Properties Of Composite Films Research Articles

Utilization of Pickering emulsion stabilized by chitin nanofibers for improving water and oxygen resistance of gelatin films

The hydrophilicity of gelatin films obviously limits their application. In this work, novel protonated chitin nanofiber was prepared with green methods, surficial deacetylation combined with acidic and mechanical treatment. Composite films with excellent water and oxygen barrier properties were successfully prepared by blending O/W Pickering emulsions stabilized by chitin nanofibers with gelatin substrates. The films were characterized by Fourier-transform infrared, X-ray diffraction, mechanical properties, water and oxygen permeability, moisture content, water solubility, water contact angle and optical properties. The results demonstrated that the amino groups of chitin nanofibers bound to the carboxyl groups of gelatin via electrostatic interactions, which contributing to the excellent mechanical and barrier properties of composite films. The elongation at break of composite film (the concentration of chitin nanofiber was 0.2 wt%) was 2.66 times of gelatin film. And the water vapor and oxygen permeability of composite films lowered to 65.9 % and 52.9 %, respectively. The introduction of O/W Pickering emulsion significantly enhanced the hydrophobicity of gelatin-based film and the chitin nanofibers played a positive role in stabilizing the gelatin chains to a certain extent. This study expands the application fields of gelatin-based films and provides valuable technical route for the preparation of barrier films.

Self-Charging Power System Empowered by Bismuth Halide Perovskite-Based Hybrid Nanogenerator and Lithium-ion Battery.

Halide perovskite, renowned for its multifunctional properties, shows considerable promise for realizing self-charging power systems. In this study, a lead-free methylammonium bismuth iodide (MA3Bi2I9) perovskite is used to create a self-charging power unit (SPU). This involves constructing a hybrid piezoelectric-triboelectric nanogenerator (Hybrid-TENG) and utilizing MA3Bi2I9 for energy storage as an anode in a lithium-ion battery (LIB). Initially, MA3Bi2I9 nanorods are synthesized and composited with a polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene polymer. The dielectric and mechanical properties of composite films having perovskite loading content are investigated. The optimized Hybrid-TENG exhibits superior performance, generating a voltage of 537V, current density of 13.2µAcm- 2, and maximum power density of 3.04mWcm-2, which can be attributed to the high piezoelectric coefficient of MA3Bi2I9 nanorods (≈20.6pmV-1). A MA3Bi2I9 thin film, serving as an electrode in LIB, demonstrates a high specific capacity of 2378.9mAhcm-3 (578.8mAhg-1) with a capacity retention of ≈87.5% over 100 cycles, underscoring its stable performance. Furthermore, a Hybrid-TENG is employed to charge the MA3Bi2I9-based LIB, thus realizing an SPU for driving portable electronics. This study highlights the promising potential of perovskites for developing efficient nanogenerators and LIBs, paving the way for sustainable energy solutions in small-scale electronics.

Microwave Properties of Composite Films Based on Polyvinyl Chloride and Brominated Activated Carbon

AbstractBrominated activated carbon (AC/Br2) powder was used as a filler in poly(vinyl chloride) (PVC) to prepare PVC‐based composite films by hot pressing. The AC/Br2 filler was obtained by liquid phase bromination and contained both oxygen and bromine. In comparison with the unmodified AC, the AC/Br2 was subjected to thermogravimetric analysis in air and argon and temperature‐programmed desorption mass spectrometry in vacuum, which identified carbon‐oxygen and bromine groups and showed the comparable thermal stability of AC/Br2 and AC. XPS shows the predominance of phenolic groups among the carbon‐oxygen groups. Scanning electron microscopy and transmission electron microscopy showed preserved morphology and microstructure, while N2 adsorption showed a microporosity decrease after bromination. FTIR analysis suggested non‐chemical interactions between PVC and AC/Br2. As the AC/Br2 content in the PVC‐based composite films increases from 0.2 to 30 wt %, the electromagnetic radiation (EMR) reflection at Ka‐band microwave frequencies increases. To reduce the EMR reflection, the proposed composite films should contain a maximum of 0.2 wt % AC/Br2. The results indicate that the microwave properties of PVC‐based composite films can be tuned by adjusting the AC/Br2 content.

Mechanical and barrier properties of chitosan-based composite film as food packaging: A review

Chitosan can serve as a natural alternative to petroleum-based components in food packaging; however, the mechanical and barrier properties of pure chitosan film possess certain limitations. This paper presents a comprehensive review on the mechanical and barrier properties of composite films formed by combining chitosan-based films with plasticizers, polysaccharides, proteins, and lipids. These composite films often exhibit superior mechanical strength and enhanced barrier performance compared to pure chitosan film, thereby expanding the potential applications of chitosan in food packaging. Chitosan represents an ideal raw material for developing innovative biofilms that can cater to diverse packaging requirements for various food products while offering promising prospects for broad application.

Effect of Poly(propylene carbonate) on Properties of Polylactic Acid-Based Composite Films.

To enrich the properties of polylactic acid (PLA)-based composite films and improve the base degradability, in this study, a certain amount of poly(propylene carbonate) (PPC) was added to PLA-based composite films, and PLA/PPC-based composite films were prepared by melt blending and hot-press molding. The effects of the introduction of PPC on the composite films were analyzed through in-depth studies on mechanical properties, water vapor and oxygen transmission rates, thermal analysis, compost degradability, and bacterial inhibition properties of the composite films. When the introduction ratio coefficient of PPC was 30%, the tensile strength of the composite film increased by 19.68%, the water vapor transmission coefficient decreased by 14.43%, and the oxygen transmission coefficient decreased by 18.31% compared to that of the composite film without PPC, the cold crystallization temperature of the composite film increased gradually from 96.9 °C to 104.8 °C, and PPC improved the crystallization ability of composite film. The degradation rate of the composite film with PPC increased significantly compared to the previous one, and the degradation rate increased with the increase in the PPC content. The degradation rate was 49.85% and 46.22% faster on average than that of the composite film without PPC when the degradation was carried out over 40 and 80 days; the composite film had certain inhibition, and the maximum diameter of the inhibition circle was 2.42 cm. This study provides a strategy for the development of PLA-based biodegradable laminates, which can promote the application of PLA-based laminates in food packaging.

Microstructural evolution during the crystallization process of sol-gel derived PbZrO3 nanocomposite thin films

For the application of dielectric materials in energy storage, nanocomposition is one of the effective methods to improve their electric breakdown field strength. In this study, PbZrO3-Al2O3 nanocomposite films were prepared by combined thermal evaporation deposition and a sol–gel method. By changing the annealing time, the crystallization process of PbZrO3 matrix and the formation mechanism of Al2O3 nanoparticles were studied, and the microstructure evolution process of composite films was elucidated. The results indicate that before the final annealing at 700 ℃, Al atoms have diffused into the amorphous PbZrO3 film, and some fine grains of the perovskite phase have been generated at the bottom of the film. As the annealing time increases, the perovskite grains grow along the out of plane direction of the thin film to form columnar grains, and Al atoms diffuse into the perovskite phase lattice; As the annealing time further increases, Al2O3 nanoparticles began to precipitate at the interlayer interfaces of PbZrO3 coating layers, forming a layered distribution. The changes in electric properties with annealing time also demonstrate the microstructural evolution process of the composite film during annealing. Therefore, controlling annealing time is an effective means to control the microstructure and electric properties of composite films prepared by the new method for the application of energy storage.

Effect of rapid/slow annealing routes on the magnetic and photoelectric properties of BiFeO3/CoFe2O4 multilayer thin films

With the development of electronic information technology, the miniaturization of lightweight devices and their integration have increased the requirements for materials, and two-dimensional composite multiferroic materials have become a major research hotspot in recent years. However, it is difficult for traditional solid multiferroic material to directly switch the magnetic/polarization direction under the action of an applied electric/magnetic field, limiting the improvement of the magnetoelectric coupling coefficient. In this study, a series of BiFeO3 (BFO)/CoFe2O4 (CFO) composite film multiferroic materials were prepared by changing the annealing routes and annealing atmosphere, the microstructure, ferroelectric properties, dielectric properties, photovoltaic properties, magnetic properties, and magnetoelectric coupling properties of composite films were routeatically studied. The results showed that under the slow annealing route, the composite film has obvious ellipsoidal grains with distinct grain boundaries and better crystallinity. Moreover, the performance of the film after annealing in different atmospheres of the slow annealing route was improved compared with that of the rapid annealing route after annealing in different atmospheres. Simultaneously, by changing the annealing atmosphere of the composite film, the film exhibited better magnetic optical properties and coupling properties after annealing in oxygen. In addition, this study showed that the dielectric constant and residual polarization value of the film increase under the action of magnetic field and illumination, and the maximum photomagnetic dielectric response (3.19%) and photomagnetic response (1.58%) are observed in the annealed film under the oxygen atmosphere of the slow annealing regime, indicating that the magnetoelectric coupling effect of the film is improved under the action of applied light.

Characterization of a Clove Essential Oil Slow-Release Microencapsulated Composite Film and Its Preservation Effects on Blueberry.

In order to extend the shelf life of fruits and vegetables, a sodium alginate-sodium carboxymethyl cellulose composite film loaded with poly(vinyl alcohol) microcapsules was prepared in this paper. The optimal film substrate ratios were obtained after the response surface optimization. Poly(vinyl alcohol) microcapsules were prepared, clove essential oil was loaded into them to investigate the effects of microcapsules on the composite film properties, and the microcapsule composite film with the best overall performance was selected to be applied to blueberry preservation. The results showed that the composite film of 0.84% sodium alginate, 0.25% sodium carboxymethyl cellulose, and 0.56% glycerol presented excellent mechanical properties after adding 1.75% microcapsules. It had a good inhibitory effect on Escherichia coli, Staphylococcus aureus, and Penicillium and had a DPPH clearance rate of 83.78%. The low-temperature bonded composite film could slow down the respiration rate of blueberry, inhibit browning and water loss, effectively maintain the quality of blueberry, and have a significant preservation effect on the anthocyanin and soluble solid content of blueberry. The clove essential oil slow-release microencapsulated composite film can be used for blueberry preservation.

Morphological and mechanical properties of chitosan/cellulose nanofibrils/aspirin polymer nanocomposite films

This study examined the mechanical properties of composite films composed of chitosan, cellulose nanofibrils, and aspirin. This biomaterial has promising characteristics and holds potential for various applications. The composite material, which was synthesised using precise fabrication techniques, consists of chitosan as a biocompatible substrate, cellulose nanofibrils for enhancing structural integrity, and aspirin for additional therapeutic benefits. The composite material exhibited increased tensile strength, tensile modulus, and elongation at break. The experimental results demonstrate that the tensile strength and tensile modulus exhibit an upward trend as the loading of cellulose nanofibrils (CNFs) increases. This observation suggests a synergistic improvement in mechanical robustness, which can be attributed to the combined effects of chitosan and CNFs. A reduction in elongation at break was seen as the loading of CNFs increased. The adaptability of the material is further emphasised by its tensile modulus and elongation at break. This study presents opportunities for the development of sustainable packaging materials, as the biodegradable properties of chitosan and cellulose are in line with current environmental priorities. The composite films composed of chitosan, cellulose nanofibrils, and aspirin demonstrate a notable combination of mechanical robustness and therapeutic properties. This research establishes the foundation for future attempts in biomaterial design by introducing a versatile composite that has the potential to significantly influence various sectors, including materials science and healthcare.

Mechanical and gas permeability properties of poly(L‐lactic acid)–based films and their application in fresh produce preservation—Review

AbstractPlastics have remained the best choice for fruit and vegetable packaging due to their exceptional transparency, flexibility, optional good barrier and cost‐effectiveness. However, a large number of plastics end up in the environment after serving their intended purpose and persist there for centuries. Since worldwide attention to environmental issues has become an irreversible historical trend, cost‐effective renewable biodegradable packaging material is highly desirable for the packaging industry to satisfy both industrial demands as well as consumer expectations. Poly (L‐lactic acid) (PLLA), a renewable biodegradable polymer derived from biomass, has been widely studied as a very attractive polymer for food packaging applications. However, its brittle nature and medium CO2/O2 permeability are not friendly for its utilisation in the aspect of fresh agricultural products packaging. In such a context, great efforts have been devoted to improvements in the mechanical and permeability of PLLA to meet the requirements of food packaging. The main purpose of the review is to summarise the mechanical and permeability properties of composite films developed by the incorporation of toughness reinforcing agents into the PLLA matrix. The elongation at break of PLA can be increased up to 250 times by modification, and the CO2 permeability of PLA can be increased by 2–3 times by modification. We also elaborate on studies of the preservation effect of PLLA composite films on fresh fruits and vegetables.

Porous‐structured vermiculite/polybutylene adipate terephthalate composite films: The morphology, mechanical properties, and nonisothermal degradation kinetics

AbstractTo examine the impact of vermiculite (VMT) on the environmental and physical aspects of polybutylene terephthalate (PBAT), the thermal degradation behavior of VMT/polybutylene terephthalate polyadipate (VMT/PBAT) composite films was investigated by using the thermogravimetric analysis (TGA). To ensure precise calculation of the specific activation energy values of VMT/PBAT composite films in thermal degradation performance experiments, the Kissinger method (K‐method) and Flynn–Wall–Ozawa method (FWO method) were utilized. Additionally, the reaction mechanism was analyzed using the Coats–Redfern equation (CR equation). The introduction of VMT into the PBAT co‐polyester structure leads to an increase in the thermal degradation activation energy Ek of composite films.; the apparent activation energies were calculated by the Coats–Redfern method for different reaction mechanisms, and the interfacial diffusion reaction mechanism of the composite film was determined, with a thermal degradation reaction principle properties of g(α) = [1 − (1 − α)]2 and the number of reaction steps of 2.Highlights VMT/PBAT composite films prepared using a simple method. Analyzing nonisothermal degradation kinetics using K‐method and FWO method. Analyzing the degradation mechanisms using the Coats–Redfern equation. Addition of VMT enhances the thermal degradation properties of composite films. Addition of VMT reduces the mechanical properties of the composite film.

PLASMA DISCHARGE IN LIQUID MEDIA UNDER THE EFFECT OF ULTRASOUND FOR THE SYNTHESIS OF FILLERS FOR POLYMER COMPOSITES WITH ENHANCED MECHANICAL STRENGTH AND GAS PERMEABILITY

Zinc oxide nanoparticles were synthesized using a plasma discharge method under the effect of ultrasonic cavitation, and films of a polymer composite material were obtained and studied. Comparatively, the mixture of zinc oxide nanoparticles with planar graphene oxide nanostructures were also used as a filler. Using melt compounding technology, composite materials were obtained in the form of thin films consisting of the copolymer of ethylene and vinyl acetate and nanoparticles of zinc oxide and graphene oxide. The obtained samples of composite materials were examined by X-ray phase analysis, X-ray fluorescence analysis, and scanning electron microscopy. The physical, mechanical, and gas transport properties of composite films made of polymers filled with nanoparticles were studied: permeability measurements were carried out for carbon dioxide and helium gases.

Development of Carbon Nanotubes–Graphene–Polydimethylsiloxane Composite Film with Excellent Electrothermal Performance

Low power density and low heating rate are the key constraints for the development of conductive polymer materials in the field of electric heating. The carbon nanotubes (CNTs)–graphene (GR)–polydimethylsiloxane (PDMS) composite film was prepared by vacuum filtration and spin coating to solve the problem in this study. Moreover, an AC electric field was used to orient the CNTs to enhance the electrothermal performance. The structure and properties of composite films were analyzed. The results show that the composite film with CNT:GR = 2:1 has the lowest permeation threshold, and can heat up within 30 s and stabilize at 260 °C at 10 V. The electric field-oriented CNTs reduced the insulating polymer layer, increasing the heating rate of the composite film by 1.2 times, and increasing the theoretical thermal conductivity. The flexible electrothermal composite film prepared in this study can be used in thermal insulation, deicing, and wearable electronic devices.

Study on the structural and properties of composite films prepared by blending EUL and NBRL

In order to address issues such as poor dimensional stability caused by low modulus and tensile stress of nitrile butadiene rubber latex (NBRL) films, as well as poor wearing comfortability due to its good adhesion to the human skin, and the inability to meet the requirements of medical special occasions due to low tensile and tear strength. A new strategy is proposed to develop the Eucommia ulmoides latex (EUL) by using the emulsion solvent evaporation technique. EUL was then blended into the NBRL, successfully preparing the NBR/EUG composite latex film. As the Eucommia ulmoides gum (EUG) content increased from 0 to 40 %, the crystallinity of the NBR/EUG composite latex film gradually increased from 0 to 10 % or so. The tensile strength increases from 5.17 MPa to 15.94 MPa, the tear strength increases from 22.17 kN/m to 37.79 kN/m, the modulus increases from 6.40 MPa to 24.80 MPa. The very important point is that the elongation at break keep stable with the increase of EUG. On the contrary, the elongation at break will decrease with addition of conventional fillers into the latex, such as silica. These enhance mechanical properties and keep the dimensional stability of the film. Therefore, it can be utilized for the development of latex film products with high modulus and big deformation, such as sky balloon and foam mattress. Additionally, the crystalline nature of EUG effectively reduces the adhesion force on the surface of the composite latex film, thus improving its compatibility with human skins. This meets the requirements of special environments, such as medical gloves. At last, as a kind of biobased latex, it can increase the content of renewable resources and reduce the carbon emission of NBRL.

Eggshell powder as a bio-filler for starch and gelatin: Ternary biodegradable composite films manufactured by extrusion compression molding

Recovery of food waste eggshell powder (ESP) as a bio-filler for biopolymer matrix to develop sustainable composites is an attractive recycling strategy nowadays. Herein, biodegradable composite films based on potato starch/gelatin (PS/G) containing different concentrations (0%–50%, w/w, of the total mass of PS/G) of ESP were manufactured using thermal extrusion followed by compression molding. Interaction and compatibility of film components were evaluated by using Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). Color, opacity, mechanical properties, water vapor and oxygen permeability, and biodegradability of the composite films were also systematically characterized. The existence of hydrogen bonding interactions between the amino groups of organic compounds on ESP surface and the hydroxyl groups of starch and gelatin was confirmed by FTIR, and the ESP particles were uniformly dispersed in the film matrix with good adhesion as observed by SEM. More importantly, the incorporation of ESP at appropriate amount greatly improved water resistance, tensile properties, water vapor and oxygen barrier properties of composite films compared to the control PS/G films. Optimal ESP content in the composite films was found to be ∼30 % w/w in terms of their mechanical and barrier properties, showing a tensile strength of 4.54 MPa, elongation at break of 27.23%, water vapor permeability of 4.16 × 10−10 g m·m−2·s−1·Pa−1 and oxygen permeability of 8.15 × 10−15kg m·m−2·s−1·Pa−1, respectively. Moreover, all the films were able to completely degrade within one month. Thermo-processed PS/G/ESP composite films with desirable physicochemical properties and favorable biodegradability hold great application potential in biodegradable packaging systems.

Preparation and Properties of Novel Mucilage Composite Films Reinforced with Polydimethylsiloxane

AbstractRecently, there is an increasing interest in research on biodegradable, non‐toxic, and high‐strength biomaterials that can replace plastics, especially in the food industry. In this study, mucilage obtained from Linum usitatissimum seeds is used to develop a natural biodegradable biomaterial by reinforcing it with different concentrations of polydimethylsiloxane (PDMS). The biomaterials produced in the form of films are thoroughly investigated in terms of physicochemical (Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy (SEM), energy dispersive X‐ray spectrum (EDX), atomic force microscopy (AFM), contact angle, and mechanical), biodegradable (in soil and water), and antibacterial properties. SEM‐EDX and AFM demonstrate the homogeneous distribution of PDMS throughout the mucilage matrix. The incorporation of PDMS improves the water solubility of the mucilage composite films, thereby enhancing their strength. It also imparts hydrophobic characteristics to the composite films. Thus, PDMS ensures the high barrier property of the composite films against water vapor. Furthermore, the addition of PDMS increases the antimicrobial properties of the mucilage composite films. The obtained results indicate that the first‐time produced mucilage‐PDMS composite films can serve as an alternative product for food packaging applications.

Fabrication of Glycine-Chitosan/TiO2 film for metanil yellow removal from water

This study focused on the modification of chitosan with glycine and TiO2 to improve its performance for adsorption application. It is the first study to use a combination of chitosan, glycine, and TiO2 in the preparation of composite films. The obtained chitosan-glycine/TiO2 composite films were extensively characterized using various techniques, including FT-IR, SEM, XRD, DSC, and tensile tests to study the functional groups, morphology, structure, thermal stability, and mechanical properties of composite films, respectively. FT-IR analysis confirmed the successful formation of the chitosan-glycine/TiO2 film, where chemical interaction occurred between the carboxyl groups of glycine and NH2 of chitosan through a condensation process and physical interaction occurred between chitosan-glycine and TiO2. SEM images revealed that the surface of chitosan-glycine/TiO2 composite films exhibited a rougher texture compared to the unmodified chitosan, indicating structural changes due to the addition of glycine and TiO2. XRD analysis indicated alterations in the crystallinity properties of chitosan upon the incorporation of glycine and TiO2. The DSC results demonstrated that the presence of glycine and TiO2 influences the thermal stability of chitosan. The tensile test revealed the improvement of tensile strength in the chitosan-glycine/TiO2 film, related to the existence of glycine and TiO2. The adsorption process of metanil yellow by the chitosan-glycine/TiO2 film was in accordance with the Langmuir isotherm model. In conclusion, the modification of chitosan with glycine and TiO2 resulted in the development of a promising adsorbent material with improved thermal stability, enhanced tensile strength, and a higher adsorption capacity for metanil yellow. These findings contribute to the potential application of chitosan-glycine/TiO2 films in various adsorption processes.

Preparation and property evaluation of poly(ε-caprolactone)/polylactic acid/perlite biodegradable composite film

Abstract The feasibility of perlite particles used in poly(ε-caprolactone) (PCL)/poly(lactic acid) (PLA) composite films by melt blending is explored to improve their mechanical property and analyze their antibacterial effect. The effect of perlite content on the mechanical, thermal, hydrophilic, and antibacterial properties of composite films is investigated. Results show that incorporation of 10 wt% perlite in PCL/PLA film improves the tensile strength and hydrophilicity by 1.2 times and 25 %, respectively. After perlite addition, the melting crystallization and glass transition temperature of PCL/PLA film are improved. The presence of perlite also confers antibacterial benefits to the composite film. PLA-based materials are used in the fields of medical materials and food packaging, and their ability to degrade in seawater has been a long-standing goal. In this study, the addition of PCL and perlite not only increases various properties and antibacterial effects, but the blending of inorganic materials and organic materials can destroy the link strength of polymer chain segments of organic materials and help them degrade in seawater. The prepared composite film features broad prospects for the development and application of various fields, such as food packaging and medical materials, reduce white pollution in the ocean.

Starch-based active packaging film and its application

Montmorillonite (MMT) was used to improve the performance of starch and nano-ZnO was added to act as antibacterial agent for developing a starch-based active packaging material via solution mixing and casting methods. The effect of MMT and ZnO on the performance of starch films was investigated, and then the composite films were used for cherry preservation. The results indicated that the addition of MMT could improve the mechanical and water-vapor barrier properties of starch films, but it had only a slight impact on optical properties. However, the addition of nano-ZnO could reduce the optical, mechanical, and water vapor barrier properties of composite films. In preservation applications, compared to the other films, the composite films containing nano-ZnO could be beneficial to maintain quality and nutritional value of cherries by slowing down the growth of bacteria and thereby delaying weight loss, decreasing hardness, and decreasing pH and soluble solid content, resulting in a better preservation effect. Therefore, a starch-based active packaging film with good properties and preservation effect was developed with nano-ZnO and MMT, which could be applied in the field of preservation.

Effect of metal seed layer on the critical thickness and photoelectric properties of ultrathin Ag films

To decrease the critical thickness for Ag to form a continuous film and improve the photoelectric properties of the transparent conductive film, the metal seed layer was introduced as a wetting layer, and the metal seed/Ag/AZO composite film was prepared on K9 glass substrates by the magnetron sputtering equipment. The effects of the metal seed layer on both the critical thickness of continuous Ag layer and the photoelectric properties of composite film were investigated. The Al seed layer reduces the critical thickness of the Ag layer to 10 nm, and the square resistance of the Al/Ag (10 nm)/AZO composite film decreases by 5.53 Ω/sq compared to the Ag(10 nm)/AZO bilayer film, while its average transmittance of visible light (380–780 nm) increases by 2.33 %. The Cu seed layer further reduces the critical thickness of the Ag film to 8 nm, and the square resistance of the Cu/Ag(8 nm)/AZO composite film decreases to 9.26 Ω/sq, of which average visible light transmittance reaches 69.34 %. The square resistance of the Cu/Ag (10 nm)/AZO composite film is as low as 7.43 Ω/sq, which is 8.48 Ω/sq lower than that of the Ag (10 nm)/AZO bilayer film.