Monoclinic LaSb2 Superconducting Thin Films.

Rare-earth diantimondes exhibit coupling between structural and electronic orders, which are tunable under pressure and temperature. Here we present the discovery of a new polymorph of LaSb2 stabilized in thin films synthesized using molecular beam epitaxy. Using diffraction, electron microscopy, and first-principles calculations we identify a YbSb2-type monoclinic lattice as a yet-uncharacterized stacking configuration. The material hosts superconductivity with a Tc = 2 K, which is enhanced relative to the bulk ambient phase, and a long superconducting coherence length of 1730 Å. This result highlights the potential thin film growth has in stabilizing novel stacking configurations in quasi-two-dimensional compounds with competing layered structures.

Nanostructured ZnO thin film to enhance gutta-percha's adhesion to endodontic sealers.

BACKGROUND: Gutta-percha (GP) combined with an endodontic sealer is still the core material most widely used for tridimensional obturation. The sealer acts as a bonding agent between the GP and the root dentinal walls. However, one of the main drawbacks of GP core material is the lack of adhesiveness to the sealer. ZnO thin films have many remarkable features due to their considerable bond strength, good optical quality, and excellent piezoelectric, antibacterial, and antifungal properties, offering many potential applications in various fields. This study aimed to explore the influence of GP surface's functionalization with a nanostructured ZnO thin film on its adhesiveness to endodontic sealers. METHODS: Conventional GP samples were divided randomly into three groups: (a) Untreated GP (control); (b) GP treated with argon plasma (PT); (c) Functionalized GP (PT followed by ZnO thin film deposition). GP's surface functionalization encompassed a multi-step process. First, a low-pressure argon PT was applied to modify the GP surface, followed by a ZnO thin film deposition via magnetron sputtering. The surface morphology was assessed using SEM and water contact angle analysis. Further comprehensive testing included tensile bond strength assessment evaluating Endoresin and AH Plus Bioceramic sealers' adhesion to GP. ANOVA procedures were used for data statistical analysis. RESULTS: The ZnO thin film reproduced the underlying surface topography produced by PT. ZnO thin film deposition decreased the water contact angle compared to the control (p < 0.001). Endoresin showed a statistically higher mean bond strength value than AH Plus Bioceramic (p < 0.001). There was a statistically significant difference between the control and the ZnO-functionalized GP (p = 0.006), with the latter presenting the highest mean bond strength value. CONCLUSIONS: The deposition of a nanostructured ZnO thin film on GP surface induced a shift towards hydrophilicity and an increased GP's adhesion to Endoresin and AH Bioceramic sealers.

Arrays of Bowl-Shaped Janus Particle Film with Structured Colors.

Structural colors generated via total internal reflection (TIR) using nanostructure-free micro-concave shapes have garnered increasing attention. However, the application of large micro-concave structures for structural coloration remains limited. Herein, a flexibly tunable structural color film fabricated by casting polydimethylsiloxane (PDMS) on an array of large poly(glycidyl methacrylate) (PGMA) bowl-shaped particles is reported. The resultant film exhibits tunable red to green structural colors with changing observation angles. Moreover, the color can be further tailored by altering the shape of the film itself. The incorporation of the PDMS layer not only facilitates a shift in the locus of TIR from the bottom surface to the top concave surface of the particles, thereby enabling the generation of structural color, but also confers enhanced flexibility to the film. Further decoration with silver nanoparticles imparts antimicrobial properties, yielding a novel antimicrobial coating material with structural colors. The simple and cost-effective strategy for the production of structural color films provides potential applications in antimicrobial coatings, enabling accessible and customizable structural coloration using big-size micro-concave particles.

PBAT/lignin-ZnO composite film for food packaging: Photo-stability, better barrier and antibacterial properties.

When PBAT used as film, stability deteriorates under sunlight exposure, the poor barrier and antibacterial properties are also limiting its application. In this work, lignin-ZnO nanoparticles were prepared by hydrothermal method, as additives to fill the PBAT matrix. In addition, PBAT-lignin-ZnO composite films were successfully prepared by melting and hot-pressing method. It is found that lignin could well dispersed the ZnO when its implantation into PBAT films, and lignin-ZnO not only maintaining tensile strength and thermal stability, but also could prompt PBAT's crystallinity. Especially, P-L-ZnO-2 composite films have good photostability. After 60 h aging, it can still maintain good molecular weight, chemical structure and mechanical properties. Besides, these composite films have improved hydrophobicity, barrier and antibacterial properties, could prevent mildew and significantly reduce the weight loss rate, color difference and hardness changes of strawberries during storage. This work provides a potential film material for outdoor applications and food packaging.

Multifunctional Film Assembled from N-Doped Carbon Nanofiber with Co-N4-O Single Atoms for Highly Efficient Electromagnetic Energy Attenuation.

Single-atom materials have demonstrated attractive physicochemical characteristics. However, understanding the relationships between the coordination environment of single atoms and their properties at the atomic level remains a considerable challenge. Herein, a facile water-assisted carbonization approach is developed to fabricate well-defined asymmetrically coordinated Co-N4-O sites on biomass-derived carbon nanofiber (Co-N4-O/NCF) for electromagnetic wave (EMW) absorption. In such nanofiber, one atomically dispersed Co site is coordinated with four N atoms in the graphene basal plane and one oxygen atom in the axial direction. In-depth experimental and theoretical studies reveal that the axial Co-O coordination breaks the charge distribution symmetry in the planar porphyrin-like Co-N4 structure, leading to significantly enhanced dielectric polarization loss relevant to the planar Co-N4 sites. Importantly, the film based on Co-N4-O/NCF exhibits light weight, flexibility, excellent mechanical properties, great thermal insulating feature, and excellent EMW absorption with a reflection loss of - 45.82 dB along with an effective absorption bandwidth of 4.8 GHz. The findings of this work offer insight into the relationships between the single-atom coordination environment and the dielectric performance, and the proposed strategy can be extended toward the engineering of asymmetrically coordinated single atoms for various applications.

Biomimetic Octopus Suction Cup with Attachment Force Self-Sensing Capability for Cardiac Adhesion.

This study develops a biomimetic soft octopus suction device with integrated self-sensing capabilities designed to enhance the precision and safety of cardiac surgeries. The device draws inspiration from the octopus's exceptional ability to adhere to various surfaces and its sophisticated proprioceptive system, allowing for real-time adjustment of adhesive force. The research integrates thin-film pressure sensors into the soft suction cup design, emulating the tactile capabilities of an octopus's sucker to convey information about the contact environment in real time. Signals from sensors within soft materials exhibiting complex strain characteristics are processed and interpreted using the grey wolf optimizer-back propagation (GWO-BP) algorithm. The tissue stabilizer is endowed with the self-sensing capabilities of biomimetic octopus suckers, and real-time feedback on the adhesion state is provided. The embedding location of the thin-film pressure sensors is determined through foundational experiments with flexible substrates, standard spherical tests, and biological tissue trials. The newly fabricated suction cups undergo compression pull-off tests to collect data. The GWO-BP algorithm model accurately identifies and predicts the suction cup's adhesion force in real time, with an error rate below 0.97% and a mean prediction time of 0.0027 s. Integrating this technology offers a novel approach to intelligent monitoring and attachment assurance during cardiac surgeries. Hence, the probability of potential cardiac tissue damage is reduced, with future applications for integrating intelligent biomimetic adhesive soft robotics.

Scalable Fabrication of Quasi-One-Dimensional van der Waals Ta2Pt3Se8 Nanowire Thin Films via Solution Processing for NO2 Gas Sensing over Large Areas.

Solution-based processing of van der Waals (vdW) one- (1D) and two-dimensional (2D) materials is an effective strategy to obtain high-quality molecular chains or atomic sheets in a large area with scalability. In this work, quasi-1D vdW Ta2Pt3Se8 was exfoliated via liquid phase exfoliation (LPE) to produce a stably dispersed Ta2Pt3Se8 nanowire solution. In order to screen the optimal exfoliation solvent, nine different solvents were employed with different total surface tensions and polar/dispersive (P/D) component (P/D) ratios. The LPE behavior of Ta2Pt3Se8 was elucidated by matching the P/D ratios between Ta2Pt3Se8 and the applied solvent, resulting in N-methyl-2-pyrrolidone (NMP) as an optimal solvent owing to the well-matched total surface tension and P/D ratio. Subsequently, Ta2Pt3Se8 nanowire thin films are manufactured via vacuum filtration using a Ta2Pt3Se8/NMP dispersion. Then, gas sensing devices are fabricated onto the Ta2Pt3Se8 nanowire thin films, and gas sensing property toward NO2 is evaluated at various thin-film thicknesses. A 50 nm thick Ta2Pt3Se8 thin-film device exhibited a percent response of 25.9% at room temperature and 32.4% at 100 °C, respectively. In addition, the device showed complete recovery within 14.1 min at room temperature and 3.5 min at 100 °C, respectively.

Multifunctional Cerium Oxide Nanozyme for Synergistic Dry Eye Disease Therapy.

Dry eye disease (DED) is a chronic multifactorial ocular surface disease mainly caused by the instability of tear film, characterized by a series of ocular discomforts and even visual disorders. Oxidative stress has been recognized as an upstream factor in DED development. Diquafosol sodium (DQS) is an agonist of the P2Y2 receptor to restore the integrity/stability of the tear film. With the ability to alternate between Ce3+ and Ce4+, cerium oxide nanozymes could scavenge overexpressed reactive oxygen species (ROS). Hence, a DQS-loaded cerium oxide nanozyme was designed to boost the synergistic treatment of DED. Cerium oxide with branched polyethylenimine-graft-poly(ethylene glycol) as nucleating agent and dispersant was fabricated followed with DQS immobilization via a dynamic phenylborate ester bond, obtaining the DQS-loaded cerium oxide nanozyme (defined as Ce@PBD). Because of the ability to mimic the cascade processes of superoxide dismutase and catalase, Ce@PBD could scavenge excessive accumulated ROS, showing strong antioxidant and anti-inflammatory properties. Meanwhile, the P2Y2 receptors in the conjunctival cells could be stimulated by DQS in Ce@PBD, which can relieve the incompleteness and instability of the tear film. The animal experiments demonstrated that Ce@PBD significantly restored the defect of the corneal epithelium and increased the number of goblet cells, with the promotion of tear secretion, which was the best among commercial DQS ophthalmic solutions.

The Critical Role of Ca2+ in Improving the Transparency and Strength of High-Filler-Content Nanocellulose/Montmorillonite Nanocomposite Films.

Strong and transparent nanocellulose/montmorillonite (MMT) nanocomposite films with high filler content (≥50 wt %) are emerging as versatile materials for advanced applications due to their excellent optical, barrier, mechanical, and thermal properties, and environmental friendliness. Nonetheless, these films undergo a notable decline in optical and mechanical properties at high MMT loadings. This study first demonstrates that calcium-ion-induced tactoids are the key factor causing disordered structures in nanocomposite films, leading to the degradation of optical and mechanical properties. We then address this issue by employing a Ca2+ removal strategy─dialysis. Through removing 43% of free Ca2+, simultaneous improvements in both properties are observed. For example, in a nanocomposite film with 70 wt % MMT, light transmittance increases from 75.9 to 91.6%, and the tensile strength rises from 100.4 to 139.4 MPa. This work offers insights into developing strong and transparent nanocomposite films with high MMT contents.

Improved Reversibility of Thin-Film Solid Oxide Cells at 500 °C by Tailoring Sputtering Processes for Depositing Yttria-Stabilized Zirconia Electrolyte.

The present study investigates the impact of sputtering configurations on the microstructure and crystallinity of thin-film yttria-stabilized zirconia electrolytes for anodized aluminum oxide-supported all-sputtered thin-film reversible solid oxide cells. Employing various sputtering parameters, such as target-substrate distance and substrate rotation speed, the present study reveals distinct surface characteristics and crystalline structures of thin-film yttria-stabilized zirconia. The microstructure analysis includes scanning electron microscopy and atomic force microscopy examinations, uncovering the influence of the process parameters on the surface morphology, roughness, and grain size. X-ray diffraction data illustrate the texture preferences and crystallite characteristics. The electrochemical characterization of the reversible solid oxide cells demonstrates that the optimized sputtering configuration significantly outperforms the others in both SOFC and SOEC modes, showing exceptional current densities of 964 mA/cm2 at 1.3 V in electrolysis mode at 500 °C. Electrochemical impedance spectroscopy further reveals improved charge transfer reactions at the interface of the electrolyte. The enhanced electrochemical performance is attributed to the unique microstructure and crystallinity of the thin film of yttria-stabilized zirconia. The record-breaking electrolysis performance of this work at 500 °C underscores the potential of tailored sputtering parameters in optimizing the reversible solid oxide cell performance.

Efficient enrichment of free target sequences in an integrated microfluidic device for point-of-care detection systems.

Nucleic acid biomarker detection has great importance in the diagnosis of disease, the monitoring of disease progression and the classification of patients according to treatment decision making. Nucleic acid biomarkers found in the blood of patients have generated a lot of interest due to the possibility of being detected non-invasively which makes them ideal for monitoring and screening tests and particularly amenable to point-of-care (POC) or self-testing. A major challenge to POC molecular diagnostics is the need to enrich the target to optimise detection. In this work, we describe a microfabricated device for the enrichment of short dsDNA target sequences, which is especially valuable for potential detection methods, as it improves the probability of effectively detecting the target in downstream analyses. The device integrated a heating element and a temperature sensor with a microfluidic chamber to carry out the denaturation of the dsDNA combined with blocking-probes to enrich the target. This procedure was validated by fluorescence resonance energy transfer (FRET) technique, labelling DNA with a fluorophore and a quencher. As proof of concept, a 23-mer long dsDNA sequence corresponding to the L858R mutation of the EGFR gene was used. The qualitative results obtained determined that the most optimal blocking rate was obtained with the incorporation of 11/12-mer blocking-probes at a total concentration of 6 µM. This device is a powerful DNA preparation tool, which is an indispensable initial step for subsequent detection of sequences via nucleic acid hybridisation methods.

Effect of camellia oil body-based oleogels on the film-forming properties of soy protein isolate.

Soybean protein isolate (SPI) was frequently used to make edible films due to its highly degradability and excellent film forming ability. However, the limited barrier properties and low tensile strength of SPI films prevent their application in food packaging. In this study, the SPI film was modified by blending camellia oil body-based oleogel (COBO). COBO improved the mechanical properties of SPI film and increased its light-blocking, water insolubility and barrier properties. Micrograph, particle size distribution, protein conformation and crystalline structure analysis illustrated that camellia saponin in COBO formed hydrogen bonds with SPI, significantly reduced the particle size of the film-forming emulsion, and enhanced the order and uniformity of composite films structure, thus improved the overall performance of the SPI films. The SPI-COBO film packing delayed the weight loss, total soluble solids content increase, and the decrease in hardness of stored strawberries. This study puts forwards a new approach for SPI film modification by blending natural emulsified lipids, contributing to the development of sustainable packaging alternatives.

Design and Realization of Visual and Contact-Type Fast Charging Power Source.

Charging power supplies with both fast and visualization functions have a wide range of applications in the information and new energy industries. In this paper, the visualized and contact-type fast charging power supply based on WO3 film and Zn sheet is presented, and the prototype devices are fabricated. Different with the charging method of conventional batteries, charging is achieved by a Zn sheet contacting with a WO3 film moistened with water, resulting in a rapid discoloration of WO3. Theoretical investigation indicates that the interaction between Zn sheet and water molecules is the primary cause of the color change in the WO3 film. The WO3 film completes the colouring state within 10 s in the presence of Zn sheet and water, and the open-circuit voltage of the device is 0.7 V, which can be used to drive various electronics by series-parallel connection. This research introduces a novel method to induce colouring of WO3 films and proposes a fast charging mode different from traditional power sources. It provides valuable insights for the future development of fast charging in the field of electrical energy.

Laser-assembled conductive 3D nanozyme film-based nitrocellulose sensor for real-time detection of H2O2 released from cancer cells.

In this work, a nanostructured conductive film possessing nanozyme features was straightforwardly produced via laser-assembling and integrated into complete nitrocellulose sensors; the cellulosic substrate allows to host live cells, while the nanostructured film nanozyme activity ensures the enzyme-free real-time detection of hydrogen peroxide (H2O2) released by the sames. In detail, a highly exfoliated reduced graphene oxide 3D film decorated with naked platinum nanocubes was produced using a CO2-laser plotter via the simultaneous reduction and patterning of graphene oxide and platinum cations; the nanostructured film was integrated into a nitrocellulose substrate and the complete sensor was manufactured using an affordable semi-automatic printing approach. The linear range for the direct H2O2 determination was 0.5-80 µM (R2 = 0.9943), with a limit of detection of 0.2 µM. Live cell measurements were achieved by placing the sensor in the culture medium, ensuring their adhesion on the sensors' surface; two cell lines were used as non-tumorigenic (Vero cells) and tumorigenic (SKBR3 cells) models, respectively. Real-time detection of H2O2 released by cells upon stimulation with phorbol ester was carried out; the nitrocellulose sensor returned on-site and real-time quantitative information on the H2O2 released proving useful sensitivity and selectivity, allowing to distinguish tumorigenic cells. The proposed strategy allows low-cost in-series semi-automatic production of paper-based point-of-care devices using simple benchtop instrumentation, paving the way for the easy and affordable monitoring of the cytopathology state of cancer cells.

Investigation of film Physical properties under various starch thermal treatments with emphasis on Retrogradation effects.

This study investigated the changes in the physical properties of cornstarch-based films as they were retrogradely aged at different temperatures. Using a casting method, the films were fabricated, and their effects on the mechanical properties, thermal stability, barrier properties, and essential properties were analyzed. With prolonged aging and retrogradation periods, reductions in film thickness, solubility, water content, and water vapor permeability of 5.35%, 9.92%, 29.61%, and 20.94%, respectively, were observed. In addition, the surface roughness decreased by 44.46% for Rq (root-mean-square roughness) and 45.61% for Ra (arithmetic average roughness), while the elongation at break decreased by 72.64%. Conversely, the tensile strength, maximum degradation rate, and maximum degradation temperature increased by 116.98%, 99.5%, and 3.21%, respectively. These results provide a fundamental understanding of the changes that occur in the properties of cornstarch-based films during aging and retrogradation.

Dosimetric evaluation of a novel modular cell irradiation platform for multi-modality in vitro studies including high dose rate brachytherapy.

PURPOSE: High dose-rate (HDR) brachytherapy is integral for the treatment of numerous cancers. Preclinical studies involving HDR brachytherapy are limited. We aimed to describe a novel platform allowing multi-modality studies with clinical HDR brachytherapy and external beam irradiators, establish baseline dosimetry standard of a preclinical orthovoltage irradiator, to determine accurate dosimetric methods. METHODS: A dosimetric assessment of a commercial preclinical irradiator was performed establishing the baseline dosimetry goals for clinical irradiators. A 3D printed platform was then constructed with 14 brachytherapy channels at 1cm spacing to accommodate a standard tissue culture plate at a source-to-cell distance (SCD) of 1 cm or 0.4 cm. 4-Gy CT-based treatment plans were created in clinical treatment planning software and delivered to 96-well tissue culture plates using an Ir192 source or a clinical linear accelerator. Standard calculation models for HDR brachytherapy and external beam were compared to corresponding deterministic model-based dose calculation algorithms (MBDCAs). Agreement between predicted and measured dose was assessed with 2D-gamma passing rates to determine the best planning methodology. RESULTS: Mean (±standard deviation) and median dose measured across the plate for the preclinical irradiator was 423.7 ± 8.5 cGy and 430.0 cGy. Mean percentage differences between standard and MBDCA dose calculations were 9.4% (HDR, 1 cm SCD), 0.43% (HDR, 0.4 cm SCD), and 2.4% (EBRT). Predicted and measured dose agreement was highest for MBDCAs for all modalities. CONCLUSION: A 3D-printed tissue culture platform can be used for multi-modality irradiation studies with great accuracy. This tool will facilitate preclinical studies to reveal biologic differences between clinically relevant radiation modalities.

Unfolding the Challenges To Prepare Single Crystalline Complex Oxide Membranes by Solution Processing.

The ability to prepare single crystalline complex oxide freestanding membranes has opened a new playground to access new phases and functionalities not available when they are epitaxially bound to the substrates. The water-soluble Sr3Al2O6 (SAO) sacrificial layer approach has proven to be one of the most promising pathways to prepare a wide variety of single crystalline complex oxide membranes, typically by high vacuum deposition techniques. Here, we present solution processing, also named chemical solution deposition (CSD), as a cost-effective alternative deposition technique to prepare freestanding membranes identifying the main processing challenges and how to overcome them. In particular, we compare three different strategies based on interface and cation engineering to prepare CSD (00l)-oriented BiFeO3 (BFO) membranes. First, BFO is deposited directly on SAO but forms a nanocomposite of Sr-Al-O rich nanoparticles embedded in an epitaxial BFO matrix because the Sr-O bonds react with the solvents of the BFO precursor solution. Second, the incorporation of a pulsed laser deposited La0.7Sr0.3MnO3 (LSMO) buffer layer on SAO prior to the BFO deposition prevents the massive interface reaction and subsequent formation of a nanocomposite but migration of cations from the upper layers to SAO occurs, making the sacrificial layer insoluble in water and withholding the membrane release. Finally, in the third scenario, a combination of LSMO with a more robust sacrificial layer composition, SrCa2Al2O6 (SC2AO), offers an ideal building block to obtain (001)-oriented BFO/LSMO bilayer membranes with a high-quality interface that can be successfully transferred to both flexible and rigid host substrates. Ferroelectric fingerprints are identified in the BFO film prior and after membrane release. These results show the feasibility to use CSD as alternative deposition technique to prepare single crystalline complex oxide membranes widening the range of available phases and functionalities for next-generation electronic devices.

Eco-Friendly Biomemristive Nonvolatile Memory: Harnessing Organic Waste for Sustainable Technology.

Organic material-based bioelectronic nonvolatile memory devices have recently received a lot of attention due to their environmental compatibility, simple fabrication recipe, preferred scalability, low cost, low power consumption, and numerous additional advantages. Resistive random-access memory (RRAM) devices work on the principle of resistive switching, which has the potential for applications in memory storage and neuromorphic computing. Here, natural organically grown orange peel was used to extract biocompatible pectin to design a resistive switching-based memory device of the structure Ag/Pectin/Indium tin oxide (ITO), and the behavior was studied between a temperature range of 10K and 300K. The microscopic characterization revealed the texture of the surface and thickness of the layers. The memristive current-voltage characteristics performed over 1000 consecutive cycles of repeated switching revealed sustainable bipolar resistive switching behavior with a high ON/OFF ratio. The underlying principle of Resistive Switching behavior is based on the formation of conductive filaments between the electrodes, which is explained in this work. Further, we have also designed a 2 × 2 crossbar array of RRAM devices to demonstrate various logic circuit operations useful for neuromorphic computing. The robust switching characteristics suggest possible uses of such devices for the design of ecofriendly bioelectronic memory applications and in-memory computing.

FEATURES OF MAGNETIC STRUCTURES IN PERFORATED FILMS DUE TO THE FINITE THICKNESS OF THE SAMPLE.

The paper examines ferromagnetic films with strong uniaxial anisotropy of the "easy plane" type, in which vortex-like inhomogeneities can arise in the presence of artificially created perforations. A universal approach has been developed that makes it possible to reduce the problem of calculating demagnetizing fields in a film of arbitrary thickness to the simplest case, when the film thickness is large. It has been shown that the influence of demagnetizing fields causes the magnetization vector to necessarily move out of the sample plane, and the spatial distribution of magnetization corresponding to this effect has been studied. It has been revealed that the contribution of demagnetizing fields to the total energy of the magnet changes slightly during the transition from a homogeneous structure to an inhomogeneous one. .

Investigating the physicochemical, antimicrobial and antioxidant properties of chitosan film containing zero-valent iron nanoparticles and oregano essence.

The problems caused by the pollution of the environment by petroleum polymers in recent years have caused researchers to think of replacing petroleum polymers with biodegradable and natural polymers. The aim of this research was to produce composite film of chitosan (Chit)/zero-valent iron (Fe) nanoparticles/oregano essence (Ess) (Chit/Fe/Ess). Central composite design was used to study physical, morphological, antioxidant and antimicrobial properties of films. The results showed that with the increase of iron nanoparticles and oregano essence, the thickness of the film increased. The moisture, solubility and water vapor permeability of the film decreased with the increase of iron nanoparticles and oregano essence. The results of the mechanical test showed that with the increase of iron nanoparticles and oregano essence, the tensile strength and elongation at break point decreased. Iron nanoparticles and oregano essence increased significantly the antioxidant activity of the film. The results of the antimicrobial activity of the prepared films show that the addition of iron nanoparticles and oregano essence enhanced the antimicrobial activity of the film against Escherichia coli and Staphylococcus aureus. X-ray diffraction analysis showed that iron nanoparticles were physically combined with chitosan polymer. Fourier transform infrared (FTIR) results confirmed the physical presence of iron nanoparticles and oregano essence in the polymer matrix. The results of scanning electron microscopy (SEM) showed that the surface of nanocomposite films is more heterogeneous than chitosan. Iron nanoparticles and oregano essence could delay the thermal decomposition of chitosan and increase the thermal stability of chitosan film.