Properties Of Films Research Articles

Improvement of electrical and optoelectronic properties of ZnO thin films by plasma nitridation treatment

Understanding and controlling the effects of trap sites in ZnO semiconductors are crucial for optimizing device performance and enabling various technological applications. To passivate the trap sites, the N atoms are incorporated into polycrystalline ZnO thin films via a plasma nitridation (PN) process using NH3 gas. The results show that the contact resistivity, sheet resistance, and transfer length of the ZnO photodetector are improved after the PN treatment. The photo-to-dark current ratio (PDCR) and responsivity values increase from 42.52 to 103.19 and from 344.36 A/W to 5727.63 A/W, respectively, after the PN treatment. This improvement in photodetector properties is attributed to the introduced N atoms, which effectively reduce the trap sites in the ZnO thin film. This PN treatment technology has the potential to improve device performance in both electronic and optoelectronic applications.

Pectin Film Fortified with Zein Nanoparticles and Fe3+-Encapsulated Propolis Extract for Enhanced Fruit Preservation

In this study, pectin served as the film matrix while propolis extract (PPE) acted as both an antibacterial agent and antioxidant. Utilizing the encapsulation of zein nanoparticles and cross-linking of Fe3+ with pectin molecules, a dual encapsulation system of PPE in the pectin film was successfully achieved, resulting in antibacterial and antioxidant pectin films. The effects of incorporating PPE, zein, and Fe3+ on various properties of the pectin films were investigated. Additionally, the impact of zein nanoparticle encapsulation and Fe3+ dual encapsulation systems on the release characteristics of PPE in the pectin films was examined. Characterization techniques including FTIR, SEM, XRD crystal diffraction, and thermogravimetric analysis were employed to analyze the interactions, microstructure, crystal structure, and thermal stability of the films. The results showed that the double cross-linking of zein and Fe3+ led to a reduction in the moisture content of the pectin film by approximately 46%, a decrease in water vapor permeability by about 19%, an almost doubling of tensile strength and antioxidant activity, and a significant improvement in antibacterial properties. Additionally, the incorporation of zein and Fe3+ enhanced the release characteristics of PPE in the pectin films. Notably, the developed composite coating demonstrated improved preservation properties during the storage of strawberry fruits.

Study on impact wear and damage mechanisms of DLC films on TC4 and 9Cr18 alloys

As a classic film-resistant coating, DLC film is widely used in the field of impact wear. The impact wear properties of DLC films with different thicknesses (1.1 μm thin DLC film and 7.9 μm thick DLC film) on various substrates (9Cr18 and TC4) were evaluated. On the TC4 substrate, the experimental results demonstrate that the thick DLC film offers obvious damage and serious impact wear, but the thin DLC film exhibits reduced deformation and wear. On the 9Cr18 substrate, both thick and thin DLC films work successfully in protecting the substrate. The failure mechanisms of the two DLC films are mainly abrasive wear (thin DLC film) and adhesive wear (thick DLC film). The thin DLC film with the highest hardness, toughness, and adhesion represents the best protective coating for impact dynamic load applications examined, regardless of whether the substrate is soft or hard.

Tailored multilayered films of the PVDF/Ba0.8Sr0.2TiO3 nanocomposites with surface-modified nanoparticles for superior dielectric and energy storage performance

The multilayer thick film (~40 μm) of polyvinylidene fluoride-Ba0.8Sr0.2TiO3 (PVDF-BST) have been synthesized by a tape-casting technique. The incorporated BST nanoparticles in the PVDF matrix are functionalized by −PO4−3and −OH−group, which are abbreviated as PBST-P and PBST-H multilayer films. The nature of the functional group attached with the BST nanoparticles is found to strongly influence the dielectric properties, breakdown strength and energy storage behavior of the multilayer films. The dielectric constant (at 1kHz) of PBST-P multilayer film shows a significant increase (~30) as compared to PBST-H film (~22), whereas the tangent loss remains the same. The breakdown strength of PBST-P multilayer film is also high (~381MV/m) as compared to the PBST-H film (~318MV/m). PBST-P film also possesses high discharge energy density (~7.97J/cc at 1800 kV) and ultrahigh energy efficiency (~98%). Enhanced dielectric and energy storage properties of PBST-P film is attributed to the strong bridging interaction between the PVDF matrix and BST-P nanofiller, which creates additional dipoles and a strong local electric field at the interfaces. The study may lead towards the novel ways of developing polymer-ceramic nanocomposites for high-energy density capacitors, where the incorporation of functionalized nanoparticles in the polymer matrix is accompanied by the architectured structure.

Effect of N2 reactive gas flow rate on the structural, optical and wettability properties of silicon carbon oxynitride thin films

In the current research, the silicon carbon oxynitride (SiCON) thin film was deposited on the silicon (Si) substrate by radio frequency (RF) reactive magnetron sputtering method. To comprehensively assess the impact of nitrogen flux rate on thin film characteristics, a suite of advanced analytical methods was utilized. The GIXRD analysis confirmed that the SiCON thin film is amorphous in structure. Additionally, Raman spectroscopy detected no graphite nanocrystals within the film. Ellipsometry measurements further showed that the refractive index of the thin films rises with increased nitrogen flux in the reactive gas, indicating a direct correlation between nitrogen concentration during deposition and optical properties. Based on the designs made with McLeod's software, the amount of reflection can be reduced up to 5.7% at the wavelength of 4 μm and up to 8.5% in the wavelength range of 3-5 μm for an optimal thickness thin film. The atomic force microscopy (AFM) examination revealed that the surface roughness of the thin films decreases as the nitrogen flux in the reactive gas mixture increases. Additionally, measurements of the water contact angle (WCA) indicated that the SiCON thin films exhibit a hydrophilic state.

Naphthalene-embedded spiropyran derivative-A type of conjugated expanded material with solid-state photochromic properties and tunable color switching range

Due to the limited free volume in the solid state, spiropyrans generally exhibit photochromic properties in solution or mixed thin films. However, few spiropyrans can display the photoisomerization process in the solid state. One conventional solution for solid-state photochromism is to embed the spiropyran on polymer chains or introduce bulky groups to create an efficient free volume in the solid state. In this article, we attempt to introduce large conjugated fragments on the spiropyran backbone to construct a donor-acceptor (D-A) building block that not only possesses an enlarged π-electron system with enhanced electronic delocalization capability but also exhibits an improved free volume for efficient solid-state photoisomerization. Through this strategy, we have successfully embedded the naphthalene ring on the spiropyran backbone to obtain a novel D-A type conjugated building block, SP-Naph, which exhibits excellent solid-state photochromic performance and reversibility. Furthermore, the D-A structure of SP-Naph significantly tuned its photochromic color-switching range to blue. Consequently, SP-Naph was successfully applied in optical printing and invisible inks. The excellent solid photochromic properties make it exhibit remarkable photochromic effects, indicating significant potential for optical printing and anti-counterfeiting applications.

Fluorinated polyaniline-based sensors with enhanced NH3 sensitivity

Poly(2-fluoroaniline) films were prepared by electrochemical oxidation of 2-fluoroaniline in perchloric acid solutions. These films had a characteristic globular structure, but low thickness and conductivity. For these reasons, alternative polymer films were prepared from electrolytic solutions with different aniline:2-fluoroaniline ratios. The physicochemical properties of these polymer films strongly evolved with the ratio since they were thicker and more conductive when the proportion of aniline increased while their morphology also varied significantly. The electrodeposited polymer films were then used as sensitive layers of gas sensors for ammonia detection. The addition of 2-fluoroaniline improved the performance characteristics of gas sensors for the detection of ammonia at room temperature and the poly(aniline/2-fluoroaniline)-based sensors responded to ammonia gas with good repeatability, good sensitivity (0.44 %/ppb), a very low detection limit (4 ppb), and a low dependence on humidity variations.

Ultra-fast switching of energy efficient electrochromic nickel oxide thin films for smart window applications

In today's modern world, energy consumption continues to escalate. In such cases, smart windows play a crucial role in reducing energy consumption and enhancing the quality of life. Electrochromic devices (ECDs) -based smart windows rely profoundly on nickel oxide (NiO) thin films, which act as a counter electrode in ECDs. This work aims to fabricate NiO thin films, with the intention of achieving ultrafast ECD. Through the sputtering technique, energy- efficient ECD is obtained with the highest optical modulation of 60% at a rapid switching speed of 0.55s for bleaching and 0.95s for coloration. We have also investigated the structural, morphological, vibrational, and optical properties of NiO thin films. XRD analysis revealed the less crystalline or near amorphous nature of NiO thin film. XPS, PL, and Raman studies confirm the existence of defects in the film. The favourable, less crystalline nature, along with the presence of defects, facilitates ultra- fast ion intercalation and de-intercalation process. We believe that prepared NiO film can be used as a promising anodic colourant in electrochromic smart windows with applications in energy-efficient buildings.

A microfluidic and Langmuir approach to unveil the interplay between hydroxypropyl methylcellulose and zein nanoparticles on the stability of Pickering emulsions

Utilizing microfluidic technology and Langmuir trough, the study investigated how hydroxypropyl methylcellulose (HPMC) interact with zein nanoparticles (ZNPs) at interfaces and their collective impact on emulsion stability. Herein, microchips were designed with varying adsorption channel lengths to study the effect of adsorption kinetics on the coalescence stability, while Langmuir assessments provided insights into particle adsorption kinetic and film properties of emulsion stabilization mechanisms. Results suggested that HPMC's incorporation expedited ZNPs' rearrangement rates at the interface, especially at low concentrations, resulting in a synergistic reduction in interfacial tension. However, at high HPMC concentration, a competitive adsorption scenario emerged between ZNPs and HPMC, leading to increased interfacial tension and instability. Microfluidic analyses of droplet coalescence, alongside Langmuir-derived interfacial rheology data, revealed that while a small amount of HPMC significantly bolstered emulsion stability by enhancing viscoelastic properties of interfacial film, an excess of HPMC inversely affected these parameters, diminishing film elasticity and thus, the emulsion's coalescence resistance. The adsorption kinetic and the interaction on interface of HPMC and zein particles were analyzed via microfluidic and LB technology in this study, which will not only expand our current strategies for interface engineering of emulsions, but also deepens our understanding of the interplay between mixed particle system adsorption properties, interfacial rheology, and Pickering composite emulsion stability.

MXene-CNC super performing composite films for flexible and degradable electronics

Flexible electronics have gained significant interest due to their potential applications in wearable devices, biomedical sensors, and flexible displays. This study explores the combination of MXene and cellulose nanocrystals (CNC) for the development of flexible, conductive, and degradable materials. CNC and MXene are high-performance nanomaterials with known degradability. CNC can self-assemble into highly ordered layers and act as an ideal structural companion for enabling large surface MXene-based devices with outstanding performance. Three fabrication routes are explored in this work: self-assembly, drop casting, and dip coating. The mechanical and electrical properties of the CNC-MXene composite films were assessed. Tensile testing revealed that dip-coated films in high-loadings of MXene could exhibit enhanced toughness of up to 1.9 MJ‧m−3, higher than pure MXene or CNC. The electrical conductivity of the films varied depending on MXene concentration and drying, exhibiting superior conductivity in self-assembly with higher MXene loading and rapid drying that prevents oxidation. Self-assembled MXene-CNC with a 1:3 MXene-to-CNC ratio maintained high conductivity of 2.2 × 105 S‧m−1. Zeta potential measurements indicate that CNC enhances the stability of MXene dispersion. These findings demonstrate good synergy between CNC and MXenes for applications in flexible, transparent, and environmentally degradable electronic.

Pectin film fortified with zein nanoparticles and Fe3+-Encapsulated propolis extract for enhanced fruit preservation

In this study, pectin served as the film matrix while propolis extract (PPE) acted as both an antibacterial agent and antioxidant. Utilizing the encapsulation of zein nanoparticles and cross-linking of Fe3+ with pectin molecules, a dual encapsulation system of PPE in the pectin film was successfully achieved, resulting in antibacterial and antioxidant pectin films. The effects of incorporating PPE, zein, and Fe3+ on various properties of the pectin films were investigated. Additionally, the impact of zein nanoparticle encapsulation and Fe3+ dual encapsulation systems on the release characteristics of PPE in the pectin films was examined. Characterization techniques including FTIR, SEM, XRD crystal diffraction, and thermogravimetric analysis were employed to analyze the interactions, microstructure, crystal structure, and thermal stability of the films. The results showed that the double cross-linking of zein and Fe3+ led to a reduction in the moisture content of the pectin film by approximately 46%, a decrease in water vapor permeability by about 19%, an almost doubling of tensile strength and antioxidant activity, and a significant improvement in antibacterial properties. Additionally, the incorporation of zein and Fe3+ enhanced the release characteristics of PPE in the pectin films. Notably, the developed composite coating demonstrated improved preservation properties during the storage of strawberry fruits.

Influence of Gamma-Ray Irradiation on Polystyrene Food Container Weathering

Conventional plastics, such as polystyrene (PS), are widely used due to their high degradation stability, which makes them suitable for various applications. However, the downside of this property is that it results in the persistence of these plastics in the environment, contributing to plastic pollution. This paper investigated the effects of gamma-ray irradiation on the mechanical, optical, structural, thermal, and morphological properties of PS food containers subjected to natural (NW) and artificial weathering (AW). First, the PS films were exposed to a source of 60Co-γ at doses of 0, 10, and 45 kGy, and then they were subjected to NW for 0-190 days and AW for 0-500 hours. The mechanical properties of the PS films (tensile strength and elongation at break) were evaluated under NW and AW conditions, revealing an acceleration factor (AF) ranging from 3.8 to 6.2. According to the results, gamma-irradiation had a complex and uneven effect on the physicochemical properties of the weathered PS films. The type of weathering and conditions under which the exposures were performed, in conjunction with the irradiation doses, provided a comprehensive analysis of the effects of gamma-ray irradiation on PS food containers. These results are relevant for extending PS food containers' longevity rather than increasing their degradation.

Cysteines in β-lactoglobulin affects its interfacial adsorption and protein film stabilization

HypothesisDisulfide bonds in proteins are strong chemical bonds forming the secondary and tertiary structure like in the dairy protein β-lactoglobulin. We hypothesize that the partial or complete removal of disulfide bonds affects the structural rearrangement of proteins caused by intra- and intermolecular interactions that in turn define the interfacial activity of proteins at oil/water interfaces. The experimental and numerical investigations contribute to the mechanistic understanding of the structure-function relationship, especially for the interfacial adsorption behavior of proteins. Experimental and numericalSystematically, the 5 cysteines of β-lactoglobulin were recombinantly exchanged by alanine. First, the protein structure of the variants in bulk was analyzed with Fourier-transform-infrared-spectroscopy and molecular dynamic simulations. Second, the structural changes after adsorption to the interface have been also analyzed by molecular dynamic simulations. The adsorption behavior was investigated by pendant drop analysis and the interfacial film properties by dilatational rheology. FindingsThe structural flexibility of β-lactoglobulin with no cysteines encourages its unfolding at the interface, and accelerates the interfacial protein film formation that results in more visco-elastic films in comparison to the reference.

Numerical and experimental investigation of 2-Thiazoline-2-Thiol and Nitrotetrazolium Blue Chloride compound as levelers for through-hole copper electroplating

Leveler is essential in the electroplating process of the through-hole (TH), the adsorption characteristics of which are strongly influenced by the aspect ratios of the THs. However, only a single kind of leveler usually appears in the most frequently performed THs’ filling electrolyte, which is highly possible to limit the electrolyte's capability to fill THs and improve the copper film properties. In this paper, two levelers, 2-Thiazoline-2-Thiol (T1) and Nitrotetrazolium Blue chloride (NBT), with significant molecular weight differences, were combined to fill THs with multiple ARs. The interactions among the leveler compounds and other additives become the primary factor controlling the THs electroplating process, which was systematically investigated through a combination of flow field numerical simulation and electrochemical measurements. T1 presents a weaker inhibition effect and is more sensitive to convection than NBT, which also exhibits a convection-enhanced inhibition effect with other additives. The convection of the electrolyte in the THs center continuously decreases with the ARs, guiding to the increasing electroplating rate at the THs center, high throwing power (TP) of 141%, and flawless filling of the THs with ARs of 4.75:1~1.9:1 in 2.5h. The copper film on the surface maintains extremely high flatness and low thickness.

Deposition of hydrogenated amorphous carbon films by CH4/Ar capacitively coupled plasma using tailored voltage waveform discharges

We investigated the effects of tailored voltage waveform (TVW) discharges on the deposition of hydrogenated amorphous carbon (a-C:H) films in CH4/Ar capacitively coupled plasma. TVW discharges employ two driving radio frequencies (13.56 MHz and 27.12 MHz) and control their phase shifts to independently regulate ion bombardment energy (IBE) and ion flux. In this study, a-C:H films were deposited by changing DC-self bias with phase shift and constant applied voltage peak-to-peak. Additionally, we investigated phase-resolved optical emission spectroscopy (PROES) for plasma characterization. As a result, plasma-enhanced CVD (PECVD) for a-C:H films using TVW discharges realize control of film properties such as mass density, sp3 fraction, and H content, while keeping the deposition rate constant. Thus, it is suggested that TVW discharges realize the independent control of IBE and ion flux with high accuracy, highlighting its utility in a-C:H film depositions.

Polymer-like hydrogenated amorphous carbon thin films fabricated by plasma-enhanced chemical vapor deposition of cyclohexane precursor

Hydrogenated amorphous carbon (a-C:H) films were fabricated by plasma-enhanced chemical vapor deposition (PECVD) of a cyclohexane precursor at ambient temperature at varying deposition pressures from 19.73 to 38.00 Pa and varying plasma powers from 20 to 80 W. The deposition rate of the a-C:H films was strongly dependent on the deposition conditions. The films were all optically transparent with extinction coefficient below 0.0042. The refractive index as an indicator of the film’s density varied depending on the deposition conditions. Their surfaces were all hydrophobic regardless of the deposition conditions. The a-C:H films had wide optical bandgaps ranging from 3.09 to 3.69 eV. The refractive index and FTIR spectra were consistent with those of polymer-like a-C:H films. As the deposition pressure decreased and plasma power increased, the intensity of a dominant peak of CHx stretching mode in the FTIR spectra decreased. The relative hydrogen content of the a-C:H films was estimated from an FTIR analysis and determined to have an inverse relationship with refractive index. These results indicated that the formation of more energetic plasmas during deposition at lower pressures and higher plasma powers led to the a-C:H films with reduced hydrogen content and increased density. The observed film properties could be advantageous for several applications, particularly as protective, wear-resistant, low-friction, or anti-reflective coatings for optical windows.

Pectin extracted from red dragon fruit (Hylocereus polyrhizus) peel and its usage in edible film

Pectin was extracted from red dragon fruit (Hylocereus polyrhizus) peel using two different extraction methods: subcritical water extraction (SCWE) and conventional acid extraction (AE), from two different types of peels, fresh peel puree and dried peel powder. SCWE method on fresh peel puree showed an ~18.88 % increase in pectin yield compared to AE. Extracted pectin is classified as low methoxyl pectin (DE: 8.51–50.64 %), with an average molecular weight ranging from 115.23 kDa to 577.84 kDa and a Gal-A content of 44.09 % - 53.90 %. The potential of pectin from fresh peel puree to be applied as a biodegradable film was further explored. Different pectin concentrations (3–5 % w/v) were used to prepare the films. Regarding the film performance, PF-S5, which was produced from SCWE with 5 % of pectin concentration, exhibits better thermal stability (Tdmax 250 °C, residue of 28.69 %) and higher moisture barrier (WVP 5.59 × 10−11 g.cm−1.s−1.Pa−1). In comparison, PF-A showed lower water solubility (45.14–69.15 %), higher water contact angle (33.01° - 44.35°), and better mechanical properties (TS: 2.12–4.11 MPa, EB: 48.72–61.39 %). Higher molecular weight accompanied by higher DE and Gal-A content contributes to better pectin film properties.

Structure of Biomolecular Films Through Advanced Imaging and Statistical Analysis

This manuscript is dedicated to advancing the understanding of biomolecular film on solid target formation, with a particular emphasis on the intricacies of structure nonuniformities in amino acid and protein-based dehydrated films. Experimental and theoretical studying the structure of films at the quantitative level has been created and tested. By integrating advanced imaging and statistical analysis, we dissect the dynamics and intricacies of domain structures, including cellular and microcrystalline formations, that significantly influence dehydrated biomolecular film properties. The research process entails preparing amino acid and protein solutions, capturing high-resolution images during dehydration, and implementing advanced digital image processing techniques like Laplacian Pyramid Restoration and Gaussian Differential Scale-Invariance for enhanced image clarity. Analytical approach includes domain segmentation and texture analysis using Haralick features, enabling precise quantification of structural complexities in films formed under various dehydration conditions and protein concentrations. The suggested physical model describes the transition from equilibrium solutions through nonequilibrium processes to complex bubble vaporization, dehydration-induced Dewetting and domain differentiation, thus explained observed spiral formations within protein domains. This model provids a detailed mechanistic understanding of how environmental conditions and molecular dynamics drive the formation of domains, paving the way for developing films with tailored properties for diverse applications. These insights hold significant implications across various fields, including material science, nanotechnology, biomedical applications, environmental monitoring, electronics, and photonics.

IMPLEMENTATION OF MAGNETRON SPUTTERING METHOD IN OBTAINING A RADIO-ABSORBING THIN FILM BASED ON CoC

This paper describes the main results of the study of obtaining samples of radio-absorbing CoC films by magnetron sputtering and evaluates the data of experimental and computational studies on the relationship between the structure and properties of CoC films. To eliminate the ferromagnetic effect of cobalt, a composite target was used. The use of the composite target during magnetron sputtering ensures the production of films of a given and necessary composition. Structural-phase state of the obtained films was studied using XRD, SEM and TEM methods. A distinctive feature of the synthesized coating is the absence of a crystalline structure in some areas due to the amorphizing properties of cobalt and its tendency to form metallic glasses. Results obtained by the experiments are in good agreement with computational modeling results. The radio-absorbing properties of the obtained films were confirmed by the results of measuring the reflection loss, standing wave ratio, reflectance, and impedance. Results presented in the article can serve as a baseline for perspective studies in this field.

Nickel Salt Dependency as Catalyst in the Plating Bath on the Film Properties of Cu/Cu-Ni

Metal plating frequently employs nickel (Ni) and copper (Cu) as anodes. Cu/ Cu-Ni film formed has many advantages, such as better corrosion resistance and high hardness characteristics. This study aims to assess the properties of Cu/Cu-Ni film, such as phase, surface morphology, crystallographic orientation, hardness, corrosion analysis, and contact angle, which were fabricated using electrodeposition with various Ni salt additions (0.3, 0.5 and 0.7 M). In addition, the cathode current efficiency (CCE) and deposition rate of the Cu/Cu-Ni electrodeposition were also investigated. An increase in Ni salt in the plating bath could enhance the pH, promoting higher CCE and depleting hydrogen evolution at the cathode, leading to the presenting Ni phase in the alloy. The higher concentration of Ni salt in the solution could also enhance the deposition rate due to a shift to a pH value, which affects the roughening of the surface morphology, promoting a higher contact angle. All crystal structures generated by Cu/Cu-Ni electrodeposition were FCC, with the preferred orientation of the (111) plane. Crystallite size and lattice strain depend on the deposition rate. Less crystallite size and lattice strain affect the film’s hardness and corrosion resistance. Moreover, the third bath had the resulting Cu-Ni layer with the best hardness and corrosion rate of around 136 HV and 0.081 mmpy.