Properties Of Films Research Articles

Development of Multifunctional Sustainable Packaging from Acetylated Cellulose Micro-Nanofibrils (CMNF)

Cellulose micro-nanofibrils (CMNF) with different fibrillation levels were partially acetylated while preserving their morphological and native crystalline structure. The morphological changes due to fibrillation and chemical modification were observed using Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) and optical profilometry. The change in tensile and burst strength, barrier, and biodegradability profile were investigated which revealed that the mechanical properties of the unmodified CMNF films increased with increase in extent of fibrillation. However, the mechanical strength of the acetylated film decreased with the increase in degree of acetylation. The stretching or folding property of the film increased with the increase in both the fibrillation and acetylation. The contact angle value increased due to a higher degree of fibrillation and acetylation because they increased the hydrophobicity and consequently enhanced the air and water vapor resistance of the unmodified and modified CNF films. Furthermore, all films exhibited the highest resistance against oil and grease, and the biodegradability test substantiated that CNF films were compostable in soil. In total, this work expresses new pathways to enhance the barrier properties of biodegradable CNF films by regulating the degree of fibrillation and acetylation, thus can emerge as sustainable alternatives to for packaging and agriculture applications.

Lignin-enhanced wet strength and UV-Blocking properties of nanocellulose-based composite films obtained by casting/hot-pressing methods

We composited nanocellulose, lignin and polyvinyl alcohol (PVA) by using borax as a cross-linking agent, and prepared nanocellulose-based composite films by two simple and convenient methods of the casting and hot-pressing. Results showed that the molding method affected the film properties. The hot-pressing composite film exhibited smoother surface and tighter structures, while the casting one exhibited better stretchability. The composite films showed a good tensile strength (casting: 149.56 MPa; hot-pressing: 179.68 MPa). Due to the addition of lignin, the composite films were endowed with good UV-blocking capabilities, wet strength, oxidation resistance and bacteriostatic properties. The composite film has good application prospects in the field of food packaging and UV-shielding.

The structural and optical properties of PVA/CMC copolymer cured by UV irradiation for different times

Poly(vinyl alcohol) (PVA)/carboxymethylcellulose (CMC) blend films with equal amounts (0.25 g) of both polymers were prepared through a simple and low-cost comparative casting method. Then, the PVA/CMC blend films were exposed to ultraviolet (UV) radiation for varied time intervals (1, 12, 26, 32, 40 and 48 h). The UV-irradiation effect on the physical properties of as-prepared films, including the structure, morphology, composite and optical properties (transmittance, absorbance and band gap (E g)), was examined. Field-emission scanning electron microscopy images showed that UV irradiation had a strong effect on the shape of PVA/CMC blend films. The X-ray diffraction patterns showed various crystalline qualities in the microstructure of as-synthesized samples. The Fourier transform infrared spectra showed that the UV-irradiation time and CMC film had a positive impact on the blend polymer structure since covalent connections were formed between CMC and PVA. Furthermore, the analysis results of optical inspections showed that the absorbance of the PVA/CMC films improved with an increment in irradiation time from 1 to 40 h. Important tuning of the E g values of blend films was realized. It showed a slight increase from 4.64 to 4.84 eV with increasing irradiation time from 1 to 40 h. The E g value (3.21 eV), however, displayed an inverted behavior due to an increased irradiation time of 48 h. This reduction could be ascribed to the creation of defects inside the blend band gap. Finally, the physical property modification of PVA/CMC blend film using UV irradiation made it an amazing contender in the optoelectronic field.

Anticorrosion and adhesion performance of a monolayer and double layer silane-epoxy coating systems applied on carbon steel

Carbon steel is one of the widely used metallic material, although its limited corrosion resistance. To improve its anti-corrosion performance, organic coatings such as epoxy have been an excellent option due to their barrier mechanism. Nevertheless, the elevated brittleness and porosity observed in this type of coating, coupled with the weak bonding interface between epoxy and carbon steel, significantly hampered their protective capabilities. The organofunctional silanes are candidates to be used as pre-treatment between epoxy coating and carbon steel interface because of their good corrosion resistance but as a limitation they can present small pores and microcracks.Therefore, the anticorrosive and mechanical properties of silane films can be adapted and further improved by strengthening the coatings through some modifications, such as the incorporation of green corrosion inhibitors into the film, reducing the access of aggressive species to the metal. In this context, the objective of this research is to evaluate the adhesion and anticorrosive properties of an epoxy-based organic coating pre-treated with a silane film obtained by tetraethoxysilane (TEOS) with γ-glycidoxypropyltrimethoxysilane (GPTMS) modified with the garlic peel powder as a corrosion inhibitor (Allium sativum L.). The investigation of the surface features as morphology and the corrosion resistance of the silane-epoxy coatings were studied by scanning electron microscope (SEM) and electrochemical characterization techniques, such as, electrochemical impedance spectroscopy (EIS), linear and potentiodynamic polarization. Also, the coating adherence was evaluated by pull-off tests. The results of the EIS showed that all samples coated with silane+ epoxy coating have better anticorrosion performance than the sample coated with just epoxy painting. Besides, SEM images showed that the silane film improved the cohesion between substrate and coating system, with the clear appearance of delamination in the system silane free. In general, the results of these different techniques indicate that the film modified with the natural inhibitor has improved anticorrosive properties compared to the film without silane or natural green inhibitors.

Realization of ferroelectricity in sputtered Al1-xScxN films with a wide range of Sc content

The ferroelectric properties of wurtzite-structured Al1-xScxN thin films are affected simultaneously by the Sc concentration and in-plane stress state, however, the interaction between these two factors remains unclear. In this work, a series of Al1-xScxN films were deposited on (111) Si substrate by dual-target co-sputtering. X-ray diffraction analyses show the films with a wide range of Sc content (x= 0.05 - 0.50) have the (0002)-textured wurtzite structure and are in compressive stress state. Ferroelectricity in all the films is confirmed by polarization hysteresis loop measurements at room temperature, and the coercive field exhibits an interesting non-monotonic transition due to the competition between in-plane stress and Sc incorporation. The results provide insight into the wurtzite-structure stability and the nature of ferroelectricity for Al1-xScxN thin films.

Study of the optical properties of aluminum films and the effect of current frequency on plasma parameters

Study of the optical properties of aluminum films and the effect of current frequency on plasma parameters

Structure, magnetic and magnetocaloric properties of the Mn5Ge3 thin film grown on Si(111)

Structure, magnetic and magnetocaloric properties of the Mn5Ge3 thin film grown on Si(111)

Modification of WS2 thin film properties using high dose gamma irradiation

The tunability of the transition metal dichalcogenide properties has gained attention from numerous researchers due to their wide application in various fields including quantum technology. In the present work, WS2 has been deposited on fluorine doped tin oxide substrate and its properties have been studied systematically. These samples were irradiated using gamma radiation for various doses, and the effect on structural, morphological, optical and electrical properties has been reported. The crystallinity of the material is observed to be decreased, and the results are well supported by x-ray diffraction, Raman spectroscopy techniques. The increase in grain boundaries has been supported by the agglomeration observed in the scanning electron microscopy micrographs. The XPS results of WS2 after gamma irradiation show evolution of oxygen, carbon, C=O, W–O and SO4 −2 peaks, confirming the addition of impurities and formation of point defect. The gamma irradiation creates point defects, and their density increases considerably with increasing gamma dosage. These defects crucially altered the structural, optical and electrical properties of the material. The reduction in the optical band gap with increased gamma irradiation is evident from the absorption spectra and respective Tauc plots. The I–V graphs show a 1000-fold increase in the saturation current after 100 kGy gamma irradiation dose. This work has explored the gamma irradiation effect on the WS2 and suggests substantial modification in the material and enhancement in electrical properties.

Electrical properties of AgNbO3 thick films by aerosol deposition followed by post-annealing in oxygen atmosphere

Electrical properties of AgNbO3 thick films by aerosol deposition followed by post-annealing in oxygen atmosphere

Enhanced photoluminescence characteristics in Mg doped Alq3: An insight into doping mechanism

The present paper deals with the investigations on the effect of Mg doping on the structural and photophysical properties of Alq3 thin films. Mg doped Alq3 powders, with varying Mg concentrations, are synthesized using co-precipitation method and their thin films are deposited using vacuum evaporation method. These films are subjected to different analytical analyses to study the effect of Mg doping on the structural and photophysical properties of Alq3. It has been observed that Mg is attached at the central part of the Alq3 molecules making bonds with Al, N and O atoms. In this process, Mg atoms transfer electrons to Alq3 molecules and increases the electron density in its highest occupied molecular orbital (HOMO). Increased HOMO electron density in Mg doped Alq3 results in the improvement in its photoluminescence characteristics. Highest photoluminescent characteristics are observed for Mg doped Alq3 having 1.5 % (by mole) Mg which shows almost 2-fold enhancement in photoluminescence quantum efficiency (PLQY) and 3-fold enhancement in radiative decay rate. The results obtained in this work suggest that Mg doped Alq3 films may be integrated in high performing organic light emitting devices.

Influence of Flow Rates and Flow Times of Plasma-Enhanced Atomic Layer Deposition Purge Gas on TiN Thin Film Properties

Influence of Flow Rates and Flow Times of Plasma-Enhanced Atomic Layer Deposition Purge Gas on TiN Thin Film Properties

Studies on the structural, optical, and optoelectrical properties of innovative Li2ZnSnS4 thin films deposited by nebulizer spray pyrolysis

Studies on the structural, optical, and optoelectrical properties of innovative Li2ZnSnS4 thin films deposited by nebulizer spray pyrolysis

Integration Of Solution‐Processed BaTiO3 Thin Films with High Pockels Coefficient on Photonic Platforms

AbstractThe heterogeneous integration of ferroelectric BaTiO3 thin films on silicon (Si) and silicon nitride (SiN)‐based platforms for photonic integrated circuits (PICs) plays a crucial role in the development of future nanophotonic thin film modulators. Since the electro‐optic (EO) properties of ferroelectric thin films strongly depend on their crystal phase and texture, the integration of BaTiO3 thin films on these platforms is far from trivial. So far, a conventional integration route using a SrTiO3 template film in combination with high vacuum deposition methods has been developed, but it has a low throughput, is expensive and requires monocrystalline substrates. To close this gap, a cost‐efficient, high‐throughput and scalable method for integrating highly textured BaTiO3 films is needed. Therefore, an alternative method for the integration of highly textured BaTiO3 films using a La2O2CO3 template film in combination with a chemical solution deposition (CSD) process is presented. In this work, the structural and EO properties of the solution‐processed BaTiO3 film are characterized and its integration into an optical ring resonator is evaluated. The BaTiO3 film exhibits a fiber texture, has a large Pockels coefficient (reff) of 139 pm V−1, and integration into a ring resonator‐based modulator shows a VπL of 1.881 V cm and a bandwidth of > 40 GHz. This enables low‐cost, high‐throughput, and flexible integration of BaTiO3 films on PIC platforms and the potential large‐scale fabrication of nanophotonic BaTiO3 thin‐film modulators.

Phosphonic Chloride Assisted Fabrication of Highly Emissive Mixed Halide Perovskite Films in Ambient Air for Blue Light-Emitting Diodes.

Blue perovskite light-emitting diodes (LEDs) have emerged as promising candidates for full-color display and lighting applications. However, the fabrication of blue-emitting perovskite films typically requires an inert environment, leading to increased complexity and cost in the manufacturing process, which is undesirable for applications of perovskite LEDs. Herein, we report a strategy to fabricate bright blue-emitting perovskite films in ambient air by incorporating phosphonic chlorides in a perovskite precursor solution. We used two different phosphonic chlorides, diphenylphosphonic chloride (DPPC) and phenylphosphonic dichloride (PPDC), and comparatively studied their effects on the properties of perovskite films and the blue LEDs. It is found that PPDC possesses a stronger chlorination ability due to higher hydrolysis reactivity; meanwhile, it has a stronger interaction with the perovskite compared to DPPC, resulting in an improved film quality and enhanced blue emission with a photoluminescence quantum yield of 45%, which represents the record value for the air-processed blue perovskite films. Blue perovskite LEDs are fabricated, and the emission wavelengths are effectively tuned by controlling the concentration of phosphonic chlorides. Benefiting from the optimized perovskite films with reduced nonradiative recombination and promoted charge injection and transport, the PPDC-derived blue perovskite LEDs exhibit improved performance with an external quantum efficiency of 3.3% and 1.2% for the 490 and 480 nm emission wavelength, respectively.

Combined effects of substrate temperature and post annealing temperature on structural, optical and electrical properties of Sb-doped SnO2 films

Sb-doped SnO2 (ATO) films have received extensive attention as transparent conductive films, but there is still a lack of in-depth and systematic study on combined effects of substrate temperature (Ts) and annealing temperature (Ta) on their transparent conductive properties. In this study, ATO films were prepared using RF magnetron sputtering at RT∼400 ℃ and subsequently annealed at 200–1000 ℃. The results show that the conductive properties of the films enhance (with a decrease in resistivity from 1.15×10-1 to 2.15×10-3 Ω•cm) and the average visible-light transmittance (TVis) decreases (90.16 → 38.24%) with increase of Ts. With the increase of Ta, the conductive properties of the films prepared at different Ts tend to first enhance and then degrade, and the TVis basically shows a trend of first decreasing and then increasing. After annealing at 600 ℃, the films prepared at RT and 100 ℃ can achieve better comprehensive properties (resistivity of 2.50×10-3 and 1.64×10-3 Ω•cm, carrier concentration of 3.35×1020 and 4.93×1020 cm-3, mobility of 7.73 and 7.76 cm2/V•s, sheet resistance of 84 and 55 Ω/sq., and TVis of 86.63 and 79.50%). In order to explore the intrinsic mechanism of the optical and electrical performance of ATO films changing with Ts and Ta, the preferred orientation, crystallinity, and stress state of the films were analyzed by XRD, and their surface morphology was observed by SEM. Meanwhile, the chemical states of Sn, O and Sb as well as Sb content in the films were analyzed by XPS, and their lattice vibration modes of the film were studied by Raman spectra. Finally, the process-structure-properties correlations were established for the ATO films.

Enhancement of Colorimetric pH-Sensitive Film Incorporating Amomum tsao-ko Essential Oil as Antibacterial for Mantis Shrimp Spoilage Tracking and Fresh-Keeping

Anthocyanin-based smart packaging has been widely used for food freshness monitoring, but it cannot meet the requirements of smart films with antibacterial properties. This study aimed to enhance the antibacterial properties of intelligent films by incorporating Amomum tsao-ko essential oil (AEO) for mantis shrimp spoilage tracking and keeping the product fresh. A smart film was designed by introducing AEO and purple potato anthocyanin (PPA) to a polyvinyl alcohol/cellulose nanocrystal (PVA/CNC) polymer matrix. Our findings revealed that APP and AEO imparted the smart film with a favorable oxygen barrier, UV protection, mechanical properties, and antioxidant and pH/NH3-sensitive functions. Interestingly, the PVA/CNC-AEO-PPA film achieved 45.41% and 48.25% bactericidal efficacy against S. putrefaciens and V. parahaemolyticus, respectively. Furthermore, a visual observation confirmed that the target film (PVA/CNC-AEO-PPA) changed color significantly during mantis shrimp spoilage: rose red—light red—pink—light gray—dark gray. Meanwhile, the PVA/CNC-AEO-PPA film retarded the quality deterioration of the mantis shrimp effectively. The PVA/CNC-AEO-PPA film shows great application potential in mantis shrimp preservation and freshness monitoring; it is expected to become a rapid sensor for detecting seafood quality non-destructively and a multifunctional film for better preservation of product quality.

Chitosan, Poly(vinyl alcohol) and Chitosan/Poly(vinyl alcohol) based active films loaded with white turmeric powder for food packaging applications

In recent years packaging materials made of biodegradable polymers received considerable attention. The packaging system containing antimicrobial agents was one of the new methods that have an advantage over the conventional system. This work aims to fabricate and characterize antibacterial films based on chitosan (CS) and poly(vinyl alcohol) (PVA) incorporated with white turmeric powder (WT) for food packaging applications. The active films of chitosan/cetrimide/white turmeric (CCW), poly(vinyl alcohol)/cetrimide/white turmeric (PCW) and PVA/CS/CT/WT (PCCW) with varied concentrations of WT were prepared by solvent casting method. The influence of WT on the physical and structural properties of the prepared films were studied using different analytical techniques. The results of SEM analysis indicated interactions of polymer matrix with WT contributed to homogeneous, compact and smooth surface morphology. The Fourier Transform Infrared (FTIR) Spectroscopy and X-ray diffraction (XRD) analysis revealed hydrogen bond formation with a polymer matrix that improved the physical and thermal properties. The research findings revealed that there was an improvement in the tensile strength, moisture adsorption, solubility and hydrophobicity of CCW active films with an increase in WT content. At the same time, there was an improvement in inhibiting bacterial growth with increasing concentration of WT for all the fabricated films. The results showed better mechanical and antibacterial properties for PCCW films. All the films exhibited biodegradation under environmental conditions. All these results suggested WT incorporated CS and PVA based films can be used in the food packaging industry to enhance the safety and quality of the packaging material.

Modification of PEDOT:PSS thin film properties using pyridine-based solid additive for optoelectronic applications

Abstract Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) is one of the most promising hole transport layers that is widely used in high-performance optoelectronic devices. However, the hygroscopic nature and acidity of PEDOT:PSS is known to cause degradation in devices and decrease their performance. In this study, a new pyridine solid additive, 2,3-dihydropyridine (2,3-DHP) was incorporated into the PEDOT:PSS solution to improve its characteristics. A low-temperature solution-based spin-coating device was utilized to produce the thin films. From the results, the PEDOT:PSS@2,3-DHP (1 wt%) exhibited excellent optical characteristics. It also provided informative and controlled morphology when it was annealed at 100 oC, suggesting that PEDOT:PSS@2,3-DHP has a potential advantage in photovoltaic (PV) devices. Moreover, in the photodetection experiment utilizing LED of 380 nm, PEDOT:PSS@2,3-DHP showed a higher photocurrent response when compared with pristine PEDOT:PSS. It also significantly reduced sheet resistance and achieved superior electrical conductivity. Interaction between the 2,3-DHP, PEDOT, and PSS chains altered the mechanical properties of the PEDOT:PSS, leading to the modification in structural and electrical characteristics. Overall, these findings highlight the importance and applicability of PEDOT:PSS@2,3-DHP in a wide range of optoelectronic devices.

Evaluating Free Thermal Expansion and Glass Transition of Ultrathin Polymer Films on Heated Liquid.

Thermomechanical properties of ultrathin films are crucial for fabrication and use of reliable thin electronic devices. Due to the lack of precise measurement techniques, the thermal deformation behavior of ultrathin films has not yet been clarified. Here, we propose a film on heated liquid (FOHL) method to simultaneously measure the coefficient of thermal expansion (CTE) and glass transition temperature (Tg) of multiple ultrathin polymer films. Free thermal expansion of thin films without substrate interaction can be guaranteed when the thin films are afloat on a liquid surface. To investigate the thermal behavior in a wide temperature range, glycerol is adopted as a thermally stable heating platform owing to its high boiling point of 290 °C. The thin films are transferred onto the glycerol surface from the water surface using the hygroscopic properties of glycerol. Highly accurate and high-throughput thermal strain measurement is achieved using three-dimensional digital image correlation (3D-DIC). The thermomechanical properties of ultrathin polystyrene thin films of various thicknesses (25-400 nm) are precisely characterized utilizing the FOHL and 3D-DIC method.

Fabrication, Structural Characterization, Dielectric Analysis and Thermal Properties of Novel Flexible Polymer Composite Films

Abstract The films were characterized by different methods as FTIR, SEM, XRD and TGA to prove the efficient manufacturing of the composite. The dielectric performance measurements were done at frequency of 20 Hz to 6 MHz for the polymer PET and the composite (PPy-Fe2O3)/PET with varying concentrations of Fe2O3. Moreover, to reveal the characteristics of the fabricated composite, the contact angle, the work of adhesion, surface energy of the composite PET/(PPy-Fe2O3) films were considerably determined. The SEM results support the deposition of PPy-Fe2O3 composite on the PET surface. The water contact angle drops from 78.32 o for PET to 40.11o for PET/6%(PPy-Fe2O3), while the dispersive free energy raised from 23.9 mJ/m2 to 43.7 mJ/m2and the polar free energy rises from 8.9 mJ/m2 to 22.3 mJ/m2. The concentration of Fe2O3 increased the surface features of the samples, according to the obtained results. At frequency of 100 Hz, the dielectric constant enhanced from 18 for PET to 923 for the PET/6%(PPy-Fe2O3), and the dielectric loss improved from 24 to 9231, while the energy density improved fromm 7.9x10-5 J/m3 for PET to 408x10-5 J/m3. The TGA results show marginal modifications in thermal stability after deposition the PPy/Fe2O3 on the PET film.