Trilayer Films Research Articles

Development of a Multilayer Film Including the Soluble Eggshell Membrane Fraction for the Treatment of Oral Mucosa Lesions

Background/Objectives: Oral diseases causing mucosal lesions are normally treated with local or systemic anti-inflammatory, analgesic and antimicrobial agents. The development of topical formulations, including wound-healing promoters, might speed up the recovery process, improving patients’ quality of life, and reduce the risk of deterioration in health conditions. In this study, a mucoadhesive multilayer film, including a novel biocompatible substance (solubilized eggshell membrane, SESM), was rationally designed. Methods: The SESM preparation procedure was optimized and its biological effects on cell proliferation and inflammation marker gene expression were evaluated in vitro; preformulation studies were conducted to identify the most promising polymers with film-forming properties; then, trilayer films, consisting of an outer layer including chlorhexidine digluconate as a model drug, a supporting layer and a mucoadhesive layer, incorporating SESM, were prepared using the casting method and their mechanical, adhesion and drug release control properties were evaluated. Results: SESM proved to possess a notable wound-healing capacity, inducing a wound closure of 84% in 24 h without inhibiting blood clotting. The films revealed a maximum detachment force from porcine mucosa of approx. 1.7 kPa and maximum in vivo residence time of approx. 200–240 min; finally, they released up to 98% of the loaded drug within 4 h. Conclusions: The formulated trilayer films were found to possess adequate properties, making them potentially suitable for protecting oral lesions and favoring their rapid healing, while releasing antimicrobial substances that might be beneficial in reducing the risk of bacterial infections.

Slurry Casted Ultrathin Li3Zr2Si2PO12 Electrolyte Film for Solid-State Lithium Metal Batteries.

Thin and flexible solid-state electrolyte (SSE) films with high ionic conductivity and low interfacial resistance are urgently required for lithium metal batteries (LMBs). However, it's still challenging to reduce the film thickness to <20µm, especially for those with high ceramic contents. Herein, a facile slurry casting method is developed to prepare the ultra-thin (14µm) Li3Zr2Si2PO12 (LZSP) films with ceramic content up to 91% using a composite polymer binder, polyvinylidene fluoride (PVDF), and polyethylene oxide (PEO). It shows that PEO not only enhanced the film flexibility but also makes it be easily peeled off to form a freestanding membrane, PLN. To promote the interfacial ion transport, PEO/lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) is introduced to the film surface, and the resultant tri-layer film, PPLN, shows a satisfying room temperature ionic conductivity of 0.116mScm-1, high Li+ transference number of 0.79, and good compatibility with metal lithium. As a result, LMBs using LiFePO4 cathode and PPLN electrolyte exhibit excellent safety as well as electrochemical performances in the wide temperature range between room temperature (RT) and 100°C.

Isothermal magnetization and magnetoresistive variations in trilayer (La2/3Sr1/3MnO3/γ-Fe2O3/La2/3Sr1/3MnO3) hetero-structure

We report the magnetic field dependent magnetization and magnetoresistance (MR) properties of La2/3Sr1/3MnO3 (LSMO)/ γ -Fe2O3/LSMO trilayer heterostructure and single layer LSMO film grown on SiO2/Si (100) substrates utilizing Pulsed Laser Deposition technique. The metal- insulator-metal configuration is a magnetic tunnel junction topology, which is a parallel network of two metallic layers (LSMO) and one insulating layer ( γ -Fe2O3) in current-in-plane (CIP) geometry. The intrinsically inhomogeneous polycrystalline trilayer film shows much lower (almost half ) coercivity, compared to single layer LSMO film. The MR-H [MR = (ρ (H)-ρ (0))/ρ (0)] behavior of the films is studied under two regimes namely, Low Field Magnetoresistance (LFMR) and High Field Magnetoresistance (HFMR) at 5 K and 300 K in the field range of 0–7 T. Several equations were developed to simulate the experimental MR-H data of the studied samples. For both the films, in the LFMR region (0 T < H ≤ 1 T @ 5 K), the variation in MR exhibits a linear increase with H, followed by a logarithmic behavior in the HFMR region (1 T < H ≤ 7 T @ 5 K). For the trilayer film in CIP geometry, a negative MR of 16% is achieved at 5 K and 1 T field conditions, while LSMO single layer shows a negative MR of 13% at same temperature and field conditions. The MR obtained at high field (7 T) for both the films is quantitatively equal with a value of 38% @ 5 K and 15% @ 300 K. We obtained significantly better MR-H results for the trilayer in current-perpendicular-to-plane (CPP) configuration, where the two metallic layers and an insulating layer are in series. In the CPP configuration, MR is 21% @ 5 K and 1 T field, while it reached to 44% at 5 K and 7 T field. At room temperature, the trilayer heterostructure shows MR of 17% at 7 T field condition. At a higher field of 9 T, trilayer film in CPP mode exhibits MR value of 48% @ 5 K and 23% @ 300 K. Further, the anti-parallel and parallel magnetization states of the MIM device are well manifested in CIP and CPP geometries.

Preparation of trilayer film with slow-release, antioxidant, and antibacterial activities and its effects on scallop preservation

Scallops are renowned for their delicious taste and rich nutritional profile, including high contents of eicosapentaenoic acid and docosahexaenoic acid. However, they are highly susceptible to spoilage caused by lipid oxidation and microorganism proliferation. Therefore, in this study, trilayer films based on gelatin/gelatin-dextran/gelatin with different concentrations (0%, 0.3%, 0.6%, 0.9%, and 1.2%, w/w) of active fillers (citronellal and α-tocopherol) were developed to preserve scallop adductor muscle during cold storage. Scanning electron microscopy images showed that each layer was well-bonded with no gaps, indicating the successful preparation of the trilayer films. The addition of citronellal and α-tocopherol resulted in a porous cross-section with a slightly rough surface and increased hydrophobicity of the trilayer films. With increase in concentrations of citronellal and α-tocopherol, the thickness, opacity, antioxidant capability, and antibacterial activity of the trilayer films increased, while water vapor permeability and mechanical properties decreased. Both citronellal and α-tocopherol showed controlled release properties in four food simulants, with the longest release times in 95% (v/v) ethanol solution. Furthermore, the incorporation of 1.2% (w/w) of active fillers into the trilayer film significantly enhanced the chemical and microbiological stabilities of the scallop adductor muscles, thereby prolonging their shelf life by six days during cold storage. The developed trilayer films showed excellent controlled release, antibacterial properties, and antioxidant capabilities, indicating their potential for effective preservation of aquatic food products.

Features of the Course of the Solid-State Reactions in a Sn/Fe/Cu Trilayer Film System

Features of the Course of the Solid-State Reactions in a Sn/Fe/Cu Trilayer Film System

Development and characterization of bioactive polyvinyl alcohol / chitosan multilayer-based films loaded with tea tree oil nanoemulsion to extend the shelf life of red grapes

This study presents a comprehensive overview of developing, characterizing, and utilizing trilayer antibacterial films for potential food preservation applications. The films are composed of chitosan (Ch) and polyvinyl alcohol (PVA) as biopolymers and tea tree essential oil nanoemulsion (NETTO) as the primary antibacterial ingredient. Initial evaluations confirmed tea tree oil's potent antimicrobial efficacy, demonstrating inhibitory and bactericidal effects against Escherichia coli and Staphylococcus aureus at low concentrations. The MIC values for E. coli were 2.5 μL/mL and for S. aureus 1.25 μL/mL, with corresponding MBC values of 5 μL/mL and 1.25 μL/mL, respectively. The incorporation of NETTO in the film formulation not only improves the antibacterial efficacy of the films, as evidenced by agar well diffusion assays, but also impacts their physical properties. The trilayer film also became less moisture-content15.59%, soluble 11.57 %, and permeable to water vapor 5.52 (10−5 gm−1 min−1 Pa−1). The trilayer film can provide sustained release and better tea tree oil retention rates than the Ch-NETTO film. The study further investigates the effectiveness of trilayer film in preserving red grapes, which outperformed commercial plastic and Ch films against S. aureus and E. coli bacteria. The trilayer film effectively preserves the appearance and freshness of red grapes, extending their shelf life.

Multi-level phase-change behaviors of Ge2Sb2Te5/Sb7Se3 bilayer films and a design rule of multi-level phase-change films

Multi-level phase-change (MLPC) memory can not only further raise the storage density of high-density phase-change memory, but also have significant applications in neuromorphic computing. However, acquisitions of MLPC materials are very challenging. MLPC is only observed in a small number of phase-change materials and can’t be designed determinately because the mechanism of MLPC emergence has been understood incompletely. Here, we investigate phase-change behaviors of six Ge2Sb2Te5(x nm)/Sb7Se3 (60-x nm) bilayer films with x = 5, 10, 15, 20, 35, and 50. Three-level phase-change memory is observed for five bilayer films with x < 50, but not for one with x = 50, revealing the dependence of MLPC memory on the thickness ratio of two constituent layers composing bilayer films. A parallel resistance model is proposed to describe the measured sheet resistance of bilayer films and can be used to explain the thickness-ratio dependence of three-level phase-change memory very well. Subsequently, a design rule for MLPC memory films is given out unambiguously. Based on the parallel resistance model, MLPC memories are simulated for bilayer and trilayer films. Three-level memory indeed appears in bilayer films only when the design rule is met, confirming the validity of our design rule. Four-level memory is predicted in trilayer films as the design rule is obeyed.

A Tri-Layer Structural Film Containing Nickel Nanocoating for Electromagnetic Transmittance and Joule Heating

A Tri-Layer Structural Film Containing Nickel Nanocoating for Electromagnetic Transmittance and Joule Heating

Coextruded polylactide/encapsulated cinnamon essential oil/graphene nanoplatelets trilayer films: Morphological, barrier, thermal, rheological and antimicrobial properties

AbstractPolylactide (PLA)‐based biodegradable three‐layer packaging film was fabricated using PLA, PLA/cinnamon oil (CEO), and PLA/graphene nanoplatelets (GNP). The central layer allows control over the release of antimicrobes, and the outer layer adds mechanical strength to the films. A comparison has been made on barrier, thermal, rheological, microstructural, and microbiological properties between single‐layer and multilayer films (MLF). The water vapor and oxygen barrier properties of MLF showed little reduction compared with those of neat PLA. The tensile stress of the neat PLA increased significantly from 23.31 to 35.91 MPa for the MLF. Thermal analysis data showed improvements in the thermal stability of the MLF film, with onset and peak temperatures of 331.5 and 357.1°C, respectively. The dispersion of GNP in the PLA matrix and in MLF was assessed by XRD analysis and rheological measurement. The AFM roughness parameters Sa and Sq of those films varied widely, with the highest (13.9 and 20.9 μm) and the lowest (0.08 and 0.11 μm) magnitudes recorded for PLA/GNP and PLA/CEO films, respectively. Antibacterial assays of the film confirmed a strong bactericidal effect against Listeria monocytogenes and Salmonella typhimurium, maintaining this activity for 21 days.Highlights Polylactide/cinnamon oil/ graphene nanoplatelet multilayer films were coextruded. X‐ray diffraction and rheology confirm the dispersion of graphene into PLA. Tensile stress and thermal stability improved in the multilayer films. AFM roughness parameters varied significantly between single‐ and multilayer films. Antibacterial assays confirmed the strong bactericidal effect of films against pathogens.

Rupture of thin liquid trilayer films with soluble surfactants: fundamentals and applications to droplet coalescence.

Understanding the stability of thin liquid trilayer films is of direct relevance to applications such as multilayer coatings and polymer processing. The stability of trilayer films can also be used to provide insights into emulsion dynamics, such as the rupture of the thin film formed between two droplets during coalescence. Often, emulsions are laden with surfactants and other additives, which can be present in one or both phases as well as at the interfaces between the liquids. In experimental studies, complicating factors such as variations in droplet sizes, curvatures, and collision processes make it difficult to specifically isolate the influence of surfactant transport on droplet coalescence and film rupture. The present work addresses this issue by systematic consideration of a model problem involving a thin liquid trilayer film. Surfactant is soluble in either the outer layers or the inner layer, corresponding to surfactant soluble in the droplets or the continuous phase. Rupture of the inner layer is driven by van der Waals forces. Lubrication theory is applied to derive coupled nonlinear evolution equations describing the perturbations to the interface positions and the surfactant concentrations. Our findings reveal that surfactant better stabilizes the film when soluble in the inner layer, and the stabilizing effect is more pronounced when the outer layers are thicker. These findings are consistent with experimental observations involving emulsions, where emulsions tend to be more stable when surfactant is in the continuous phase rather than in the droplets, with the distinction being more pronounced when droplets are larger.

Tri-layer high-temperature all-organic films with superior energy-storage density and thermal stability

Tri-layered all-organic composites exceed the upper energy-storage-density limits of commercial bench-mark BOPP (∼1.4 J cm−3) and representative ferroelectric polymer-based composites (&lt;4 J cm−3) at elevated temperature.

In situ wrapping carbon dots towards robust, durable and transparent tri-layer films with precise spectral conversion and excellent self-cleaning properties

Based on solid-state fluorescent emission CDs, PDMS and hydrophobic fumed silica, the robust and transparent tri-layer films with UV-to-red spectral conversion and excellent superhydrophobic self-cleaning properties were designed and fabricated.

Heteroepitaxial Growth of Black Phosphorus on Tin Monosulfide.

Black phosphorus (Black P), a layered semiconductor with a layer-dependent bandgap and high carrier mobility, is a promising candidate for next-generation electronics and optoelectronics. However, the synthesis of large-area, layer-precise, single crystalline Black P films remains a challenge due to their high nucleation energy. Here, we report the molecular beam heteroepitaxy of single crystalline Black P films on a tin monosulfide (SnS) buffer layer grown on Au(100). The layer-by-layer growth mode enables the preparation of monolayer to trilayer films, with band gaps that reflect layer-dependent quantum confinement.

Residual stress and thickness effects on fracture behavior of trilayer films during uniaxial loading

The effects of residual stress and film thickness on crack evolution in metallic trilayers deposited on polyimide substrate have been investigated during uniaxial tensile loading. Four different systems, consisting of Mo/Cu/Cr layers deposited on polyimide, with nominal thicknesses of 100/100/100 or 100/500/100 nm, were developed using two physical vapor deposition techniques, resulting in opposite as-deposited high residual stress for the top Cr layer (about +2.7 GPa versus -2.6 GPa). First, it was found that the higher the compressive residual stress of the top Cr layer and the thickness of the middle Cu layer, the higher the critical strain to initiate crack propagation in the trilayer film system. Second, it was found that the higher the compressive residual stress of the top Cr layer and the thickness of the middle Cu layer, the lower the maximum crack density in the trilayers. The maximum crack density in the thicker system with Cr in a tensile residual stress was similar to the maximum crack density in the thinner system with the Cr top layer in a compressive residual stress.

Synergically improved energy storage performance and stability in sol–gel processed BaTiO 3/(Pb,La,Ca)TiO 3/BaTiO 3 tri-layer films with a crystalline engineered sandwich structure

Synergically improved energy storage performance and stability in sol–gel processed BaTiO ₃/(Pb,La,Ca)TiO ₃/BaTiO ₃ tri-layer films with a crystalline engineered sandwich structure

A nonvolatile memory element for integration with superconducting electronics

We demonstrate a nonvolatile cryogenic magnetic memory element needed to support emerging superconducting- and quantum-computing technologies. The central element is a switchable tri-layer thin film magnetic dot comprising two semiconducting ferromagnetic GdxSm1−xN layers separated by an exchange-blocking Al layer. The materials are explored for their tunable magnetic responses, the potential to engineer compensating magnetic moments in the anti-parallel tri-layers. The stability of the parallel and anti-parallel states and the reproducibility over repeated cycles are also demonstrated. We show that the tri-layer stacks can be formed into dots as small as 4 μm diameter, without affecting their magnetic behavior.

Improved energy density and efficiency of polymer nanocomposites by filling ultralow amounts of 2D Ni(OH)2 nanosheets and building sandwich structure

Currently, the application of polymer dielectric capacitors is largely limited by their low energy storage density. Herein, novel sandwich-structured composite films with simultaneously enhanced energy storage density and efficiency are fabricated, which combine outer layers of inorganic nanosheets Ni(OH)2/poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) with high permittivity and intermediate layer of polycarbonate (PC) with high breakdown strength. The trilayer film with only 1 vol% Ni(OH)2 exhibits an excellent energy storage density of 7.322 J/cm3 accompanied with a high efficiency of 72.1 % at 605 kV/mm, which are 120 % and 113 % of pure P(VDF-HFP). Furthermore, hindrance effect of micro-interfaces and macroscopical-interfaces on electrical trees is well revealed through finite element simulation. These excellent characteristics of composite films suggest that this design strategy is effective to realize concurrent high energy density and efficiency.

Circular Economy Insights on the Suitability of New Tri-Layer Compostable Packaging Films after Degradation in Storage Conditions.

The environmental degradation of the films used in packaging is a key factor in their commercial use. Industrial and academic research is aimed at obtaining materials that have degradation features that ensure their eco-sustainability but, at the same time, preserve their use properties during storage and distribution periods. This study analyzes the degradability behavior over time of commercial packaging that meets the requirements of the UNE 13432 standard and the prEN 17427 (2020) home composting certification requirements under standard storage conditions. The study attempts to provide insight into the durability of the films under standard storage conditions, verifying that this type of packaging has a useful life of more than 12 months and that after this storage period it still retains the usability properties for which it was conceived. The analyzed sample has been manufactured using a three-layer technology under some commercial formulations based on PBAT + STARCH + PLA and has been analyzed monthly for 12 consecutive months. The macroscopic monitoring of the degradation of the sample has been carried out through the evolution of the mechanical properties and the quantification of the color changes (very important in films) via colorimetry. The nature of the observed variations has been justified at the microstructural level from the data obtained in calorimetric analysis (DSC) and from the characterization using FTIR. The results indicate a loss of properties in the tensile, elongation and impact tests and a behavior of stability or improvement in the tear properties of the film. Analyzing the microstructural changes, it is observed that the degradation of a hydrolytic and thermo-oxidative type occurs in the amorphous part of the film. The conclusion of this study is that the proposed packaging, focused on domestic composting and stored under standard conditions, has a useful life of more than 12 months. This period should be sufficient to cover the stages of production, storage and final use.

Morphological, thermo-mechanical, and barrier properties of coextruded multilayer polylactide composite films reinforced with graphene nanoplatelets and encapsulated thyme essential oil

The food industry has been looking for biodegradable active packaging film, which has a lower environmental footprint and can extend shelf-life. This work aimed to develop a polylactide-based antibacterial nanopackaging with a tri-layer structure. This coextruded tri-layer film was composed of an internal extruded layer of polylactide (PLA), a central layer of PLA loaded with encapsulated thyme essential oil, and an outer layer of PLA with graphene nanoplatelets. The tri-layer packaging films' morphological, rheological, thermal, barrier, and antibacterial properties were evaluated and compared to those of their single-layer counterparts. Dispersion of nanoparticles in PLA matrix or in composites is described by rheological, thermal, and XRD analysis. The multilayer films displayed some roughness on the surface, and heterogeneity can be seen through phase imaging compared to single-layer films. Antibacterial assays of the film confirmed a strong bactericidal effect against gram-positive and gram-negative bacteria, maintaining this activity for 21 days.

Is it meaningful to quantify vacancy concentrations of nanolamellar (Ti,Al)N thin films based on laser-assisted atom probe data?

Recently, it was proposed to quantify vacancy concentrations based on laser-assisted atom probe tomography (APT) data for a (Ti,Al)N film with a nanolamellar architecture, grown by chemical vapor deposition. To determine, whether vacancy concentrations can be reliably estimated based on APT data, we systematically compare measurements with an ultraviolet (UV) as well as a green laser to ion beam analysis data. First, monolithic TiN and AlN films, which are stoichiometric within the measurement uncertainties of ion beam analysis, are investigated. In case of TiN an electric field strength of 39.4 V nm−1 and a nitrogen content of 49.0 at.%, consistent with ion beam analysis data, is obtained with both lasers, when using pulse energies of 5 pJ (UV laser) and 0.1 nJ (green laser). However, significant differences can be observed for monolithic AlN as nitrogen contents from 41.9 to 35.8 at.% and 48.4 to 41.4 at.% are measured, depending on variations of the pulse energies of the UV and green laser, respectively. In order to mimic a nanolamellar architecture for correlative compositional analysis by ion beam analysis and laser-assisted APT, a TiN/AlN/TiN trilayer film is synthesized and significant deviations with respect to the nitrogen content are evident for the AlN layer. While the average nitrogen concentration from ion beam analysis is 51 at.%, nitrogen contents from laser-assisted APT data are only 38 at.% (UV laser) or 41 at.% (green laser). Hence, the nitrogen content of the AlN layer is underestimated from laser-assisted APT data by at least 10 and up to 13 at.% and this significant discrepancy cannot be explained by the measurement uncertainties. Thus, the here presented data emphasize that it is not meaningful to quantify vacancy concentrations of nanolamellar (Ti,Al)N thin films solely based on atom probe data, since the measurement accuracy depends on the field evaporation conditions.