Three-layer Film Research Articles

Preparation, characterization, and application of edible antibacterial three-layer films based on gelatin–chitosan–corn starch–incorporated nisin

Edible antibacterial three-layer films based on gelatin–chitosan/nisin–corn starch (GEL-CS/N-COS) were developed by layer-by-layer method. The microstructure and intermolecular interaction of the three-layer film was analyzed by SEM, ATR/FTIR, and XRD. Layer-by-layer technology enhanced the ultraviolet–visible light barrier property and elongation at break. In addition, the water solubility was reduced. Nisin was added into the three-layer film to further enhance its thermal stability and antibacterial activity. Importantly, GEL–CS–COS system exhibited good controlled release behavior of nisin. Cherry tomatoes were stored in GEL-CS/N-COS film packaging, and the effect on the shelf life of cherry tomatoes was evaluated. The results show that weight loss and total bacterial count were reduced, and higher firmness and better color were observed during storage for 22 days. These results suggest that developed three-layer film loaded with nisin is a potential antibacterial and edible material for food packaging applications.

Design and fabrication of color coatings for high-performance building-integrated photovoltaics

Materials used on a building’s exterior must have high transmittance and excellent aesthetic design. In this study, the optimum design was achieved by calculating the optical properties and color distribution to fabricate a high-quality multilayer color thin film through sputtering, and a silicon solar panel was equipped with transmissive- and reflective-type color optical thin films. A three-layer color thin film with a Nb2O5/SiO2/Nb2O5 structure exhibited an average transmittance of over 85.96% and a clear blue color. Simultaneously, it maintained a high overall efficiency with a maximum output value greater than 99% of the value of a reference silicon solar cell. Therefore, the sputtered multilayer thin-film coating not only offers a fracile approach to manufacture colorful solar panels, but also has great potential for various industrial applications such as building-integrated solar power generation, automobile production, and glass production.

Fabrication of binary to quaternary PVDF based flexible composite films and ultrathin sandwich structured quaternary PVDF/CB/g-C3N4/BaFe11.5Al0.5O19 composite films for efficient EMI shielding performance

This work reports the facile fabrication of binary, ternary, and quaternary polymer composite films using combinations of Polyvinylidene fluoride (PVDF), Carbon Black (CB), Graphitic carbon nitride (g-C3N4), and Aluminum doped Barium hexaferrite (BaFe11.5Al0.5O19) nanoplatelets for application as EMI shielding materials at X-band frequency. The excellent total EMI-SE of 47.39 dB in X-band for ultra-small thickness of 0.193 mm was observed for the quaternary PVDF/CB/g-C3N4/BaFe11.5Al0.5O19 composite film. The quaternary composite film was further hot pressed into sandwich-structured two-layer and three-layer composite films. The sandwich and/or multi-layered structure of the PVDF/CB/g-C3N4/BaFe11.5Al0.5O19 composite film improved the EMI shielding performance through multiple reflection loss. With the addition of intact conduction of fillers and multiple-reflection-absorption effect, the multi-layered composite structure attained the best shielding efficiency (SE) of 64.54 dB.

Skin-adaptive film dressing with smart-release of growth factors accelerated diabetic wound healing

The general treatment of diabetic wound was use of wound dressings to absorb excess exudate. However, traditional wound dressings neither mimic the skin-like properties nor easily be withdrawn from the wound. Herein, the skin-adaptive three-layered films (AGB) dressing has been designed by alternatively depositing phenylboronic acid-grafted γ-PGA (PBA-PGA) and polyvinyl alcohol (PVA). The thickness of AGB film was only 479 μm and its flexibility was obviously strengthen by the boronic ester cross-linking. Besides, the dry AGB film was conveniently adhered to the fresh wound, where its adhesive force reached to 1267 ± 330 mN. Moreover, the adhered AGB film was easily peeled without any second damage after hydration. An anti-inflammatory tripeptide (KPV) and epidermal growth factor (EGF) as biologic factors were respectively encapsulated in the bottom layer and the middle-top two layers of AGB film. KPV was firstly released within 3 day and EGF was subsequently released in a glucose-responsive manner. AGB film containing KPV and EGF (K-E-AGB) could significantly improve the repair rate of full-thickness skin wound on diabetic mice. The mechanism of wound healing was associated with inflammatory inhibition, angiogenesis and collagen deposition. Collectively, skin-adaptive film may be a promising dressing as delivery of biologic factors for the chronic wound.

A layer-by-layer green inkjet printing methodology for developing indium tin oxide (ITO)-based transparent and conductive nanofilms

A facile, cost-effective, and green inkjet printing methodology is proposed for the fabrication of a transparent and conductive nanostructured indium tin oxide (ITO) thin films. Unlike solution deposition methods, the ITO nanoparticles did not deposit herein on the substrate. Instead, they are formed in-situ during the inkjet printing. The layer-by-layer inkjet printing is conducted stepwise, by printing the indium acetate based ink on a glass substrate, then printing the tin acetate-based inkjet ink onto a dry previously printed layer. Next, heat treatment is carried out leading to the formation of nanostructured ITO thin film. The resulting inkjet-printed sustainable transparent three-layer thin films were characteristic of evenly dispersed ITO nanodomains taking the advantage of appropriate wettability and rheological properties of the engineered ink solution. Surprisingly, the electrical resistivity of thin film drastically dropped (874 times) from 43.72 Ω cm for one-layer (48 nm thickness) to 0.05 Ω cm for three-layer (154 nm thickness) thin films, without sensible drop in optical properties (from 88% to 84% in the same order). In view of sustainability, i.e. low-cost clean inkjet printing, green chemicals used, and water-based synthesis, this novel technique opens new avenues for developing sustainable transparent thin films with superior electrical conductivity.

Effect of Ru Interlayer thickness on Electrophysical Properties of Co/Ru/Co three-layer film systems

In this paper, the investigation of the crystal structure and electrophysical properties of Co/Ru/Co/Sub three-layer film systems with a Ru layer thickness dRu = 5-20 nm has been carried out. It is shown that for both as-deposited and annealed at 800 K thin-film samples the phase composition corresponds to hcp-Co + hcp-Ru. The dependence of resistivity and temperature coefficient of resistance as a function of dRu was received. It was demonstrated that the change in the resistivity value during the first cycle of heat treatment stays more significant than more Ru layer thickness. The value of temperature coefficient of resistance has an order of 10-4 and growth from 5.05×10-4 to 6.42×10-4 K-1 within the dRu range 0-20 nm.

Synthesis of TiO2thin films by a new low-temperature solid-phase pyrolysis technique

Thin TiO2-films were synthesized for the first time by solid-phase low-temperature pyrolysis technique onto quartz glasses or silicon substrates. The obtained films are nanoscale; crystallize in a mixed anatase-rutile modification, which was confirmed by X-ray diffraction, scanning electron and atomic force microscopy (AFM) methods. The three-layer films’ thickness was 140 nm. The TiO2-films consist of crystallites 12–27 nm, depending on the temperature treatment and phase composition. In addition, all of the obtained TiO2-films are optically transparent regardless of synthesis conditions; the calculated band gap was 3.55 eV, which makes it possible to recommend TiO2-films for use in optical filters and gas sensors.

Application of Mixing Rules for Adjusting the Flowability of Virgin and Post-Consumer Polypropylene as an Approach for Design from Recycling

To enable the use of recyclates in thermoformed polypropylene products with acceptable optical appearance and good mechanical stability, a multilayer structure of virgin and recycled material can be used. When producing multilayer films with more than two layers, the used materials should have similar melt flow properties to prevent processing instabilities. In the case of a three-layer film, post-consumer recyclates are often hidden in the core layer. Due to the inconsistent melt flow properties of post-consumer recyclates, the adjustment of the melt flow properties of the core layer to those of the outer layers has to be realized by blending with virgin materials. In order to understand the effect of mixing with a virgin material with a certain pre-defined melt flow rate (MFR), material mixtures with different mixing partners from various sources were realized in this study. Hence, the pre-defined virgin material was mixed with (i) virgin materials, (ii) artificial recyclates out of a mixture of different virgin materials, and (iii) commercially available recyclates. These blends with mixing partner contents ranging from 0–100% in 10% increments were prepared by compounding and the MFR of each mixture was determined. For a mathematical description of the mixing behavior and furthermore for a proper MFR prediction of the material mix, existing mixing rules were tested on the three pre-defined sample groups. Therefore, this paper shows the applicability of different mixing rules for the prediction of the MFR of material blends. Furthermore, a new mixing rule was developed using symbolic regression based on genetic programming, which proved to be the most accurate predictive model.

Antibacterial properties of cinnamic and ferulic acids incorporated to starch and PLA monolayer and multilayer films

Ferulic (F) and cinnamic (C) acids have shown great potential as antimicrobial additives in the development of active food packaging based on biodegradable polymers. However, previous studies on thermo-processed (TP) PLA matrices with 1 or 2%w/w of these compounds found no microbial growth inhibition due to their limited release. In this study, 2 or 3% of F and C were incorporated into starch and PLA films, using several strategies to promote their release from PLA, in order to obtain effective antimicrobial activity against E. coli or L. innocua. TP starch films with F or C presented antimicrobial capacity, C being more effective than F for both bacteria and L. innocua being more sensitive to both acids. However, PLA films obtained by three different techniques: TP, thermo-processing with the addition of plasticiser (TPP), and solvent casting did not exhibit antibacterial action. The incorporation of ferulic acid methyl ester into PLA films did not improve the antimicrobial effect, which suggested that the release limitation may not be related to chemical interactions with the end chain hydroxyl of PLA. Three-layer PLA assemblies, with an internal starch film loaded with F or C, were tested using TP-PLA, TPP-PLA, or cast-PLA films as contact layer. Diffusion of F and C through the PLA layer was highly hindered, regardless of the film preparation method. Therefore, no significant bacterial growth inhibition was observed for the three-layered films. The reduced molecular mobility in the PLA matrix was the limiting factor for the compound release and subsequent antimicrobial effect.

Polarization Maintaining Fiber Temperature and Stress Gradient Sensitization Sensor Based on Semiconductor-Metal-Polymer Three-Layer Film Coating.

Increasing sensitivity, measuring points, and stability have always been the pursuit of sensors. ZnSe9:CO1 and Ag composite nano films were coated on polarization maintaining fiber (PMF). Then, the coated PMF was nested in capillary and hose which was encapsulated with polydimethylsiloxane (PDMS) and epoxy resin. The integrated capillary sensor and thermoplastic hose sensor were prepared. The gradient sensitization of various measurement parameters such as temperature, stress, and micro bending is realized. The temperature sensitivity is 1.49 nm/°C, the micro bending sensitivity is 1.72 nm/102 g, and the stress sensitivity is 6.27 nm/mε. The sensors maintain good linearity and instantaneous response while having high sensitivity. By adjusting the length of PMF, the number of troughs is increased in the same band range, and different troughs have different sensitivities, which solves the inherent problem of cross sensitivity and realizes multiparameter measurement. Capillary sensors are used for remote safe real-time monitoring of mechanical overheating, and hose sensors are used for real-time monitoring of bridge load and human joint bending. This work is of great significance to the extension of the application range of optical fiber sensor.

Comparative analysis by UV-vis and FT-IR spectroscopy of the chemical degradation of polyethylene used as greenhouse cover film

Greenhouse culture usually requires a controlled environment for optimum plant growth and production. However, regular plastic films used for their coverage create an uncontrolled microclimate, especially in areas with harsh climatic conditions. Three low-density polyethylene (LDPE) films, a commercial ordinary film, a three-layer film, and a monolayer film were used as a greenhouse covering materials to study its behavior in presence of a cultivar and harsh climatic conditions. They were exposed to natural weathering and UV radiations in the semi-arid environment of a city located in northern Algeria. This study aims to investigate and compare the lifespan and deterioration of the materials used for a 5-month period to improve future greenhouse cultivation. Fourier-transform infrared spectroscopy (FT-IR) and ultraviolet-visible spectrophotometry (UV-vis) were used to study the aging and degradation of these films. FTIR 1030/2848 bands ratio was used to determine the chemical oxidation rate of each film. Visible changes in the material structure were also recorded during the aging process. Materials underwent photo and thermo degradation, leading to chemical and mechanical changes. The monolayer film has suffered more mechanical degradation than the multilayer films, leading to its total crumbling in a short lifetime. The three-layer and ordinary films were more resistant and showed approximately the same behavior towards the rough climatic conditions. Furthermore, the UV-visible spectrum indicated a high loss of transparency of the polyethylene films during their use. The two studied multilayer films seem more adequate for greenhouse culture under the semi-arid regions.

Functional gradient films on aluminum alloy with high absorption efficiencies and damage thresholds for inertial confinement fusion applications

Functional gradient films with high absorption efficiencies and damage thresholds are crucial for eliminating stray light to decrease laser-induced damage in optical systems. Recent advances related to aluminum-based functional films have attracted much attention. However, the fabrication of large area of metal frame need to satisfy low cost, absorb stray light and high stability. A three-layer functional gradient film is designed here. The bottom barrier layer is non-porous alumina, the middle absorption layer has CdSe-quantum dots embedded in anodic aluminum oxide nanopores, and the anodic aluminum film was sealed by a silica layer at the outer side. It could be mass produced at low cost on large areas on aluminum-alloy substrates and have high damage thresholds. The average measured absorbance of light was over 95% over the range 300–750 nm. Moreover, the prepared process has capability to be operated with large scale and high efficiency in an industrial plant. The aluminum-based functional gradient films has its potential to be used in large sized laser facility manufacturing like building inertial-confinement fusion systems to eliminate stay light and improve system cleanliness.

Magnetoelectric properties of three-layered composite thin film fabricated by pulsed laser deposition

Magnetostriction-piezoelectric composite films present promising application prospects due to the presence of the magnetoelectric effect. In this paper, a sandwich structure Bi4Ti3O12/CoFe2O4/Bi4Ti3O12 composite film was prepared in a pulsed laser deposition system. The morphology, EDX, XPS, ferroelectric, piezoelectric, ferromagnetic and magnetoelectric properties were investigated in detail. In the sample, the atomic percentages of Bi, Ti and O elements measured by EDX are 35.373%, 12.824% and 46.578%, respectively. The out-of-plane electric domain structure and the in-plane magnetic domain structure show that BTO and CFO phases have excellent ferroelectricity (Pr = 1.57 μC/cm−2) and ferromagnetism (Mr = 104.83 emu/cc), respectively. The piezoelectric properties are proportional to the ferroelectric properties, so the composite thin films also have good piezoelectric properties (d33max = 192 p.m./v). Moreover, a great magnetoelectric coupling coefficient (∼11.95 mV/cm·Oe) was obtained by mechanical strain transfer and interface coupling. By adding a ferroelectric layer to the composite thin film, the clamping effect can be reduced and the coupling between the ferroelectric and the ferromagnetic layers can be increased, providing the experimental basis for the research of magnetoelectric coupling effect.

Migration of Irganox 1010, Irganox 1076, and Titanium dioxide into Doogh and corresponding food simulant from laminated packaging.

Doogh is a famous Iranian drink based on fermented milk. Laminated film is one of the most common packaging for this beverage in Iran. So, chemical substances of the packaging may migrate to the Doogh and endanger human health. In this research, High-Performance Liquid Chromatography (HPLC) was used to determine the migration of Irganox 1010 and Irganox 1076 from the contact layer and inductively coupled plasma for Titanium dioxide (TiO2) from the second layer of three-layer laminate films into Doogh and acetic acid 3% (w/v). The influence of different storage temperatures and times was investigated by evaluating the samples stored in various conditions. The morphological, thermal and mechanical properties of the film, before and after contact with food simulant were further studied. The highest amount of Irganox 1010 concentration of the tested samples were 0.8 ± 0.04mg/l in acetic acid 3% (w/v), and 0.62 ± 0.04mg/l in Doogh. The highest amount of TiO2 concentration were 0.25 ± 0.04mg/l in acetic acid 3% (w/v), and 0.12 ± 0.02mg/l in Doogh. The migration of Irganox 1076 was determined, but it was not detected. The results indicated that the food simulant had no significant effect on the microstructure and thermal properties of the polymer, but it reduced the mechanical properties. The results indicate the possible migrating of Irganox 1010 and TiO2 through laminate packaging into Doogh in some storage conditions. Since the migration value was low, the mentioned film was proven safe for Doogh packaging, imposing no hazards on human health.

Dimensional Effects in Magnetoresistive Properties in Three-Layer Films

Dimensional Effects in Magnetoresistive Properties in Three-Layer Films

Temperature dependences of the interlayer exchange constant of three-layer FeNi/Dy/FeNi films studied by the resonance method

Three-layer FeNi/Dy/FeNi films were studied by ferromagnetic resonance method in the temperature range from 4 to 300 K. The acoustic and optical peaks recorded in microwave spectra demonstrate the presence of exchange coupling between the ferromagnetic FeNi layers of the planar system and allow us to establish the sign and value of the constant of the interlayer exchange interaction. Temperature dependences of the interlayer exchange interaction constant for three-layer films with intermediate layer thicknesses Dy 5 and 10 nm show a number of features (change in sign and extremum point), which reflect transformations of the magnetic structure Dy. Keywords: interlayer exchange coupling, helical magnetic structure, ferromagnetic resonance, three-layer films.

Температурные зависимости межслойной обменной константы трехслойных пленок FeNi/Dy/FeNi, исследованные динамическим методом

Three-layer FeNi/Dy/FeNi films were studied by the ferromagnetic resonance method in the temperature range from 4 to 300 К. The detected acoustic and optical peaks in the microwave absorption spectra demonstrate that there is exchange coupling between the ferromagnetic FeNi layers of the planar system, which allows us to define the sign and value of the interlayer exchange interaction constant. The temperature dependences of the interlayer exchange constant of the three-layer films with an interlayer thickness of Dy equal to 5 and 10 nm show a number of features (change of the sign and extreme point) which reflect the transformation of the Dy magnetic structure

Comparative Analysis of the Functional Properties of Films Based on Carrageenans, Chitosan, and Their Polyelectrolyte Complexes

The influence of the structural features of carrageenan on the functional properties of the films was studied. The carrageenans and chitosan films, as well as three-layer films containing a polyelectrolyte complex (PEC) of the two, were prepared. The X-ray diffractograms of carrageenan films reflected its amorphous structure, whereas chitosan and three-layer films were characterized by strong reflection in the regions of 20° and 15° angles, respectively. The SEM of the cross-sectional morphology showed dense packing of the chitosan film, as well as the layer-by-layer structure of different densities for the PEC. Among the tested samples, κ/β-carrageenan and chitosan films showed the highest tensile strength and maximum elongation. Films containing the drug substance echinochrome were obtained. Mucoadhesive properties were assessed as the ability of the films to swell on the mucous tissue and their erosion after contact with the mucosa. All studied films exhibited mucoadhesive properties. All studied films exhibited mucoadhesive properties which depended on the carrageenans structure. Multilayer films are stronger than single-layer carrageenan films due to PEC formation. The resulting puncture strength of the obtained films was comparable to that of commercial samples described in the literature.

Study on the Characteristics of MAO/Polymer/Ni Three-Layer Composite Film formed on AZ31 Magnesium Alloy

Study on the Characteristics of MAO/Polymer/Ni Three-Layer Composite Film formed on AZ31 Magnesium Alloy

Design and Implementation of 6 × 6 Array Piezoelectric AlN Hydrophone With High Sensitivity

This paper presents the design, fabrication and characterization of a MEMS piezoelectric hydrophone based on Silicon-On-Insulator (SOI), using Aluminum Nitride (AlN) as the functional piezoelectrical material. The hydrophone has a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${6}\times {6}$ </tex-math></inline-formula> array and a sandwich structure composed of Molybdenum-Aluminum-Molybdenum (Mo-AlN-Mo) films. The three-layered films adhere back cavities that have a radius of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$200~ \boldsymbol {\mu }\text{m}$ </tex-math></inline-formula> and a pitch of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$400~ \boldsymbol {\mu }\text{m}$ </tex-math></inline-formula> . The hydrophone shows proximal resonance frequencies of 479 kHz and 476 kHz under Impedance and Doppler tests, respectively. The initial deformation of the diaphragm is avoided by using a hollow PCB in the packaging to keep the hydrophone in a pressure-equalizing environment. The hydrophone is characterized in both water and air platforms. In water, the hydrophone has a sensitivity of −172.6 dB in the range of 100-2000 Hz, and a linearity of 99% at 1000 Hz, whereas in air it has a linearity of 98% at 1000 Hz. These results demonstrate the potential of high performance miniaturized hydrophone systems for wide-band and low-frequency applications.