Composite Thin Films Research Articles

Co-deposition enhances electrodialysis of thin film composite (TFC) membranes for efficient separation of Cl−/SO42-

Co-deposition enhances electrodialysis of thin film composite (TFC) membranes for efficient separation of Cl−/SO42-

A review on antifouling polyamide reverse osmosis membrane for seawater desalination.

A review on antifouling polyamide reverse osmosis membrane for seawater desalination.

High performance polyester TFC membrane fabricated using vapor-based interfacial polymerization technique for saline water recovery

High performance polyester TFC membrane fabricated using vapor-based interfacial polymerization technique for saline water recovery

Mild synthesis of bi-carboxylated COFs nanosheets for the preparation of high-efficiency nano-wrinkled TFN membrane

Mild synthesis of bi-carboxylated COFs nanosheets for the preparation of high-efficiency nano-wrinkled TFN membrane

Highly Efficient and Flexible Thin Film Thermoelectric Materials from Blends of PEDOT:PSS and AgSb0.94Cd0.06Te2

AbstractMechanically stable and flexible composite TE thin films based on PEDOT:PSS and AgSb0.94Cd0.06Te2 blend by hot pressing on porous PVDF substrate are fabricated. A considerable enhancement of S and σ is observed in the regime of 60–97.5 wt.% of AgSb0.94Cd0.06Te2. High Seebeck coefficients of up to 204.9 µV K−1 and a high‐power factor of 53.45 µW m−1 K−2 are obtained for 97.5 wt.% of AgSb0.94Cd0.06Te2 content. However, there is a decrease in electrical conductivity on bending or storage under air. No loss of mechanical integrity can be detected in the SEM of bent films. Ultraviolet photoelectron spectroscopy reveals that overall energy levels of composite systems are either similar to PEDOT:PSS (φ = 5.00 ± 0.16 eV, IP = 5.12 ± 0.02 eV) or AgSb0.94Cd0.06Te2 (φ = 4.43 ± 0.11 eV, IP = 4.57 ± 0.01 eV), depending on the blend ratio. Transport mechanisms are studied using Mott–Schottky measurements, and by calculating the weighted charge carrier mobility, which increases continuously up to 5.5 cm2 V−1 s−1 for the highest inorganic content. It is demonstrated that a high inorganic content TE composite results in a flexible TE film achieving 80% of the Seebeck value of the pure inorganic component.

Bioactive Glass and Melittin Thin Films Deposited by MAPLE for Titanium Implant Functionalization.

The development of bioactive coatings for metallic implants is essential to enhance osseointegration and improve implant longevity. In this study, composite thin films based on bioactive glass and melittin were synthesized using the matrix-assisted pulsed laser evaporation technique and deposited onto titanium substrates. The coatings were characterized using physicochemical analysis methods, including scanning electron microscopy, atomic force microscopy, contact angle measurements, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, and electrochemical impedance spectroscopy. Simulated body fluid immersion tests were also conducted to assess bioactivity over time. Scanning electron microscopy and atomic force microscopy revealed dense, irregular surface textures with nanoscale features and an average roughness of ~120 nm, favorable for cell adhesion. Contact angle measurements showed a significant shift from hydrophobic (~95° for bare titanium) to moderately hydrophilic (~62° for the bioglass and melittin coating) surfaces, indicating improved biocompatibility. Electrochemical impedance spectroscopy demonstrated enhanced corrosion resistance in simulated body fluid, with the coating exhibiting a ~45% decrease in impedance magnitude after 12 h of immersion, compared to only 4% for bare titanium. Fourier transform infrared spectroscopy and energy-dispersive X-ray spectroscopy analyses confirmed the progressive formation of a carbonated apatite layer after 7 days of simulated body fluid exposure, suggesting high bioactivity and osteoconductive potential. The combined effects of bioactive glass and melittin in the thin film structure offer promising applications in orthopedic and dental implants, enhancing both biological performance and structural integrity.

Composite materials based on Ni0.5Zn0.5Fe2O4 ferrite: preparation and microwave properties

This work presents the synthesis of ferrite with the composition Ni0.5Zn0.5Fe2O4, its investigation by SEM, XRD, TGA, IR-Fourier methods, and the preparation of thin composite films using PVC as the base material and ferrite as a filler. It was found that the average crystal sizes are approximately 29.8 ± 0.2 nm and 31.3 ± 0.1 nm for Ni0.5Zn0.5Fe2O4 powder, respectively. The radio-absorbing properties of the resulting films in the X-band were investigated. Radiotransparent in the X-band composite material based on PVC/Ni0.5Zn0.5Fe2O4 ferrite with a weak dependence of the reflection value on the concentration of the filler (ferrite) was obtained.

Synthesis And Physical Properties of Cadmium Sulphur (Cds) Nanoparticles

In this article, we present a simple and less hazardous route for the synthesis of CdS nanoparticles. We use the coprecipitation method for the synthesis of CdS nanoparticles, and obtain nanoparticles by calcination at 400°C. The synthesized CdS nanoparticles were characterized by optical microscopy and X-ray diffraction. The uniqueness of hexagonal (Wurtzite) CdS was revealed by X-ray diffraction peaks. The article also presents a study of the optical and electrical properties of polymer suspensions containing carbon nanotubes and composites based on them. These suspensions were also used to obtain composite thin films. Carbon nanotubes are of great interest in science and technology due to the combination of outstanding mechanical and electrical properties, extremely large interfacial contact area, high aspect ratio and low mass density. The use of nanotube concentrations as fillers in various composites, even less than 1 wt.%, has a significant impact on the optoelectronic properties of the final devices, making their use in nanoelectronics applications promising.

Assessment of permeance and selectivity of thin-film composite polyamide membranes for diverse applications

Assessment of permeance and selectivity of thin-film composite polyamide membranes for diverse applications

Thin-film composite vapor-gap membrane for pressure-driven distillation.

Pressure-driven distillation (PD), as an emerging technology, holds tremendous potential for producing freshwater from nontraditional water sources. In this process, a sufficient hydraulic pressure is applied to drive water evaporation and vapor transport across a vapor-gap membrane. The development of the PD process critically depends on the availability of robust and large-area superhydrophobic membranes. Here, we propose an ultraselective superhydrophobic thin-film composite (TFC) vapor-gap membrane with confined transport channels toward the PD process, which can be manufactured scale-up through a facile swelling-assisted deposition strategy. The TFC-PD membrane demonstrates separation capabilities, achieving near-complete rejections of nonvolatile solutes, including salts, boron, and urea. Featured by a vapor-gap superhydrophobic layer, the TFC-PD membrane exhibits superior chlorine and scaling resistance and maintains stable performance over time without being oxidized or scaling. This work offers notable advancements in the microstructural design of PD membranes and the development of scalable robust TFC membranes for the PD process.

Tunable Hydrated Channels in Covalent Organic Framework Membrane for Seawater Desalination.

Nanofiltration and reverse osmosis (RO) are instances of pressure-driven membrane desalination processes (PMDs), which have been extensively employed for seawater desalination due to their great efficiency and environmental friendliness. However, the PMD process is usually limited to thin-film composite polyamide membranes, despite enormous research efforts in recent decades. Here, light-controlled RO COF membranes are developed by using a defect-engineered strategy to chemically rivet spiropyran units into COF channels. The spatial arrangement of spiropyran provides the defect-engineered COF membranes with manageable apertures spanning from 6.9 to 11.1 Å. The COF membrane featuring ordered ultramicropores (6.9 Å, TAPA-TFP-SP-25% COFs) exhibits a preeminent desalinization performance with a NaCl rejection of 91.2%. Furthermore, under light stimulation, the COF channels decorated with spiropyran units are capable of self-regulating the framework structure and hydration conformation by controlling the interconnectivity of confined water clusters, thus achieving hydrated pore size tuning from 11.1 to ∼4.0 Å (from TAPA-TFP-SP-50% to TAPA-TFP-MC-50% COF membrane). Under dark conditions, zwitterionic COF membranes after photoisomerization (TAPA-TFP-MC-50%) exhibit an enhanced KCl rejection (96.2%), representing a 24.1% increase when compared to the COF membrane without interconnected hydrated channels (TAPA-TFP-SP-50%). This membrane channel design concept exploits a viable avenue for developing RO membranes to achieve efficient water purification.

Photothermal-Assisted Interfacial Polymerization toward Microstructure Regulation of a Polyamide Membrane with Enhanced Separation Performance.

A highly permeable thin-film composite (TFC) polyamide membrane with efficient salt rejection is valuable for numerous industrial processes. To achieve this objective, it is essential to innovate the membrane fabrication process to produce an ultrathin polyamide separation layer. In this study, a photothermal-assisted interfacial polymerization (IP) strategy was proposed to fabricate TFC polyamide membranes by incorporating carboxylated carbon nanotubes (CNTs) with exceptional photothermal properties. CNTs absorb solar energy and convert it into heat, significantly elevating the temperature in their microregions, thereby accelerating the reaction between m-phenylenediamine (MPD) and trimesoyl chloride (TMC) during the IP process. Exploiting the self-inhibition characteristics of IP, the preformed polyamide layer suppresses the subsequent diffusion of MPD into the reaction interface, resulting in the formation of an ultrathin polyamide layer. Consequently, the CNTs-modified polyamide membrane with photothermal assistance obtains a thickness of approximately 94 nm, significantly thinner than the control membrane (189 nm). Furthermore, it demonstrates a superior water flux of 54.4 L m-2 h-1, higher than that of the pristine TFC membrane without CNTs and the conventional CNTs-modified membrane, while maintaining a NaCl rejection of ∼96%. The photothermal-assisted IP strategy provides some inspiration for engineering high-performance polyamide membranes available in various advanced separations.

Review of Magnetoelectric Effects on Coaxial Fibers of Ferrites and Ferroelectrics

Composites of ferromagnetic and ferroelectric phases are of interest for studies on mechanical strain-mediated coupling between the two phases and for a variety of applications in sensors, energy harvesting, and high-frequency devices. Nanocomposites are of particular importance since their surface area-to-volume ratio, a key factor that determines the strength of magneto-electric (ME) coupling, is much higher than for bulk or thin-film composites. Core–shell nano- and microcomposites of the ferroic phases are the preferred structures, since they are free of any clamping due to substrates that are present in nanobilayers or nanopillars on a substrate. This review concerns recent efforts on ME coupling in coaxial fibers of spinel or hexagonal ferrites for the magnetic phase and PZT or barium titanate for the ferroelectric phase. Several recent studies on the synthesis and ME measurements of fibers with nickel ferrite, nickel zinc ferrite, or cobalt ferrite for the spinel ferrite and M-, Y-, and W-types for the hexagonal ferrites were considered. Fibers synthesized by electrospinning were found to be free of impurity phases and had uniform core and shell structures. Piezo force microscopy (PFM) and scanning microwave microscopy (SMM) measurements of strengths of direct and converse ME effects on individual fibers showed evidence for strong coupling. Results of low-frequency ME voltage coefficient and magneto-dielectric effects on 2D and 3D films of the fibers assembled in a magnetic field, however, were indicative of ME couplings that were weaker than in bulk or thick-film composites. A strong ME interaction was only evident from data on magnetic field-induced variations in the remnant ferroelectric polarization in the discs of the fibers. Follow-up efforts aimed at further enhancement in the strengths of ME coupling in core–shell composites are also discussed in this review.

Nodular networks in hydrated polyamide desalination membranes enhance water transport.

For nearly half a century, thin-film composite reverse osmosis membranes have served as key separation materials for desalination. However, the precise structure of their polyamide selective layer under hydrated conditions and its relationship to membrane transport remain poorly understood. Using cryo-electron tomography, we successfully reconstructed the three-dimensional structure of six commercial polyamide membranes under hydrated conditions, revealing a fully swollen nodular network. The highly heterogeneous nodules, measuring 17.2±2.8nanometer in thickness, were directly connected to the pores of the underlying polysulfone substrate. The nodules occupied most of the surface area compared to the 75.9±26.8-nanometer-thick dense layer of the polyamide film. Key structural parameters of the nodules, including surface area index and wall thickness, were correlated with the water permeance of an additional 16 polyamide membranes, validating the major role of these nodules in water transport. This study enhances our understanding of the heterogeneous structure of desalination membranes and its role in membrane transport.

Solvent-assisted insertion of molecular supports for enhanced separation performance and stability of thin film composite reverse osmosis membranes

Solvent-assisted insertion of molecular supports for enhanced separation performance and stability of thin film composite reverse osmosis membranes

X-ray photoelectron spectroscopy Reveals the chemical composition of antimicrobial Self-Assembled thin films containing the LL-37 peptide

X-ray photoelectron spectroscopy Reveals the chemical composition of antimicrobial Self-Assembled thin films containing the LL-37 peptide

Elemental distribution and phase composition of Pd-Gd thin films

Elemental distribution and phase composition of Pd-Gd thin films

Customizing the structure and performance of thin-film composite nanofiltration membranes for water treatment with 1D nanomaterial interlayers: A review

Customizing the structure and performance of thin-film composite nanofiltration membranes for water treatment with 1D nanomaterial interlayers: A review

Self-healing composite VO2 thin film with a thermochromic sandwich structure for smart windows

Self-healing composite VO2 thin film with a thermochromic sandwich structure for smart windows

Disentangling the gap between pure and mixed-gas performance of thin film composite membranes through improved cell design and testing methods

Disentangling the gap between pure and mixed-gas performance of thin film composite membranes through improved cell design and testing methods