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Polylactic acid (PLA)-curcumin (CCM) composites, incorporating various contents of surface-functionalized dual-metal-doped copper oxide (SF-M-CuO), were prepared by the solution casting method. Synthesized composite films were evaluated for their antioxidant, biocompatible, photothermal, and antibacterial properties. The 4% CCM exhibits excellent compatibility based on total color difference, antioxidant activity, and controlled curcumin release behavior. In addition, different contents of SF-M-CuO (1-4%) were added to the PLA-4%-CCM polymer matrix. Synthesized composite films were characterized through functional, structural, and topographical analyses. FTIR and XRD analyses confirmed the successful incorporation of CCM and SF-M-CuO into the PLA matrix, which enhanced interfacial interactions and increased the crystallinity index by acting as effective nucleating agents. ABTS and DPPH radical scavenging assays revealed dose-dependent antioxidant activity due to the synergistic effects of CCM and SF-M-CuO. Biocompatibility evaluation using RAW 264.7 macrophage cells demonstrated non-toxic responses and enhanced cell proliferation in PLA-4%-CCM composite films containing up to 3%-SF-M-CuO. Among the fabricated films, PLA-4%-CCM-3%-SF-M-CuO exhibited superior photothermal performance and excellent antibacterial activity against Staphylococcus aureus and Escherichia coli, reducing bacterial counts to below the limit of detection. These findings demonstrate the potential of PLA-4%-CCM-3%-SF-M-CuO composite films as sustainable multifunctional materials for food safety and biomedical applications.

The surface composition of a polymer thin film determines the interactions of the film with its environment and equips the film for specific applications, such as a coating, sensor, adhesive, antifoulant, or membrane. We report a rapid and versatile method to tailor the surface properties of polymer films by growing functional top layers on top of inexpensive bottom layers through sequential depositions of different monomer solutions onto a catalyst-coated surface. This method of synthesizing layered films formally expands spin coating ring-opening metathesis polymerization (scROMP), which efficiently integrates polymer film synthesis and deposition into one rapid process, converting the sequential monomers into layered polymer films in under 3 min with less than 600 &#x3bc;L of solvent for a 2.25 cm2 film. The scROMP approach is shown here to synthesize films with polymers of >500 kDa molecular weights and <1.15 dispersities and to effectively stack two or more layers of distinct functionalities that constitute the bulk and surface regions of the film. Thicknesses of the top layers can be dramatically altered by monomer concentration, and the top layer can be extremely thin (within the nanometer range) or as thick as 3&#xd7; the bottom layer (>15 &#x3bc;m) for certain compositions. As potential applications, we demonstrate the syntheses of unique layered films with specialized properties such as omniphobicity, superhydropilicity, and protein resistance.

The present study investigated the effect of liquid smoke (LS) on the physicochemical, structural, barrier, and functional properties of okra mucilage-corn starch (OMCS) films. Formulations containing varying concentrations of LS (0-3%) were prepared using the casting method. The incorporation of LS modified the rheological behavior of the film-forming dispersions, as evidenced by increased apparent viscosity and consistency index. In the films, water solubility increased from 43.6 to 53.2%, contact angle increased from 31.9&#xb0; to 55.6&#xb0;, and opacity increased from 4.73 to 8.83, while water vapor permeability decreased from 1.05 to 0.88 g&#xb7;mm&#xb7;m-2&#xb7;h-1&#xb7;kPa-1, indicating modifications in matrix organization and surface hydrophobicity. Tensile strength increased from 26.3 to 40.5 MPa at 3% LS, accompanied by a slight reduction in elongation, suggesting enhanced structural rigidity. Structural analyses revealed interactions between the LS phenolic compounds and the polysaccharide hydroxyl groups, resulting in a more cohesive polymeric network. LS was the main contributor to the film's antioxidant activity owing to its elevated phenolic content and free radical scavenging capacity. The films also showed substantial degradation under soil burial conditions, with mass loss ranging from 61% to 96%. Overall, LS proved to be an effective functional additive, improving the structural and antioxidant performance of OMCS films and expanding their potential for active food packaging applications.

Cutin, a natural polyester, has attracted attention as a precursor for bio-based materials mimicking plant cuticles, particularly in food packaging. Most studies focus on polycondensation of hydrolyzed cutin fractions or combining cutin hydrolysates with other components; however, cutin precipitation, conditions affecting it, and cutin isolate film properties, without addition of other filmogenic material, remain insufficiently understood. Owing to the pH-dependent solubility of cutin, which progressively decreases as pH is lowered from strongly alkaline to acidic conditions, this study investigates the influence of pH on cutin dispersion formation and characteristics, and evaluates the impact of these dispersion properties on the formation and performance of self-assembled cutin isolate films, with a view to developing films with improved water-barrier and moisture-resistance properties. The influence of three plasticizers, glycerol, propylene glycol, and polyethylene glycol 400, at two concentrations was also evaluated. Results demonstrated that pH is the primary factor influencing cutin isolate dispersion characteristics and film performance, with decreasing pH promoting cutin precipitation and particle aggregation, thereby inducing changes in film structure. The strongest effects were observed for swelling, solubility, and tensile strength, followed by water vapor permeability, elongation at break, and thickness. Plasticizer type mainly affected moisture content and significantly influenced permeability and thickness, while concentration of plasticizer primarily impacted permeability. Interactions between pH and plasticizer significantly influenced most properties. Films prepared from cutin dispersions at pH 6.5 and pH 5 with polyethylene glycol (10%) showed the best balance of mechanical and barrier properties. Additionally, films prepared from the cutin solutions at pH 12 with glycerol (20%) exhibited good mechanical performance and high solubility, suitable for specific applications.

Carbon nanotube (CNT) films prepared via floating catalyst chemical vapor deposition generally suffer from residual iron impurities, structural defects, and weak inter-tube interfaces, which severely limit their mechanical performance. Here, we propose a post-treatment approach, which is dominated by Joule heating, to substantially improve the mechanical properties of CNT films. Acid washing after Joule heating effectively removes iron catalyst and amorphous carbon, increasing the specific strength from 0.64 N/tex to 2.96 N/tex. Pre-stretching induces alignment of the CNTs along the stretching direction, further raising the specific strength to 5.57 N/tex. Subsequent Joule heating not only raises graphitization degree and repairs lattice defects but also transforms the weak van der Waals contacts between tubes into continuous carbon networks, leading to network densification and locking of the aligned structure. The final specific strength reaches 7.04 N/tex and true tensile strength 8.05 GPa, surpassing previous representative carbon materials. The purification mechanism of Joule heating depends on the initial iron content of the film: for high-iron films, iron melts, migrates and forms Fe/Fe3C@C core-shell particles, which can be converted into hollow carbon shells via acid etching; for low-iron films, iron is removed via atomic diffusion and evaporation. This work provides a fast, controllable and synergistic technical route for the preparation of high-performance CNT macrostructures.

This study investigated the rheological, structural, barrier, mechanical, optical, and thermal properties of composite edible films based on citrus pectin and vegetable pur&#xe9;es derived from broccoli, cauliflower, pumpkin, carrot, and their blends. Film-forming formulations were characterized in terms of rheological behavior, thickness, microstructure, gas and water vapor permeability, optical and mechanical properties, water contact angle, and thermal stability. The incorporation of vegetable pur&#xe9;es significantly modified the properties of the pectin-based matrices. All film-forming solutions exhibited non-Newtonian shear-thinning behavior, with flow behavior index values below unity. The addition of vegetable pur&#xe9;es markedly increased viscosity and flow resistance, indicating the formation of more structured systems with stronger intermolecular interactions. Apparent viscosity increased from 0.19 Pa&#xb7;s in the control sample to 1.41 Pa&#xb7;s and 1.19 Pa&#xb7;s in the broccoli (B) and broccoli-cauliflower (B-CF) formulations, respectively, while the consistency coefficient increased from 0.29 to 51.38 Pa&#xb7;sn. Composite films exhibited lower water contents (0.090-0.114 gH2O&#xb7;gd.m.-1) than the control film (0.179 gH2O&#xb7;gd.m.-1) and were thicker (170-282 &#x3bc;m) than the pure pectin film (125 &#x3bc;m). Barrier analysis revealed a reduction in water vapor permeability from 18.99&#xb7;10-10 to 10.74-14.69&#xb7;10-10 g&#xb7;m-1&#xb7;s-1&#xb7;Pa-1 and a decrease in carbon dioxide permeability from 21.95 to 10.47-17.91 GRT. The carrot-containing film exhibited the highest tensile strength (62.17 MPa), whereas the pumpkin-carrot film demonstrated the most favorable combination of barrier and mechanical properties, including the lowest oxygen permeability (6.95 GRT), low water vapor permeability (10.74&#xb7;10-10 g&#xb7;m-1&#xb7;s-1&#xb7;Pa-1), and high tensile strength (51.02 MPa). Thermogravimetric analysis revealed similar three-stage degradation profiles for all samples, while vegetable incorporation modified moisture release and increased residual mass. The obtained results confirmed the research hypothesis that vegetable-processing by-products can serve as valuable structure-forming components of pectin-based composite films and that interactions between vegetable-derived biopolymers and citrus pectin improve the mechanical, barrier, and functional properties of the resulting materials. Among the tested formulations, the pumpkin-carrot film demonstrated the greatest potential for further development as a biodegradable packaging material. The utilization of vegetable by-products in pectin-based films represents a sustainable approach supporting circular economy principles and the development of environmentally friendly packaging systems.

The high-voltage spinel LiNi0.5Mn1.5O4 (LNMO) is a promising cobalt-free cathode material for lithium-ion batteries, yet its integration as a binder-free thin film on metallic current collectors via simple solution routes remains underexplored. Here, LNMO films were synthesized on 304 stainless steel (SS304) by metal-organic decomposition (MOD) from metal-acetate precursors in ethanol, followed by spin-coating and annealing at 500, 600, and 700 &#xb0;C under flowing O2. The films were characterized by XRD, FESEM-FIB cross-sectioning, EDS, and XPS, and tested as binder-free cathodes by cyclic voltammetry and galvanostatic charge/discharge. All samples are dense, approximately 1.9 &#x3bc;m thick, and crystallize in the disordered spinel phase. The LNMO crystallite size increases from 21.9 to 43.8 nm between 500 and 700 &#xb0;C, while the grain size also shows a temperature dependence, increasing the average size from 25 up to 56 nm in diameter. XPS confirms Mn4+ as the dominant manganese surface species (45-49%) across all samples. The films deliver reversible discharge capacities of 92, 92, and 70 mAh g-1 at 0.1 C for LNMO500, LNMO600, and LNMO700, respectively, with well-defined Ni2+/Ni3+ and Ni3+/Ni4+ redox peaks at 4.7 and 4.8 V. DFT calculations independently predict a voltage plateau at &#x223c;4.7 V for 0.2&#x2264;x&#x2264;1, in agreement with the experimental profiles. These findings establish MOD as a viable, vacuum-free route to the synthesis of nanostructured LNMO cathodes.

Polymer-stabilized liquid crystal (PSLC) films are promising for smart window applications because of their transparent-to-scattering switching behavior. However, conventional acrylate-based PSLC films often suffer from poor mechanical robustness and weak interfacial adhesion, limiting their use in flexible devices. Herein, epoxy-based PSLC films have been prepared through radical-promoted cationic photopolymerization using a difunctional epoxy monomer, E6M, and a series of liquid-crystalline monoepoxy monomers, E-nOCB. The effects of alkyl chain parity, chain length, and E6M/E-10OCB ratio on polymer morphology, electro-optical behavior, and peel strength were systematically investigated. Even-numbered E-nOCB monomers favored the formation of regular columnar polymer structures and improved optical contrast, whereas odd-numbered monomers produced more disordered networks with higher peel strength. Among them, the sample prepared with E-10OCB showed a better balance between electro-optical performance and mechanical adhesion. At a fixed total polymer content of 15 wt%, optimizing the E6M/E-10OCB ratio enabled the sample doped with E-10OCB to achieve the highest contrast ratio of 160.91 while increasing the peel strength from 47.28 to 55.69 kPa compared with the sample without E-10nOCB. These results demonstrate that regulating monoepoxy/diepoxy composition and alkyl chain structure is an effective strategy for improving the overall performance of epoxy-based PSLC films for smart windows.

In this study, the valorization of poly(lactic acid) (PLA) waste as well as rice husk into sustainable materials was explored. To simulate the industrial valorization of defective PLA parts, scraps and burrs, PLA was reprocessed (rPLA) by melt extrusion and further plasticized with 15 wt.% of acetyl tributyl citrate (ATBC) and reinforced with rice husk (RH) or rice husk biochar (RHB) in 1 or 3 wt.%. The melt flow index was determined to assess the effect of reprocessing and the addition of RH or RHB on the material degradation. The obtained films were characterized in terms of their structural, mechanical, and thermal behavior. The water-related behavior of the materials was evaluated by measuring the static water contact angle and the water vapor transmission rate (WVTR). Compostability was proposed as an end-of-life option, therefore disintegration under composting conditions was assessed. Reprocessing increased the MFI and slightly reduced the strength and the modulus, consistent with chain scission. ATBC facilitated the processability, improved the particles' dispersion and provided ductility to the final materials. RH and RHB acted mainly as nucleating agents and strongly modified the surface wettability. A low RHB loading improved the WVTR, whereas a higher filler content and ATBC generally increased the WVTR. All the films were completely disintegrated within 18 to 21 days. These results show practical valorization routes to obtain rPLA films with tunable properties and to preserve the inherent composting disintegration of PLA.

This study investigates the fabrication of eco-friendly composite films based on guar gum (GG) reinforced with untreated rice husk (URH) powder (5-30 wt%) via a thermocompression process. To the best of our knowledge, this is one of the first demonstrations of directly utilizing untreated rice husk as a multifunctional reinforcing filler in GG-based bioplastics without any chemical or surface modification, thereby eliminating energy-intensive pretreatment steps. Particle dispersion and interfacial adhesion were optimal up to 10 wt% loading, above which agglomeration occurred. The incorporation of URH enhanced the thermal stability of the matrix. Mechanical performance peaked at 10 wt% URH, exhibiting a 90% increase in tensile strength, a 32% increase in elongation at break, and a 246% improvement in toughness compared to the neat GG film. Furthermore, URH addition reduced moisture content and water vapor permeability while increasing the water contact angle. Although film opacity increased, the results demonstrate that URH acts as an effective multifunctional filler. These GG/URH composite films exhibit strong potential for scalable industrial applications in eco-friendly food packaging, including disposable pouches and trays, offering a sustainable alternative to petroleum-based plastic materials.

A KGM/CMC/PVA film loaded with a hydroxypropy-&#x3b2;-cyclodextrin/hesperetin (HP-&#x3b2;-CD/HES) inclusion complex was developed for strawberry preservation. The inclusion complex showed an encapsulation efficiency of 70.41 &#xb1; 4.01%. Loading the inclusion complex enhanced the barrier and bioactive properties of the films. At the better loading level (KCP-HH3, 1.5%), the film provided nearly complete UV shielding at 200-350 nm and showed a transmittance of approximately 21% at 800 nm. Relative to KCP, KCP-HH3 exhibited lower water vapor permeability (0.69 &#xb1; 0.06 g&#xb7;mm/(m2&#xb7;h&#xb7;kPa)) and oxygen permeability (0.066 &#xb1; 0.006 g&#xb7;mm/(m2&#xb7;h&#xb7;kPa)). The cumulative HES release from KCP-HH3 reached 82.43 &#xb1; 2.19% after 7 days at 98% relative humidity. KCP-HH3 scavenged 78.19 &#xb1; 3.71% of DPPH radicals and 88.89 &#xb1; 4.30% of ABTS radicals. It also inhibited Escherichia coli (91.18 &#xb1; 2.99%), Staphylococcus aureus (79.21 &#xb1; 3.45%), and Aspergillus niger (92.85 &#xb1; 2.75%). This highest-loading formulation delivered the best overall strawberry-preservation performance. After 12 days of storage, strawberries packaged with KCP-HH3 showed higher firmness (0.89 &#xb1; 0.04 N) and total soluble solids (7.96 &#xb1; 0.21%), as well as lower weight loss (14.30 &#xb1; 0.40%), than the polyethylene control, which showed a firmness of 0.42 &#xb1; 0.05 N, total soluble solids of 6.22 &#xb1; 0.20%, and weight loss of 16.36 &#xb1; 0.66%. These results support the potential of HP-&#x3b2;-CD/HES-loaded KCP films as biodegradable active packaging for fruit preservation.

Copper oxide (CuO) has emerged as a promising p-type semiconductor for a wide range of applications, including gas sensing and photoelectric devices. This is due to its narrow band gap, high chemical stability and low cost. In recent years, increasing attention has been paid to the development of high-quality CuO thin films with precisely controlled structural and electronic properties. Among various fabrication techniques, atomic layer deposition (ALD) provides unique advantages like excellent thickness control, conformality and tunability of film composition at the atomic scale. This review provides a comprehensive overview of CuO thin films with a particular focus on ALD-based fabrication approaches. First, conventional deposition methods are briefly discussed. Next, the fundamentals of ALD processes for CuO growth are presented including precursor chemistry, reaction mechanisms and the influence of key process parameters. Special attention is given to the correlation between deposition conditions and the resulting structural, optical and electrical properties of the films. Subsequently, the impact of these properties on device performance is analyzed in the context of gas sensing and photoelectric applications. Finally, current challenges and future perspectives are outlined, emphasizing the need for improved control over phase composition, defect engineering, and integration with nanostructured systems.

With the continuous evolution of the food industry, extending the shelf life of products while maintaining quality and safety has become a major challenge, alongside growing environmental concerns related to conventional plastic packaging. This study aims to provide an overview of recent advances in active biodegradable films as sustainable alternatives for food applications. A comprehensive review of the relevant literature was conducted, including bibliometric analysis to identify key research directions, emerging trends, and technological developments in the field. Our findings highlight the growing interest in biodegradable polymers incorporated with active compounds, such as antioxidants and antimicrobial agents, which contribute to delaying degradation processes and preserving food freshness. Additionally, the analysis emphasizes the mechanisms of action of these active substances and the factors influencing the biodegradability of packaging materials. The results also reveal a shift toward environmentally friendly solutions driven by the need to reduce plastic waste and improve sustainability. In conclusion, active biodegradable films represent a promising approach to enhancing food preservation while minimizing environmental impact, although further research is needed to optimize material performance, scalability, and industrial applicability.

(1) Background: The development of biodegradable polymers with enhanced functionality is critical for advancing sustainable packaging technologies. This study addresses the challenge of simultaneously improving the structural rigidity and functional performance of poly(lactic acid) (PLA) materials. (2) Methods: Cellulose nanowhisker (CNW) and TiO2 nanoparticle (Nano-TiO2) reinforced PLA porous composite films were fabricated via a nanoparticle-assisted breath figure method. The effects of these hybrid nanoparticles on the morphology, thermal stability, and structure of the resulting composites were systematically investigated. (3) Results: The incorporation of CNWs and Nano-TiO2 played a dual role: they acted as Pickering-like stabilizers at the water/polymer interface, preventing droplet coalescence and facilitating the formation of a well-defined honeycomb-like porous structure. They also significantly enhanced the relative crystallinity of the PLA matrix from 20.26% to 36.31%, owing to the heterogeneous nucleation effect. Consequently, the mechanical properties were significantly enhanced, with the maximum tensile strength and Young's modulus increasing by 123.3% and 21.9%, respectively. Furthermore, the composite films exhibited excellent UV-shielding performance, achieving an SR UV-B of 97.6%. (4) Conclusions: The synergistic reinforcement of CNWs and Nano-TiO2 effectively endows PLA composites with superior mechanical properties and functional protection. These findings establish the CNWs-Nano-TiO2/PLA composite film as a promising candidate for high-performance smart packaging applications.

Copper(I) halides are promising for X-ray scintillation owing to high luminescence and solution processability, but their poor stability limits practical use. Here we report a zero-dimensional coordinative cluster, (DPPM)2Cu4I4 (DPPM = bis (diphenylphosphino) methane), prepared by a simple anti-solvent crystallization that emits bright orange light with an absolute photoluminescence quantum yield of 91.11%. Spectroscopic analysis (long lifetime, large Huang-Rhys factor) indicates self-trapped-exciton dominated radiative recombination. The cluster shows outstanding thermal (stable to &#x2248;362 &#xb0;C), solvent (stable after 30 d in H2O, EA, EtOH, IPA) and air stability (>60 d), addressing common durability issues of copper(I) halides. Using an in situ growth method, microcrystals of (DPPM)2Cu4I4 were uniformly incorporated into a thermoplastic polyurethane (TPU) matrix to form flexible scintillator films. The composite exhibits a high light yield of 17,064 photons MeV-1 and a spatial resolution of 14 lp mm-1, highlighting its great potential for practical X-ray imaging applications.

This study focuses on sustainable atmospheric water harvesting (AWH) using film-containing green nanomaterials. Particular emphasis is given to chitosan as a sustainable biopolymer matrix due to its intrinsic hydrophilicity, biodegradability, film-forming ability and abundance of amino and hydroxyl functional groups that favor water adsorption and nanoparticle interaction. ZnO, SiO2 and Fe-Zn-SiO2 nanoparticles with abundant hydroxyl groups were synthesized from plant-based materials such as biomass from peanut and banana wastes, as well as plant extracts. Nanocomposite membranes containing nanoparticles with a high specific surface area and moisture-sensitive behavior were successfully developed. Results showed that bilayer films outperformed monolayer systems in water harvesting performance. In particular, the bilayer film composed of Chitosan/G-ZnO (10 wt.%) on the top layer and Chitosan/G-SiO2 (10 wt.%) in the bottom layer displayed outstanding hydrophilic properties with water contact angles reduced to 42-43&#xb0;. The material demonstrated an equilibrium adsorption capacity for water at 0.90 g/g and a passive yield of 1.5-2.2 mL/g per day. The improved adsorption behavior was attributed to the synergistic effect between the hydroxyl-rich oxide nanoparticles, the intrinsic water affinity of chitosan, and the layered porous structure. Moreover, the samples showed good thermal and mechanical stability and retained their structure after several uses. These findings highlight the potential of chitosan-centered green nanocomposites as sustainable materials for passive AWH applications.

Gold nanoparticles (AuNPs) have shown considerable promise in catalysis and optoelectronics; however, their inherent tendency to aggregate and their limited processability hinder practical applications. Herein, we present a systematic ligand-engineering strategy for tailoring the hierarchical assembly of AuNPs into functional hybrid films, employing four structurally related 1,2,4-triazole multidentate molecules of increasing coordination complexity under a unified solution compounding-vacuum filtration-thermal curing route. The results demonstrate that the type, number, and interplay of coordinating functional groups on the triazole scaffold govern the assembly architecture and interparticle plasmonic coupling, enabling a ligand-programmed color-tunable effect from wine-red through purple and blue to gray-brown. Among the series, the C2H6N6S -modified film-bearing thiol (-SH), amine (-NH2), and hydrazide (-NHNH2) groups on a single molecular scaffold-delivers the highest catalytic activity for 2-nitrophenol reduction, achieving complete conversion within 14&#xa0;min and maintaining over 95% conversion after nine consecutive cycles. Combined XPS, XRD, and SEM analyses attribute this performance to the multidentate coordination of C2H6N6S, which simultaneously enables dense particle packing, favorable electronic modulation of the Au surface, and robust structural stability. This work establishes a structure-property framework linking ligand multifunctionality to thin-film performance, and provides a rational design principle for engineering AuNP-based hybrid materials with tailored.

In the original publication [...].

Doping two-dimensional (2D) semiconductors without direct chemical or structural modification of the channel remains a central challenge for device integration. Here we demonstrate an electrostatic doping strategy on monolayer MoS2 based on embedding fixed charge in engineered dielectric stacks, enabling carrier modulation in the absence of volatile external bias. By comparing different dielectric architectures, we show that effective electrostatic doping is governed by the defect landscape of the capping dielectrics and their interface with the 2D channel. A self-consistent electrostatic model reveals that interface states control the partitioning of the dielectric embedded charge between carriers trapped in defects or free for conduction in the channel, posing limits to the effectiveness of electrostatic coupling. This work establishes electrostatic doping as a viable strategy for carrier modulation in 2D semiconductors and identifies dielectric defect engineering as central to its implementation.