSCF) were prepared by the aqueous tape casting. The symmetric ceramic membranes consisted of a dense thin layer with a thickness of around 50 µm in the middle, and two porous substrates (around 290 µm thick) located on the two sides of the middle thin dense layer. In this case, both the bulk diffusion of oxygen ion and surface gas exchange are simultaneously optimized to enlarge the oxygen permeation flux. In addition, a symmetric structure favors to stabilize the ceramic membrane. Compared with monotonous dense membrane, the porous supported symmetric membrane delivered higher permeation fluxes, e.g., 3.78 ml cm−2 min−1 at 975 °C under an air/He gradient, while an oxygen permeation flux of 1.42 ml cm−2 min−1 was obtained for the monotonous dense membrane. As increasing the O2 partial pressure in the feed side to 0.8 atm, an oxygen permeation flux of 8.67 ml cm−2 min−1 was obtained. The current study implies that the porous supported symmetric membrane structure is an efficient strategy to enhance the oxygen permeation flux.

Modification of a PES microfiltration membrane to enhance sterile filtration by inhibiting protein adsorption

Microfiltration membranes are increasingly used in sterilization processes in the pharmaceutical industry. However, in the pharmaceutical industry, product loss caused by the adsorption of high value-added proteins to membranes during the sterilization process is a critical problem. Hence, it is necessary to reduce protein adsorption and fouling through the hydrophilic modification of the entire membrane, not just the surface. We developed a method for fabricating a porous poly(ethersulfone) (PES) microfiltration membrane using vapor-induced phase separation (VIPS) and then conducting hydrophilic modification of the membrane. Two types of symmetric membranes with 0.2 μm pores were prepared using two different additives, one of which was an amphiphilic copolymer (Pluronic® PE6400) that is known to increase the hydrophilicity of PES membranes. Both membranes had high water permeability and suitable mechanical strength. However, protein filtration testing, including an adsorption study, revealed that the hydrophilicity imparted by Pluronic was not sufficient to effectively inhibit protein adhesion. In contrast, the modification via the atom transfer radical polymerization of a hydrophilic oligomer (poly(ethyleneglycol) methacrylate) significantly increased the hydrophilicity of the entire membrane while reducing the surface roughness. These properties reduced protein adsorption and membrane fouling, to the benefit of sterile filtration and protein filtration processes.

Enhancing carbon capture efficiency of zeolite-embedded polyether sulfone mixed-matrix membranes via annealing process

Current work was motivated by rapid advancement in membrane technology for application of gas separation, that resulted in the formation of mixed-matrix membranes (MMMs) with higher selectivity and permeability. MMMs are one way to get above the Robeson upper bound of selectivity against permeability for gaseous separation while retaining the advantages of solution processing. Numerous inorganic materials like zeolites, carbon nanotubes, or metal-organic frameworks can behave as molecular sieves, but they are fragile and difficult to fabricate as standalone membranes. This problem might be solved by embedding them into a more durable polymeric membrane matrix. In this work, symmetric mixed-matrix membranes fabricated through solution casting technique were employed with zeolite A-3 dispersed in a polyether sulfone (PES) matrix. Impacts of zeolite loading and annealing temperatures on thermal stability, morphology and carbon capture performance of prepared membranes were systematically investigated. Carbon capture proficiency of fabricated membranes was assessed in terms of CO2 permeability and CO2/N2 selectivity. In contrast to pristine PES membrane, incorporation of optimal 30 wt% zeolite into polymer matrix enhanced CO2 permeability from 81 to 128 Barrer and CO2/N2 selectivity from 9 to 22. Annealing the composite membranes at 155 °C led to further enhance CO2 permeability at the expense of reduced CO2/N2 selectivity: CO2 permeability of pristine PES membrane enhanced from 81 to 126 Barrer by decreasing its CO2/N2 selectivity from 9 to 6; CO2 permeability improved from 128 to 144 Barrer while CO2/N2 selectivity declined from 22 to 18 for composite membrane imbedded with 30 wt% optimum zeolite loading.

Multi-functional Ag@NH2-UiO-66/PAES-COOH self-supporting symmetric hybrid membrane for forward osmosis separation

Currently, internal concentration polarization (ICP) and surface contamination of conventional thin-film composite membranes have become the main factors hindering the development and application of forward osmosis technology. Herein, the optimized hydrophilic Ag@NH2-UiO-66 with water molecule specific channels and antibacterial property was integrated into the molecular structure of carboxyl-containing poly (aryl ether sulfone) (PAES-COOH) matrix with excellent mechanical properties through precise molecular design, which was further combined with the structure design of support layer free to fabricate a series of Ag@NH2-UiO-66/PAES-COOH self-supporting symmetric hybrid forward osmosis membrane system without ICP. The strong chemical bonding between Ag@NH2-UiO-66 filler and PAES-COOH matrix enabled the two parts to form good interfacial compatibility, which promoted the full play of multiple functionalities of Ag@NH2-UiO-66. In consequence, the Ag@NH2-UiO-66/PAES-COOH self-supporting symmetric hybrid forward osmosis membranes exhibited excellent water permeability (13.78 L m−2 h−1 of the optimal sample) and water-salt selectivity (1724.70 L mol−1 of the optimal sample) effective antibacterial capability, as well as enhanced organic pollution resistance ability. This research provides an effective strategy for the realization of self-supporting symmetric forward osmosis membrane with multiple functionalities, which can be extended to other membrane systems to promote the development of future osmosis technology.

Theoretical NMR and IR spectroscopic analyses of the preferred conformers of the neurotransmitter anandamide

AbstractAnandamide, an endogenous fatty acid, displays a wide conformational space due to the nature of its chemical structure, particularly its polyunsaturated aliphatic chain component (omega‐6 fatty acid). Six main minima are considered after a conformational search based on the MM+ method, namely, extended shape, U‐shape, and hairpin shape with either an open or a closed conformation of the ethanolamide (EA) ring. For these six conformers, DFT calculations were performed to theoretically characterize their structural stability, NMR and IR spectroscopic, and electronic properties using the BP86/cc‐pVTZ level of theory with the solute‐implicit solvent model PCM. DLPNO‐CCSD(T) level of theory was used for comparison with DFT results. Our results indicate that the conformers with closed EA ring are more stable than their corresponding open ring counterparts. With the NMR and IR spectroscopies was characterized the formation of the intramolecular hydrogen bond in the closed conformers of the EA ring. The electronic properties investigated include the calculation of the frontier molecular orbitals (FMO), the molecular electrostatic potential (MEP), and the natural bond orbitals (NBO). Additionally, the multiscale ONIOM QM1/QM2 model was used to simulate a solute‐explicit solvent system and molecular dynamics simulations were used to simulate the anandamide systems embedded in a hydrated symmetric POPC membrane and in aqueous solution. The results suggest that alkyl‐middle and EA groups in anandamide may play an important role in the ligand‐receptor interaction.

Phosphatidylinositol phase behavior in symmetric and asymmetric model membranes.

Phosphatidylinositol (PI) is a precursor to phosphoinositides (PIPs) which are important cellular signaling molecules. While the phase behavior of PI in simple model membranes has been investigated, little is known about its phase behavior in the presence of PIPs. Furthermore, the effect of divalent cations on PI/PIP interaction has not been detailed. Determining PI/PIP phase behavior is of physiological relevance because it potentially affects the lateral distribution of PIPs in cellular membranes and hence the spatiotemporal control of protein function. For diplamitoylphosphatidylinositol (DPPI) we find in pH 7.2 buffer a phase transition temperature of 43.6°C, while in the presence of Ca2+ and Mg2+ the phase transition temperature shifts to 55.8°C and 51.6°C, respectively. In addition, we investigate divalent cation dependent PI/PI(4,5)P2 phase behavior. To study PI phase behavior in asymmetric lipid bilayers, we fabricate asymmetric giant unilamellar vesicles (aGUVs) using the hemifusion method. We describe the conditions to obtain aGUVS with PI in the outer leaflet and characterize their domain morphology.

Determining the Bending Rigidity of Free-Standing Planar Phospholipid Bilayers

We describe a method to determine membrane bending rigidity from capacitance measurements on large area, free-standing, planar, biomembranes. The bending rigidity of lipid membranes is an important biological mechanical property that is commonly optically measured in vesicles, but difficult to quantify in a planar, unsupported system. To accomplish this, we simultaneously image and apply an electric potential to free-standing, millimeter area, planar lipid bilayers composed of DOPC and DOPG phospholipids to measure the membrane Young's (elasticity) modulus. The bilayer is then modeled as two adjacent thin elastic films to calculate bending rigidity from the electromechanical response of the membrane to the applied field. Using DOPC, we show that bending rigidities determined by this approach are in good agreement with the existing work using neutron spin echo on vesicles, atomic force spectroscopy on supported lipid bilayers, and micropipette aspiration of giant unilamellar vesicles. We study the effect of asymmetric calcium concentration on symmetric DOPC and DOPG membranes and quantify the resulting changes in bending rigidity. This platform offers the ability to create planar bilayers of controlled lipid composition and aqueous ionic environment, with the ability to asymmetrically alter both. We aim to leverage this high degree of compositional and environmental control, along with the capacity to measure physical properties, in the study of various biological processes in the future.

The pH as a tool to tailor the performance of symmetric and asymmetric layer-by-layer nanofiltration membranes

Layer-by-layer assembly of polyelectrolyte layers is a versatile method to produce nanofiltration membranes. The membrane formation and subsequently performance is easily tailored with pH as it varies the polyelectrolyte charge density. Here, membranes are fabricated at different pH (4,8, and 9) with branched polyethyleneimine (PEI)/poly(sodium-4-styrenesulfonate) (PSS) layers (symmetric membranes) or a combination of poly(diallyldimethylammonium chloride) (PDADMAC)/PSS base layers terminated with PEI/PSS layers (asymmetric membranes).Overall, increasing the pH lowers the PEI charge density, which increases PEI adsorption, as measured by optical reflectometry and positive zeta potential. For symmetric systems, decreasing the charge density decreases the salt retention, because fewer intrinsic linkages are formed. Contrarily, asymmetric membranes, independent of charge density, show retentions >90% for MgSO4 and Na2SO4.Additionally, the benefit of asymmetric membrane formation is proven by comparing the best membrane performances. Asymmetric membranes prepared at pH = 4 form an open base layer and defect-free dense selective layer, resulting in much higher permeabilities compared to symmetric membranes (∼13 and ∼9 L/(m2hbar)), and significantly improving MgSO4 and Na2SO4 retentions (>95% compared to >90%).By combining two well-known polycations and tailoring the pH, versatile membranes are produced, without the need for synthesis or modification steps while obtaining improved water fluxes and salt retentions.

Cellular function of (a)symmetric biological membranes.

In mammalian cells, phospholipids are asymmetrically distributed between the outer and inner leaflets of the plasma membrane. The maintenance of asymmetric phospholipid distribution has been demonstrated to be required for a wide range of cellular functions including cell division, cell migration, and signal transduction. However, we recently reported that asymmetric phospholipid distribution is disrupted in Drosophila cell membranes, and this unique phospholipid distribution leads to the formation of highly deformable cell membranes. In addition, it has become clear that asymmetry in the trans-bilayer distribution of phospholipids is disturbed even in living mammalian cells under certain circumstances. In this article, we introduce our recent studies while focusing on the trans-bilayer distribution of phospholipids, and discuss the cellular functions of (a)symmetric biological membranes.

Positive space acquiring asymmetric membranes for guiding alveolar bone regeneration under infectious conditions

To obtain multifunctional materials suitable for guiding alveolar bone regeneration under infectious conditions, we prepared asymmetric membranes comprising space acquiring layer that involves fibroblast inhibitor poly(p-dioxanone-co-L-phenylalanine) (PDPA), an isolating dense layer that forms barrier between two layers and an osteogenesis inducing electrospinning layer which involves hydroxyapatite or hydroxyapatite & minocycline. Then the composition, crystallization, morphology, and hydrophilicity of asymmetric membranes were analyzed. Minocycline incorporated membranes controlled the expansion of Porphyromonas gingivalis (P. gingivalis) in vitro. Hydroxyapatite-incorporated asymmetric membranes promoted the expression of osteogenesis related genes RUNX2, OPN, ALP of MC3T3-E1 cells in vitro. The mineralization of MC3T3-E1 cells cultured with hydroxyapatite-incorporated asymmetric membranes were also promoted in vitro. Asymmetric membranes especially hydroxyapatite-incorporated ones guided the regeneration of the mandibular bone defect in vivo. Bone regeneration guided under infectious conditions was evaluated in a P. gingivalis infected alveolar bone defect model. Specifically, space acquiring layer containing asymmetric membranes effectively controlled connective tissue hyperplasia at defect sites. The excellent guided bone regeneration achieved by applying a single space acquiring layer membrane further indicates the importance of acquiring space actively to induce bone regeneration. Hydroxyapatite-minocycline incorporated symmetric membranes could simultaneously suppress alveolar bone reabsorption caused by infection and guide regeneration of defects. Therefore, the hydroxyapatite-minocycline incorporated asymmetric membrane may be more suitable to be applied in guiding regeneration of bone defects under complex infectious conditions.

A Green Stable Antifouling PEGylated PVDF Membrane Prepared by Vapor-Induced Phase Separation.

While green solvents are being implemented in the fabrication of polyvinylidene fluoride (PVDF) membranes, most are not compatible with the vapor-induced phase separation (VIPS) process for which relatively low dissolution temperatures are required. Additionally, preparing antifouling green membranes in one step by blending the polymer with an antifouling material before inducing phase separation remains extremely challenging due to the solubility issues. Here, the green solvent triethyl phosphate (TEP) was used to solubilize both PVDF and a copolymer (synthesized from styrene monomer and poly(ethylene glycol) methyl ether methacrylate). VIPS was then used, yielding symmetric bi-continuous microfiltration membranes. For a 2 wt% copolymer content in the casting solution, the corresponding membrane P2 showed a homogeneous and dense surface distribution of the copolymer, resulting in a high hydration capacity (>900 mg/cm3) and effective resistance to biofouling during the adsorption tests using bovine serum albumin, Escherichia coli or whole blood, with a measured fouling reduction of 80%, 89% and 90%, respectively. Cyclic filtration tests using bacteria highlighted the competitive antifouling properties of the membranes with a flux recovery ratio after two water/bacterial solution cycles higher than 70%, a reversible flux decline ratio of about 62% and an irreversible flux decline ratio of 28%. Finally, these green antifouling membranes were shown to be stable despite several weeks of immersion in water.

Esterification and transesterification of palm fatty acid distillate in chitosan membrane reactor

Biodiesel from palm fatty acid distillate (PFAD) with FFAs of 87.1 ± 1.3 wt% was studied in a 2-litres chitosan membrane reactor. The reactor used in this study comprised of three parts; i.e., upstream side for reaction, membrane cell and downstream side connecting with a vacuum pump. The feed was operated under esterification reaction followed by transesterification reaction without intermediate washing. Flat sheet symmetric dense uncrosslinked chitosan membrane was used preferably in the laboratory 2-litres reactor. Operating the reactor under the pervaporation process, the optimum esterification condition was at 1:15 of PFAD to methanol ratio, 2.0 wt% H2SO4 and 20 ml/min methanol feed rate for 120 min. The FFA and methyl ester contents in the esterification product were 1.09 ± 0.03 and 85.9 ± 0.1 wt%, respectively. On the transesterification condition at 1:6 of PFAD to methanol ratio, 1.0 wt% NaOH and 20 ml/min methanol feed rate for 60 min, the methyl ester was increased to 97.9 ± 0.0 wt%. On performance and potential application, an 8-litres reactor installing a set of membrane modules was studied. Several membrane modules with flat sheet reinforced crosslinked composite chitosan membranes were installed in the pilot 8-litres reactor. Together with operating the reactor under the pervaporation process, the esterification was operated at 1:15 of PFAD to methanol ratio and 1.5 wt% H2SO4 for 180 min followed by the transesterification reaction at 1:6 of PFAD to methanol ratio and 1.0 wt% NaOH for 60 min without intermediate washing. The methyl ester yield of 96.6 ± 0.02 wt% was obtained.

Bubble dynamics and atomization in evaporating polymeric droplets

We investigate the interaction of an aqueous polymeric droplet with a tuneable continuous laser in an acoustically levitated environment. The effect of laser irradiation intensity and polymeric concentration on various spatio-temporal parameters is unearthed using high-speed shadowgraphy and theoretical scaling analysis. We observe four temporal phases: droplet evaporation, vapour bubble growth followed by membrane inflation, bubble/membrane rupture through hole nucleation and droplet breakup. During the initial droplet evaporation phase, concentration build-up at the droplet surface beyond a critical limit leads to the formation of a skin layer. It is revealed that, at a given location inside the droplet, hot spots occur, and the maximum temperature at the hot spots scales linearly with irradiation intensity until a bubble nucleates. The low-intensity laser interaction leads to symmetric membrane inflation that eventually forms holes at droplet poles and cracks on the shell surface. On the contrary, high intensity causes early bubble nucleation followed by asymmetric membrane inflation that eventually ruptures through multiple hole formation. Furthermore, the growth and rupture of the membrane is followed by a catastrophic breakup of the droplet. Two dominant atomization modes are reported at significantly high irradiation intensities: stable sheet collapse and unstable sheet breakup. The evolution of droplets into a stable/unstable sheet follows universally observed ligament and hole dynamics. A regime map is shown to describe the influence of polymer concentration and irradiation intensity on the strength and mode of droplet atomization.

Effect of membrane mean pore diameter on water and solute flux in forward osmosis processes

Several forward osmosis (FO) experiments were carried out using aqueous solutions of sodium chloride (NaCl) in different concentrations, as draw solution (DS), and freshwater, as feed water (FW). The experiments were conducted at a constant temperature of ~20°C and using a symmetric cellulosic membrane in two grades different in their values of the molecular weight cut-off (MWCO), which is related to the mean pore diameter. This study investigates the effect of the membrane mean pore diameter on water flux and DS solute diffusional flux across the membrane. The value of water flux indicates the performance of the FO process, while solute flux is an important factor that determines its practicality. A proportionality factor is used to specify the relationship between water flux and solute flux for each membrane type and operational conditions. The results of this study show that water flux and solute flux increase as the solute concentration difference across the membrane increases. It is also found that, in the range of the tested membranes, membranes with larger mean pore diameters have lower water flux and higher solute flux.

Control of Enzyme Reaction Initiation inside Giant Unilamellar Vesicles by the Cell-Penetrating Peptide-Mediated Translocation of Cargo Proteins.

Cell-penetrating peptides (CPPs) play important roles in directly delivering biomolecules, such as DNA, proteins, and peptides, into living cells. In artificial lipid membranes, such as planar lipid bilayers, the direct membrane translocation of β-galactosidase via Pep-1 (one of the CPPs) is dependent upon a voltage gradient between the inner and outer leaflets of the lipid membranes. Giant unilamellar vesicles (GUVs) with asymmetric lipid distributions, which are recently generated using microfluidic technologies, can be observed by optical microscopy. Therefore, interactions between CPPs and asymmetric lipid bilayers in different kinds of lipids and the translocation mechanism of proteins via CPPs into GUVs can be investigated at the level of a single asymmetric GUV. This CPP-based system for transporting proteins into GUVs will be applied to control the start of enzyme reactions in GUVs. This study aimed to explore efficient protein translocation into GUVs via CPP and demonstrate that enzymatic reactions start in GUVs using a CPP-mediated direct translocation. The interactions and the enzyme reactions between the CPP (Pep-1 or penetratin)-DNase I complexes and the asymmetric or symmetric GUV membranes containing the negatively or neutrally charged lipids were observed by confocal laser-scanning microscopy. The asymmetric GUVs containing phosphatidylserine (PS) in the inner leaflet showed efficient DNase I translocation into GUVs via penetratin. Finally, the formation of a cross-linked actin network was observed in asymmetric PS GUVs incubated with Pep-1-streptavidin complexes. The CPP-mediated direct translocation can contribute to developing artificial cell models with the capacity to control the initiation of enzymatic reactions.

Efficient and recyclable ultra-thin diameter polyacrylonitrile nanofiber membrane: Selective adsorption of cationic dyes

Membrane separation is a promising technique for the effective removal of dyes from dyeing wastewater resulting from the textile, leather, and paper industries. Herein, we successfully prepared a new symmetrical and self-supporting reconstituted polyacrylonitrile (re-uPAN) membrane by a simple and general method combined island-in-sea bicomponent electrospinning and reconstitution. The simple preparing procedure allows the re-uPAN membranes to retain the chemical structure and dye-absorbing property of the original nanofibers and simultaneously to gain distinct porous and self-supporting features. Such features further endow the potential application of re-uPAN membrane in the effective removal of dyes from wastewater. As a model system, we prepared an optimized re-uPAN membrane with a mass of 12 mg, which showed an average pure water flux of 63.4 L/m2h at 1 bar and a surface porosity of around 30%. The re-uPAN membrane was then used to remove dyes, giving a removal ratio of 100% when the concentration of dye is below 30 mg/L and an absorption capacity of 816.5 mg/m2. The re-uPAN membranes also showed a distinct selectivity of absorbing cationic dyes, which could be potentially used for dye separation. The good mechanical property and self-supporting feature make the re-uPAN membrane be easily recycled. The re-uPAN membrane could well maintain its adsorption capacity even after ten cycles of separation. The generality and simplicity of our re-uPAN membrane-making method pave a new way for preparing membrane, which shows great potentials of being applied in wastewater treatment, nanotechnology, and separation technology.

Cholesterol’s balancing act: Defying the status quo

The structure and organization of biological membranes have fascinated biophysicists and cell biologists for decades. Some key findings that have energized the field include the discovery of domains in lipid mixtures (1) and the subsequent raft hypothesis linking them to cellular phenomena (2), as well as the discovery of compositional asymmetry in cell bilayers (3), which put lipid membranes on the map of energetically regulated physiological players. Almost all current knowledge about lipid and bilayer biophysics is rooted in studies of symmetric model membranes in the form of closed lipid vesicles.

Development of highly permeable self-standing nanocomposite sulfonated poly ether ketone membrane using covalent organic frameworks

This study developed a new symmetric and ultrathin membrane by incorporating Schiff base network-1 (SNW-1), which are covalent organic framework (COF) nanoparticles, as fillers in the sulfonated poly ether ketone (SPEK) matrix to improve forward osmosis (FO) performance. The amine-rich and porous SNW-1 nanoparticles enhanced the surface wettability of the SPEK membranes and offered additional passages for the water molecules' transport, which assisted in the elevation of membrane water flux. The modified membrane loaded with 20 wt% SNW-1 (COF-20) exhibited the best performance with a significantly higher water flux (28.5 L m−2 h−1) and lower specific reverse solute flux (SRSF, 0.05 g L−1) than that of the unmodified SPEK (COF-0) membrane (water flux of 12 L m−2 h−1 and SRSF of 0.16 g L−1) when experimented with deionized water and 1 M Na2SO4 as feed and draw solutions, respectively. The impressive FO performances of nanocomposite SPEK membranes suggest that SNW-1 nanoparticles could be used as fillers for improving the SPEK membrane's performance in the FO application.