Diffusion-regulated interfacial copolymerization of poly(ester amide) thin film composite membranes using trihydroxybenzene monomers

Thin-film composite (TFC) membranes fabricated by interfacial polymerization (IPz) underpin modern separations, yet their chemistry remains dominated by polyamide systems. Here, we introduce a versatile thiol-ene interfacial photo-cross-linking strategy as an expansion of IPz to produce ultrathin films as membrane selective layers. In particular, vinyl-rich polymers or vinyl-functionalized nanoparticles were cross-linked with dithiols at a water/oil interface under UV irradiation in ambient air. We first show that this process can be effective for three vinyl-containing systems─poly(dimethylsiloxane) (PDMS) as poly(dimethyl-co-vinylmethyl siloxane), poly(1,2-butadiene) (PB), and vinyl-functionalized silica nanoparticles (SiNPs)─with the three systems readily forming nonporous (PDMS, PB) and porous (SiNPs) thin films. We further explored the two polymeric systems, including the impact of reaction time, dithiol type, and reactant ratio on film thickness and properties. PDMS-derived layers exhibited dense morphologies and near-zero water permeability, but with relatively thick films of 1-7 μm. Under similar reaction conditions, PB-derived films had much lower thicknesses of 60-200 nm and had minimal defects, as demonstrated by phenol/NaCl selectivities as high as 2000 under optimized thiol:ene ratios and reaction times. Infrared spectroscopy and electron microscopy supported efficient thiol-ene addition and continuous coverage of the porous support. We attribute the greater thicknesses in PDMS to greater expected permeabilities of reactants through the nascent film. This work extends thiol-ene IPz as a robust, oxygen-tolerant, and scalable platform for fabricating ultrathin selective layers, and can serve as a foundation for future work to form chemically modifiable nonporous and porous nanofilms.

Asymmetric ion-selective membranes show promise for efficient osmotic energy harvesting. Most current asymmetric membranes adopt a bipolar structure to mitigate concentration polarization. However, this approach usually increases transport resistance and compromises ion selectivity. To address these, we rationally designed a dual polyamide thin-film composite (dPA TFC) membrane via sequential interfacial polymerization (IP). The membrane is composed of two distinct polyamide (PA) layers in situ formed on a macroporous substrate. Through a surfactant-assisted IP process, an ultrathin inner PA layer with a uniform and negatively charged 3D pore structure was obtained, delivering both high ion selectivity and permeability. Subsequently, a loose outer PA layer featuring a mosaic charge architecture was constructed using protonated porphyrin as a building block. This layer promotes significant unidirectional ion transport and effectively suppresses concentration polarization, while maintaining a high cation selectivity of 0.962. Additionally, the membrane exhibits photo-responsive behavior, enabling photo-enhanced osmotic energy conversion and antibacterial activity. As a result, the dPA TFC membrane achieves a high osmotic power density of 13.2W m-2 under light irradiation. This work provides a design paradigm that overcomes the conventional permeability-selectivity trade-off while simultaneously balancing ion concentration polarization suppression with high selectivity, thereby advancing the development of osmotic energy conversion systems.

Forward osmosis (FO) technology for desalination and wastewater treatment has been widely researched because of its significant advantages over traditional pressure-driven membrane processes. However, this process encounters several challenges like low water flux, high reverse solute flux, and inadequate fouling resistance, which necessitate careful consideration in membrane design. This research focuses on improving the desalination, antifouling, and heavy metal rejection efficiency of thin-film nanocomposite (TFN) FO membranes by integrating a CuAl LDH-zeolite X (LDH-Z) into the polyamide active layer. To synergistically exploit the structural characteristics of both LDH and zeolite, the LDH-Z composite was synthesized via a simple in situ coprecipitation method, enabling LDH growth on the external surface and within the pores of zeolite. The intrapore growth of LDH modulated Z internal pore size and enhanced its ion rejection abilities, while the formation of textural mesoporous nanochannels facilitated water transport. FO performance evaluations revealed that the optimized TFN-LZ2 membrane achieved a 64.3% increase in water flux relative to the unmodified TFC membrane. Meanwhile, it maintains reverse solute flux comparable to that of the TFC membrane while exhibiting a 1.35-fold higher selectivity. Moreover, antifouling tests show that water flux decline decreased from 41.9% (TFC) to 26.3% for the optimized membrane due to enhanced surface hydrophilicity and smoothness imparted by LDH-Z. The TFN-LZ2 membrane also performs more effectively at rejecting Cd2+ and Cu2+ heavy metal ions (>97%). These results underscore the capability of LDH-Z-modified membranes to improve FO performance, presenting a promising avenue for FO membrane modification using 2D/3D structured materials.

Butanol vapour sensing performance of spray deposited ZnO/CeO2 composite thin film

This study focuses on developing the amine-functionalized zeolitic imidazole framework-8 (NH2-ZIF-8) encapsulated onto sulfone-functionalized graphene oxide (SGO) to enhance the properties of the PA-TFC membrane for textile wastewater treatment. Zeolitic imidazole framework-8 (ZIF-8) and graphene oxide (GO) were both functionalized with 3-amino-1,2,4-triazole (Atz) and sulfanilic acid, respectively, to achieve NH2-ZIF-8@SGO. The composition of NH2-ZIF-8 was varied on SGO via the in-situ growth method to acquire the optimum formulation of the NH2-ZIF-8@SGO composite. The optimum 0.5% formulation of NH2-ZIF-8@SGO was embedded into the PA layer to enhance membrane performance. The results confirmed that NH2-ZIF-8@SGO-modified TFC membranes exhibited improved water flux and fouling resistance with ∼90% water flux recovery. In addition, the TFC membranes rejected above 99% of textile wastewater primarily through size exclusion and the Donnan exclusion mechanism. These results show that NH2-ZIF-8@SGO increases the hydrophilicity of the PA-TFC membrane and contributes to its high rejection efficiency, improved antifouling performance, and prolonged operational lifespan.

Interpretable artificial intelligence enabled thin-film composite reverse osmosis membranes for desalination

Polymer nanofilm with amphiphilic network for fast and precise molecular separation.

pH-mediated polyethyleneimine-based thin-film composite membranes for high-performance pervaporation desalination

Precise and speedy determination of dopamine (DA) levels in bio-fluids is crucial since DA is a key neurotransmitter involved in regulating motor control, awareness, and emotional balance, and its abnormal concentration is directly linked to various neurological disorders. Accordingly, electrochemical nonenzymatic biosensors provide a promising platform for DA detection. In this study, a facile and low-cost galvanic deposition technique was employed to fabricate a nanostructured composite thin film of α-Fe2O3/α-FeO(OH), which enabled enhanced electrocatalytic activity and direct electron transfer at the electrode interface for DA detection. The sensor exhibited very low detection limit of 0.024µM and excellent sensitivity of 20.6µA cm-2µM-1 toward DA oxidation to dopamine-o-quinone at an optimized operational potential of 0.75V versus Ag/AgCl. With stable redox couple of Fe3+/Fe2+ in Fe2O3 and access to abundant electro-active sites provided by α-FeO(OH) charge transfer kinetics is smoothly facilitated. The OH radical assisted mechanistic confirmation of the oxidation pathway was validated using spectroscopic probes, ensuring reliability of the catalytic process. This technique demonstrated high selectivity against common interfering biomolecules such as ascorbic acid, uric acid etc., along with long-term stability, reproducibility, and repeatability, making it suitable for real-time DA monitoring in complex biological matrices such as serum or cerebrospinal fluid.

Impact of Energy Optimization of a PMSM-Driven High-Pressure Pump on Commercial TFC Membrane Performance in Reverse Osmosis Desalination

In-situ growth of layer double hydroxides on TFC membranes to improve forward osmosis performance

Freshwater scarcity driven by population growth and industrial demand has increased reliance on desalination, where reverse osmosis (RO) is widely applied due to its high separation efficiency. Membrane performance is governed by the balance between water permeability and solute rejection, and attempts to improve this relationship have focused on incorporating nanomaterials to modify membrane structure and transport behavior. In this study, a computational investigation was carried out for thin-film composite (TFC) membranes incorporating graphene oxide-poly(amidoamine) (GO-PAMAM) within the polysulfone substrate to examine its influence on transport under RO conditions. A two-dimensional model was implemented in COMSOL Multiphysics by coupling the Laminar Flow and Transport of Diluted Species interfaces, while permeation across the membrane was described using a solution-diffusion framework parameterized by experimentally determined salt permeability coefficient. Variation in GO-PAMAM loading (0-0.10 wt%) was introduced through intrinsic permeability parameters, enabling direct comparison with experimental data. The simulations reproduced the observed trends, with the membrane containing 0.06 wt% GO-PAMAM showing higher salt rejection, increasing from 78.16% to 90.08% relative to the pristine membrane. The model predicted lower permeate-side solute concentration and a decrease in salt rejection along the membrane length. Model predictions agreed with experiments, with mean relative errors of 1.23% for salt rejection and 7.41% for water flux, demonstrating the ability of the model to capture transport behavior in GO-PAMAM-modified TFC membranes.

The development of flexible, high-performance thermoelectric materials is necessary due to the growing demand for sustainable energy conversion from waste heat sources. In this work, we present higher manganese silicide/polyaniline (HMS/PANI) composite thin films that exhibit a hierarchical interface design, which partially decouples the typically interrelated thermoelectric parameters for waste heat recovery from working 3D printers. Structural characterization studies - XRD and SEM - confirm the well-dispersed HMS network with good interfacial quality. Through systematic composition optimization, we achieved enhanced electrical conductivity, 438 S m-1, and a simultaneous increase in the Seebeck coefficient of 72 μV K-1 at 80% HMS content. This enhancement results from hierarchical composite engineering, achieved by percolation-driven charge transfer at HMS/PANI interfaces and energy filtering effects, which also increase carrier concentration. The optimized composition exhibits an enhanced power factor of 2.3 μW (mK2)-1. Phonon engineering suppresses the lattice thermal conductivity relative to pure PANI, thereby maximizing the thermoelectric performance of composites. I-V characterization confirms the ohmic transport behaviour across all compositions. Device output characterization demonstrates a maximum power generation of 0.33 nW at ΔT = 70 K. Real-time application demonstration on an operating 3D printer reveals stable performance by generating 6-8 mV output, validating its functionality for autonomous IoT energy harvesting systems. This work establishes HMS/PANI composites as a flexible thermoelectric material where sophisticated composite design transcends individual phase limitations, paving the way for practical thermoelectric energy harvesting from diverse waste heat sources.

Forward osmosis (FO) membranes have garnered widespread research interest in water treatment, yet their permeability-selectivity trade-off, internal concentration polarization, and membrane fouling remain critical challenges. Herein, a chitooligosaccharide/polydopamine (COS/PDA) co-deposition strategy was proposed to modify polyethersulfone (PES) substrates for constructing high-performance thin-film composite (TFC) FO membranes. COS suppressed excessive PDA aggregation, reduced substrate roughness, and improved substrate hydrophilicity. This substrate modification regulated interfacial polymerization by increasing the adsorption capacity for m-phenylenediamine (MPD) while slowing its diffusion rate, thereby forming thinner, smoother, and more densely crosslinked polyamide (PA) layers. The optimized C4P1-TFC membrane delivered water fluxes of 42.2 and 23.5 L m-2 h-1 in pressure-retarded osmosis (PRO) and FO modes, respectively, representing 43.1% and 40.2% improvements over the pristine membrane. Its specific salt flux decreased to 0.07 and 0.15 g L-1 in the two modes, respectively, suggesting enhanced selectivity. Meanwhile, the C4P1-TFC membrane showed antibacterial rates of 85.7% against Escherichia coli and 86.9% against Staphylococcus aureus, together with improved antifouling performance against bovine serum albumin and lysozyme. This work presents a simple and effective co-deposition approach for simultaneously improving the separation, antibacterial, and antifouling performance of TFC FO membranes, showing promising potential for practical applications.

Thin-film composite (TFC) polyamide (PA) nanofiltration membranes are the state of the art for water purification and reclamation, although a selectivity–permeability trade-off often restricts their development. To mitigate this problem, in this work, a novel three-layer structured nanofiltration (NF) membrane was fabricated consisting of a negatively charged poly (sodium 4-styrenesulfonate) (PSS) interlayer, a high-performance polyethyleneimine (PEI)-based PA separation layer and a PEI-grafted top layer. The PSS interlayer aimed to regulate interfacial polymerization (IP) of PEI with trimesoyl chloride (TMC) and enhance water transport, while PEI-grafting ensured high salt rejections. The relevant characterizations indicated that PEI-grafting endowed the resulting membrane (I-TFC-g) with a positive surface charge and increased the crosslinking degree to achieve much higher rejections for Mg+2 ions through the synergistic effect of Donnan and size-exclusion mechanisms, while the incorporation of the PSS interlayer resulted in an increased pure-water permeability (PWP) value of 7 L m−2 h−1 bar−1 (a value 2.8 times higher compared to the membrane TFC-g without a PSS interlayer). In specific, the I-TFC-g membrane displayed the highest salt rejections of 91% for MgCl2, 92% for MgSO4, 73% for Na2SO4 and 58% for NaCl and a good long-term stability. Overall, this work presents a simple strategy to improve NF performance by simultaneous enhancement of water permeability and salt selectivity.

While aluminum (Al) continues to be a cornerstone for microelectronic interconnect technologies, its chronic tendency toward hillock growth and thermal instability necessitates a transition toward high-performance nanostructured material architectures. This research tackles these reliability bottlenecks by achieving a molecular-level integration of graphene nanoplatelets (GNPs) within Al matrices, a strategy designed to fortify structural resilience. Adopting a green chemistry approach, we synthesized Al-GNP (0.25 vol.%) composite thin films through Pulsed Laser Deposition (PLD) using precursors derived from recycled aluminum. A major obstacle—the formation of the deleterious Al4C3 intermetallic phase—was effectively suppressed by ensuring a homogeneous supramolecular dispersion via a specialized dual protocol (ultrasonication and magnetic stirring) during the powder metallurgy stage. Comprehensive physicochemical characterization, utilizing HR-TEM and XRD, verified the structural integrity of the multilayer GNPs (d-spacing = 4.6 Å). Furthermore, surface metrology analysis uncovered a radical shift in growth kinetics: whereas pure Al grew via a “spiky” Volmer-Weber mechanism (Sku = 31.17), the carbon-based inclusion stabilized the film evolution, tempering the kurtosis to Sku = 7.74. Analytical cross-sectional EDS confirmed both stoichiometric fidelity and the achievement of void-free Si/Pt/Al-GNP interfaces. These outcomes prove that a precise nanoscale tailoring of surface morphology via carbonaceous reinforcements significantly bolsters microstructural stamina. Consequently, these PLD-deposited composites emerge as sustainable, cutting-edge candidates for the next generation of microelectronic packaging and interfacial chemistry applications.

Water stress is intensifying worldwide, increasing the need for efficient desalination and water purification technologies. Although commercial nanofiltration membranes such as NF90 exhibit high separation performance, their transport properties remain governed by permeability–selectivity trade-offs, and their surface characteristics offer limited tunability for application-specific requirements. Here, a commercial NF90 polyamide thin-film composite nanofiltration membrane was surface modified by depositing ultrathin ZnO coatings via RF sputtering (30–120 s) and evaluated in terms of surface properties, water permeate flux, and NaCl rejection. X-ray diffraction confirmed the formation of crystalline Wurtzite ZnO with preferential (002) orientation. ZnO deposition markedly increased surface hydrophobicity, raising the water contact angle from 52.5 ± 2.0° for the unmodified membrane to 140.4 ± 3.9° after 120 s of deposition. Hydraulic performance decreased after modification, with water permeate flux reduced by approximately 47–50% relative to pristine NF90. In contrast, NaCl rejection increased with ZnO deposition time, particularly at lower operating pressures, and tended to plateau at higher pressures. The Spiegler–Kedem model accurately described experimental rejection-flux behavior. Overall, RF sputtering of ZnO is a feasible post-fabrication route to tune NF membrane selectivity, while introducing a clear trade-off with permeate flux.

The growing demand for sustainable energy sources and the rapid growth of wearable electronics have driven the need for efficient, flexible, and self-powered energy-harvesting systems. In this report, we demonstrated the fabrication of flexible, low-cost, portable, and self-powered triboelectric nanogenerators (TENGs) using vanadium pentoxide (V2O5 (VO)) nanoparticle (NPs)-loaded chitosan (CS) composite films to be used for energy harvesting, storage, and biomechanical and sensing applications. The VO phase's purity and surface morphology were confirmed by X-ray diffraction (XRD) and field-emission scanning electron microscope (FE-SEM) analysis. The VO/CS composite thin films were prepared by systematically varying the VO weight concentration (0, 0.5, 1, 2, and 3 wt %) within the CS matrix. The TENG device was fabricated using different wt % VO/CS composite films and ecoflex as tribo positive and tribo negative layers, respectively, and aluminum was used as a conductive electrode to both the tribo films. A contact-separation mode was used to evaluate the electrical output of the TENG device. The optimized 2 wt % VO/CS composite film-based TENG generated the maximum electrical output voltage, current, charge density, and power density of ∼205 V, 6.2 μA, 96.5 μC/m2, and 3.9 W/m2, respectively. The fabricated TENG device demonstrated robust performance and sustained stable electrical output over a long period. In addition, the generated electrical energy was efficiently stored in capacitors and utilized to power up low-power electronic devices. Furthermore, an optimized TENG device was placed at various locations on the human body to evaluate electrical output from biomechanical energy. Thereafter, the TENG-powered self-illuminating device was demonstrated as a smart safety walker wearable bracelet alert system.

High-performance thin-film composite mixed-matrix membranes enabled by amphiphilic block copolymer and green-synthesized polyimide COF: Integrating experimental and simulation insights