Composite Thin Films Research Articles

Turning Microstructure in Block Copolymer Membranes: A Facile Strategy to Improve CO2 Separation Performance.

To mitigate global climate change, the development of membranes with high CO2 permeability and selectivity is urgently needed. Here, a simple and effective non-solvent-induced microstructure rearrangement (MSR) technique is proposed to enhance the gas separation performance of Pebax 2533 membranes. By immersing Pebax 2533 membranes in amino acid salt solutions to induce MSR, the CO2 permeability of the optimized Pebax 2533-GlyK 10wt.% membrane reached 1180 Barrer, a 4.5-fold increase compared to the original membrane, without compromising CO2/N2 selectivity. Moreover, the MSR membrane maintains stable gas separation performance for nearly 500 days, demonstrating excellent long-term stability. Furthermore, applying the MSR technique to thin-film composite (TFC) membranes revealed that both Pebax 2533/polyvinyl chloride (PVC) hollow fiber (HF) TFC membranes and Pebax 2533/polyacrylonitrile (PAN) flat-sheet TFC membranes exhibited significantly enhanced CO2 permeance under the treatment of DI water. Characterization results indicated that the chemical-physical properties of the membranes before and after MSR are nearly unchanged, suggesting that the non-solvent-induced MSR is a promising technique for next-generation membrane development for carbon capture.

Eliminating Nucleation Delay for Atomic Layer-Deposited Low-Defect Dense Multi-Component Thin Films through Preoccupation of Interstitial Sites.

Atomic layer deposition (ALD) is advantageous in the flexible and precise control of the composition and thickness of thin films. However, the nucleation delay during the deposition of multicomponent films leads to unexpected thickness and composition, the mechanism of which is still ambiguous. Herein, we reveal that the surface formed by a certain precursor is self-limiting for itself; there remain interstitial sites for other precursors. This phenomenon results from differences in the steric hindrance and molecular volume between different precursors. To address this issue, we develop a complementary supercycle process consisting of several three-step ALD subcycles that eliminates nucleation delays by preoccupying interstitial sites through a novel three-step subcycle design. Unlike conventional supercycle processes, our approach intentionally aligns the second precursor of one subcycle with the first precursor of the next, thereby preoccupying interstitial sites and suppressing the nucleation delay. Applied to Indium-Tin-Zinc-Oxide (ITZO) thin films, this method produces denser films with fewer defects compared to the conventional supercycle process. The resulting enhancement-type ITZO thin-film transistors (TFTs) achieve superior electrical properties (mobility(μ): 27.31 cm2 V-1 s-1, drift of threshold voltage (ΔVth): +0.8 V/-0.4 V (@ ± 1 MV cm-1, 3600 s)). Beyond ITZO, this work establishes a universal framework for defect-suppressed growth of single-/multicomponent oxides via ALD, directly addressing a critical bottleneck in high-performance electronics manufacturing.

Multiple Phase Transition Induced Enhancement of Low-Temperature Thermoelectric Power in Ductile AgCuS-Based Thin Films.

The increasing demand for energy autonomy in microscale and wearable electronics has intensified research interest in thermoelectric thin-film-based power generators. However, the development of such devices is challenging due to the intrinsic brittleness of inorganic materials and the poor performance of thin films. Recently, Ag2S-based compounds have emerged as ductile thermoelectric semiconductors. Nonetheless, the thermoelectric performance of their thin films remains constrained, especially at low temperatures. Herein, we present a solution-processed fabrication of a high-performance AgCuS/Cu2S composite thin film operable below 100 °C. These composite thin films underwent multiple phase transitions below 100 °C, notably increasing the thermoelectric power factors. Furthermore, the films exhibited significant intrinsic stretchability up to a strain of 16.1% owing to their intrinsic ductility. Wrinkled thin-film-based devices demonstrated enhanced power generation owing to multiple phase transitions and retained properties under 30% stretching, highlighting the potential of these films as viable energy harvesters for emerging electronic systems.

Effect of Sulfurization Temperature on the Chemical Composition and Phase Transformation of CuAlS2 Thin Films Prepared by two-stage Vacuum Thermal Evaporation

The study examined the effect of sulfurization temperature on chemical composition, structural properties and morphological features of CuAlS2 thin films that had been prepared using two – step Vacuum Thermal Evaporation Technique. It was reported that metallic Cu – Al precursor layer first deposited onto soda – lime glass substrates before they were sulfurized and annealed at 573K, 673K, and 773K. The thin films were then characterized by X – ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy Dispersive X – ray Spectroscopy (EDS) to study their crystallographic phase, surface morphology and elemental composition respectively. XRD study disclosed the formation of a chalcopyrite tetragonal CuAlS2 phase with notable variations of crystallinity and lattice parameters as a function of temperature. SEM images revealed that the film morphologies were influenced by sulfurization temperature and EDS analysis suggested non – ideal stoichiometry as a result of incomplete sulfurization at lower temperatures. Overall, the findings highlighted the crucial role of sulfurization temperature in determining material properties. The study also highlighted the potentials of CuAlS2 thin films in optoelectronic devices, particularly solar cells and light- emitting diodes.

Effects of Latent Solvent Content on Tuning the Nanofiltration Performance of Nanofibrous Composite Membranes.

This study aims to optimize the application of electrospun nanofibrous substrates in thin-film composite (TFC) nanofiltration (NF) membranes for enhanced liquid separation efficiency by employing a method of effective welding between fibers using latent solvents. Polyacrylonitrile (PAN) nanofiber substrates were fabricated via electrospinning, and a dense polyamide selective layer was formed on their surface through interfacial polymerization (IP). The investigation focused on the effects of different solvent systems, particularly the role of dimethyl sulfoxide (DMSO) as a latent solvent, on the nanostructure and final membrane performance. The results indicate that increasing the DMSO content can enhance the greenness of the fabrication process, the substrate hydrophilicity, and the mechanical strength, while also influencing the thickness and morphology of the polyamide layer. At a DMSO rate of 30%, the composite membrane achieves optimal pure water permeability and high rejection rates; when the DMSO content exceeds 40%, structural inhomogeneity in the substrate membrane leads to an increase in defects, significantly deteriorating membrane performance. These findings provide theoretical insights and technical guidance for the application of electrospinning technology in designing efficient and stable NF membranes.

Regulation and enhancement of the optical performance of graphene oxide through Ni/Fe/Ag nanoparticles doping

Graphene oxide (GO) is a two-dimensional carbon material with a graphene-like structure and many oxygen-containing functional groups, and in recent years from research into the unique optical properties of GO, GO-based composite materials formed by combining with other materials have shown improved overall performance. Reported here is an investigation of how doping with Ni, Fe, and Ag nanoparticles affects the linear and nonlinear optical properties of GO films. The morphology and structure of films of GO, GO with Ni nanoparticles, GO with Fe nanoparticles, and GO with Ag nanoparticles were studied by laser scanning confocal microscopy, SEM, energy dispersive spectroscopy, XRD, and Raman spectroscopy. UV–visible absorption spectra were used to study the optical absorption properties, and the optical band gaps of GO and the composites were calculated from those spectra via Tauc plots. The results show that the band gaps of GO films can be effectively regulated by metal nanoparticles, and so the properties of GO composites can be manipulated. The nonlinear optical properties of GO and GO–metal-nanoparticle composite films were studied by femtosecond laser Z-scanning. The results show that the femtosecond laser power can be tuned to the optical limiting behavior of GO. The strong synergistic coupling effect between metal nanoparticles and GO enhances the nonlinear absorption and nonlinear refraction of composite thin films. The nonlinear absorption coefficient of the composite thin films is improved significantly, and the optical limiting properties are excellent. GO–metal-nanoparticle composite materials have potential applications and advantages in improving optical absorption, band-gap control, and optical limiting. They can promote the expansion of GO composite materials in various practical applications and are candidates for good optical materials, opening the way to GO photonics.

Networked cellulose-integrated highly permeable TFC polyamide membranes with tailored nanofiltration performance.

Networked cellulose-integrated highly permeable TFC polyamide membranes with tailored nanofiltration performance.

Thin-film composite membranes with tailored pore structures for enhanced gas separation performance

Thin-film composite membranes with tailored pore structures for enhanced gas separation performance

Nitrogen‐Doped Carbon Quantum Dot as Novel Nano Additive to Improve Performance and Fouling Resistance of Forward Osmosis Thin Film Nanocomposite Membranes

ABSTRACTForward osmosis (FO) is considered a strong and energy‐efficient desalination method. The thin film composite (TFC) membranes are widely used in the FO process. In this study, nitrogen‐doped carbon quantum dot (NCQD) was synthesized from citric acid (CA) and m‐phenylene diamine (MPD) as carbon and amine precursors, respectively, by a one‐step hydrothermal method. It was characterized completely by FT‐IR, XRD, UV–visible spectroscopy, DLS, and TEM analysis. Then, NCQD was incorporated in the polyamide (PA) layer to synthesize novel thin film nanocomposite (TFN) membranes. All membranes were analyzed by FT‐IR, WCA, AFM, and FE‐SEM. The TFN‐NCQD membrane, optimized with a concentration of 2000 ppm NCQD, exhibited outstanding FO performance, achieving a 70% increase in water flux compared to the pristine TFC. This membrane attained a peak water flux of 20.4 LMH, a reverse salt flux of 2.1 gMH, and showcased the best selectivity, with values as low as 0.10 g/L among the others. The strong interaction between amine functional groups of NCQD with both MPD and TMC during interfacial polymerization resulted in excellent adhesion and compatibility between the nanofiller and PA, increasing the lifespan of TFN membranes. Moreover, the novel TFN‐NCQD2 membrane showed better fouling behavior than pristine TFC, a 22% improvement when sodium alginate solution (600 ppm) was used as a foulant model.

High temperature resistant polyamide thin film composite nanofiltration membrane based on polyethylene substrate

High temperature resistant polyamide thin film composite nanofiltration membrane based on polyethylene substrate

Effect of the synthesis conditions on the composition, structure, and electromagnetic properties of Cd3As2 thin films

Effect of the synthesis conditions on the composition, structure, and electromagnetic properties of Cd3As2 thin films

Ionic covalent organic framework engineered super-charged thin-film composite polyamide membrane for desalination

Ionic covalent organic framework engineered super-charged thin-film composite polyamide membrane for desalination

Nanomorphogenesis of interlayered polyamide membranes for precise ion sieving in lithium extraction.

Nanomorphogenesis of interlayered polyamide membranes for precise ion sieving in lithium extraction.

The performance of a graphene oxide thin film composite membrane for sweet whey ultrafiltration

Membranes manufactured from graphene oxide (GO) have received significant attention for desalination and nanofiltration applications due to their exceptional mechanical strength, chemical stability and high selectivity. However, the performance of GO membranes in food processing applications is less well understood. In this work, the performance of a GO membrane, advertised as being of 1 kDa molecular weight cutoff, is compared to that of two commercial polymeric membranes of different molecular weight cut-off (advertised as 10 kDa and 1 kDa) for the ultrafiltration of sweet whey from the dairy industry. At bench scale, the GO membrane had comparable rejection for both total solids and protein to the 10 kDa polymeric membrane, but with more than double the flux, provided by a much lower intrinsic membrane resistance. Analysis of the membrane fouling process suggested that the GO membrane fouled more slowly than the 1 kDa polymeric membrane, but the fouling process was not significantly different to that reported in the literature for polymeric membranes in this application. Pilot scale trials conducted using a commercial spiral wound module of 1.2 m2 area of the GO membrane confirmed that the membrane retained a higher flux. This flux was, however, reduced from the bench scale value.

Recent progress in thin film composite membranes based on the polymer of intrinsic microporosity PIM-1: Preparation, properties and performance

Recent progress in thin film composite membranes based on the polymer of intrinsic microporosity PIM-1: Preparation, properties and performance

Morphological details of cellulose nanofibers and their composites for Raman sensing application.

Morphological details of cellulose nanofibers and their composites for Raman sensing application.

Bench-scale high-performance forward osmosis thin-film composite membranes for concentrating lithium ions with degradation of the mechanical properties

Bench-scale high-performance forward osmosis thin-film composite membranes for concentrating lithium ions with degradation of the mechanical properties

A laser ultrasound emitter based on high-power diode laser in overdrive operation mode for biomedical imaging applications.

A laser ultrasound emitter based on high-power diode laser in overdrive operation mode for biomedical imaging applications.

Synthesis and characterization of MXene/nanocrystalline cellulose composite thin films for enhanced electromagnetic interference shielding

Synthesis and characterization of MXene/nanocrystalline cellulose composite thin films for enhanced electromagnetic interference shielding

Enhanced optical and electrical properties of NiO-GO composite thin films on flexible PET substrates for optoelectronic applications

Enhanced optical and electrical properties of NiO-GO composite thin films on flexible PET substrates for optoelectronic applications