Physical Properties Of Films Research Articles

Effect of candelilla wax on functional properties of biopolymer emulsion films – A comparative study

The overall research objective was to compare the effects of increasing concentrations of candelilla wax (CnW) on the physicochemical and morphological properties of edible films based on different biopolymers: carboxymethyl cellulose (CMC), oxidized potato starch (OPS), soy protein isolate (SPI), and gelatin (GEL). The findings are discussed in terms of the stability of emulsion formulations. CnW was incorporated into film-forming solutions at 0, 0.5, 1.0, 1.5, and 2.0%; sorbitol and Tween 40 were used as the plasticizer and surfactant, respectively. It was found that, with the exception of GEL films, wax incorporation significantly decreased the WVP of the films (from 11.1 to 41.7% compared to the controls). Regardless of the wax concentration used, OPS films had the lowest WVP compared to other films. GEL-based films, in turn, were characterized by the highest mechanical resistance and elongation. The incorporation of CnW decreased both all the analyzed tensile parameters and the puncture strength of the films. Generally, as CnW concentration increased, the transparency and redness of the films decreased, while UV blocking ability and yellowness increased. The 0.5% CnW addition was the most effective in improving water barrier properties, and simultaneously had the lowest impact on the other physical properties of films. For OPS, SPI, and GEL films, sorbitol recrystallization was observed over time. Wax accelerated the sorbitol crystal growth process. CMC films, in contrast to those obtained using other polymers, were completely water soluble and did not exhibit sorbitol crystallization. The emulsion films differed from the wax-free in their surface characteristics.

Gelatin-based films additivated with curcuma ethanol extract: Antioxidant activity and physical properties of films

Curcuma longa L. rhizomes contain curcuminoid pigments (more specifically, curcumin), which are phenolic compounds. These compounds can be incorporated into films for their functional properties (such as their antioxidant capacity), allowing this film to be used as food packaging. Thus, the aim of this study was to use curcuma ethanol extract to prepare gelatin-based films and evaluate the effects of the extract incorporation on the antioxidant and physical properties of the films. The gelatin-based films were produced by casting technique, and the curcuma ethanol extract (CEE) was incorporated at concentrations of 0, 5, 50, 100, 150, and 200 g/100 g of gelatin. The color parameters, light transmission, gloss measurements, microstructure, infrared spectroscopy characteristics, mechanical properties, moisture content, water-soluble matter, water vapor permeability and antioxidant capacity of the films were evaluated. Adding CEE to the gelatin-based films increased their ultraviolet and visible light barrier. Infrared spectroscopy analysis suggested there were interactions between the phenolic compounds of the extract and the gelatin, which may have improved the mechanical properties (tensile strength and elongation at break) and reduced both the water-soluble matter and water vapor permeability of the films. The antioxidant capacity of the films increased with increasing concentrations of CEE. The incorporation of curcuma ethanol extract conferred barrier properties and antioxidant capacity to the gelatin-based films.

Effects of nano‐clay type and content on the physical properties of sesame seed meal protein composite films

SummarySesame seed meal protein (SSMP)/nano‐clay composite films were prepared, and the physical properties of the films were determined. The SSMP film was prepared with 5 g of SSMP and 2 g of glycerol in 100 mL of film‐forming solution, and the tensile strength (TS), elongation (E) and water vapour permeability (WVP) of the SSMP film were 2.51 MP, 21.84% and 3.23 × 10−9 g m m−2s−1 Pa−1, respectively. Two types of nano‐clays were incorporated to enhance the physical properties of the SSMP film. The TSs of the SSMP film with 5% Cloisite Na+ and 7% Cloisite 10A were 6.32 and 5.76 MPa, respectively, and the WVPs of the SSMP nanocomposite films were 2.04 × 10−9 g m m−2s−1 Pa−1 compared with the SSMP film without nano‐clay, which was 3.23 × 10−9 g m m−2s−1 Pa−1. Therefore, these results indicate that the SSMP nanocomposite film can be applied in food packaging.

RETRACTED: Effect of thermal annealing on P3HT:PCBM bulk-heterojunction organic solar cells: A critical review

The main focus of this review article is to introduce the reader to the advantage and limitation of organic solar cells and to understand how the thermal annealing process could improve performance of organic solar cells. The article explores the operation principles of organic photovoltaic (OPV) device and reviews the effects of thermal annealing on bulk-heterojunction organic solar cells based on a thin film blend of poly (3-hexylthiophene-2,5 diyl) (P3HT) and [6,6]-phenyl-C61 butyric acid methyl ester (PCBM). It focuses on changes in the physical film properties, the electronic performance of devices, as well as the link between film structure and electronic performance during a thermal annealing process. Analysis of film and electrical characteristics, as a function of thermal annealing parameters, indicates that a balancing is established. The balancing between charge conduction and excitonic dissociation leads to the establishment of optimal annealing conditions for maximized electronic performance. Additionally, the report highlights research areas that require attention for future development of this technology.

Water Vapor Permeability, Optical and Mechanical Properties of Salep-Based Edible Film

This study investigates the mechanical and physical properties of salep-based edible film. Samples of edible film with varying glycerol concentrations and dry material contents were prepared and studied. The results showed that increasing the dry material content in the film solution from 1% (w/v) to 2% (w/v) decreased water vapor permeability; however, increasing the dry material content from 2% (w/v) to 3% (w/v) increased water vapor permeability. Increasing the dry material and glycerol content increased the tensile strength from 11.82 to 24.5 MPa, the percentage of film length up to the breaking point from 16.16 to 94.3% and the salep edible film thickness from 0.021 to 0.060 mm. This research demonstrated that palmate tuber salep provides the required physical and mechanical properties to give it great potential for use in edible film production. Practical Applications Salep was used as an edible film-forming material. Glycerol was found to be the most effective and stable plasticizer for the film. The physical properties of the film and also its barrier to water were investigated. Salep has potential value as a carbohydrate source that can be used to form biopolymer edible films for packaging of low and intermediate water activity food products. The edible salep films prepared in the present investigation can be applied to food packaging.

β-Phase poly(vinylidene fluoride) films encouraged more homogeneous cell distribution and more significant deposition of fibronectin towards the cell–material interface compared to α-phase poly(vinylidene fluoride) films

The piezoelectric response from β-phase poly(vinylidene fluoride) (PVDF) can potentially be exploited for biomedical application. We hypothesized that α and β-phase PVDF exert direct but different influence on cellular behavior. α- and β-phase PVDF films were synthesized through solution casting and characterized with FT-IR, XRD, AFM and PFM to ensure successful fabrication of α and β-phase PVDF films. Cellular evaluation with L929 mouse fibroblasts over one-week was conducted with AlamarBlue® metabolic assay and PicoGreen® proliferation assay. Immunostaining of fibronectin investigated the extent and distribution of extracellular matrix deposition. Image saliency analysis quantified differences in cellular distribution on the PVDF films. Our results showed that β-phase PVDF films with the largest area expressing piezoelectric effect elicited highest cell metabolic activity at day 3 of culture. Increased fibronectin adsorption towards the cell–material interface was shown on β-phase PVDF films. Image saliency analysis showed that fibroblasts on β-phase PVDF films were more homogeneously distributed than on α-phase PVDF films. Taken collectively, the different molecular packing of α and β-phase PVDF resulted in differing physical properties of films, which in turn induced differences in cellular behaviors. Further analysis of how α and β-phase PVDF may evoke specific cellular behavior to suit particular application will be intriguing.

The effect of solution concentration on the physical and electrochemical properties of vanadium oxide films deposited by spray pyrolysis

Vanadium oxide thin films were prepared on glass substrates by using the spray pyrolysis technique. The effect of solution concentration (0.1 M, 0.2 M and 0.3 M) on the nanostructural, electrical, optical, and electrochromic properties of deposited films were investigated using X-ray diffraction, scanning electron microscopy, UV—vis spectroscopy, and cyclic volta-metrics. The X-ray diffraction shows that only the sample at 0.1 M has a single β-V2O5 phase and the others have mixed phases of vanadium oxide. The lowest sheet resistance was obtained for the samples prepared at 0.3 M solution. It was also found that the optical transparency of the samples changes from 70% to 35% and the optical band gap of the samples was in the range of 2.20 to 2.41 eV, depending on the morality of solution. The cycle voltammogram shows that the sample prepared at 0.3 M has one-step electerochoromic but the other samples have two-step electerochoromic. The results show a correlation between the cycle voltammogram and the physical properties of the films.

Novel self‐crosslinking film from hydrogenated carboxylated nitrile rubber latex

ABSTRACTA new type of self‐crosslinking latex film was prepared from hydrogenated carboxylated nitrile‐butadiene rubber (HXNBR) latex by diimide reduction. The properties of the HXNBR rubber, including film surface morphology, physical properties, thermal stability and ageing properties, were investigated. FTIR spectroscopy was used to confirm the HXNBR structure, from which the degree of hydrogenation can be obtained. The morphology of the film surface was monitored by atomic force microscopy, which confirmed that HXNBR latex can form a continuous film with good cohesive properties from self‐crosslinking latex particles. The self‐crosslinking provided the latex film with excellent tensile strength. The thermal stability was improved after hydrogenation, as indicated by thermogravimetric methods. The activation energy for degradation was determined by Coats‐Redfern plots. Hot air oven thermal ageing confirmed that the oxidation resistance increased as the degree of hydrogenation increased. All these results showed that HXNBR latex can form a self‐crosslinking film with better mechanical properties, and heat and oxidation resistance than those of XNBR latex film in a wide range of film applications. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39865.

Immobilization of sericin molecules via amorphous carbon plasma modified-polystyrene dish for serum-free culture

In this study, we focused on sericin hydrolysates, originating from silkworm used in serum-free human bone marrow-derived mesenchymal stem cells (hBM-MSCs) culture. We reported the effect of a covalent linkage between a bioactive protein molecule and polystyrene dish surface via a carbon intermediate layer which can slow down the release rate of protein compounds into the phosphate buffer saline (PBS) solution. Films of amorphous carbon (a-C) and functionalized-carbon were deposited on PS culture dish surfaces by using a DC magnetron sputtering system and RF PECVD system. We found that a-C based-films can increase the hydrophilicity and biocompatibility of polystyrene (PS) dishes, especially a-C films and a-C:N2 films showed good attachment of hBM-MSCs at 24h. However, in the case of silica surface (a-C:SiOx films), the cells showed a ragged and unattached boundary resulting from the presence of surface silanol groups. For the UV–vis absorbance, all carbon modified-PS dishes showed a lower release rate of sericin molecules into PBS solution than PS control. This revealed that the functionalized carbon could be enhanced by specific binding properties with given molecules. The carbon-coated PS dishes grafting with sericin protein were used in a serum-free condition. We also found that hBM-MSCs have higher percentage of proliferated cells at day 7 for the modified dishes with carbon films and coated with sericin than the PS control coated with sericin. The physical film properties were measured by atomic force microscopy (AFM), scanning electron microscope (SEM) and contact angle measurement. The presence of NH2 groups of sericin compounds on the PS dish was revealed by Fourier transform infrared spectroscopy (FTIR). The stability of covalent bonds of sericin molecules after washing out ungrafted sericin was confirmed by X-ray photoelectron spectroscopy (XPS).

Antilisterial and physical properties of biopolymer films containing lactic acid bacteria

Novel biopolymer films were developed and used to control Listeria innocua in an artificially contaminated synthetized medium. Two hydrocolloids, sodium caseinate (NaCas) and methylcellulose (MC), and two bacteriocin-producing lactic acid bacteria (LAB), Lactobacillus acidophilus and Lactobacillus reuteri, were tested. Bioactive cultures were added directly to the film forming solution and films were obtained by casting. In order to study the impact of the incorporation of bacterial cells into the biopolymer matrix, the water vapour permeability, optical and mechanical properties of the dry films were evaluated. Furthermore, the survival of LAB and the antimicrobial potential of bioactive films against L. innocua were studied. Results showed that the use of lactic acid bacteria altered the film's physical properties. Films enriched with bacterial cells exhibit higher gloss and transparency whereas no significant modifications were observed in terms of tensile properties. These films were less-effective water vapour barriers, since a significant increase can be observed in the WVP values. As far as food safety is concerned, these films are an interesting, novel approach. In refrigeration conditions, these films permit a complete inhibition of L. innocua for a week. Viability of LAB was higher in sodium caseinate films, although bacteriocin production was greater in polysaccharide matrix. The best results were obtained for films made of methylcellulose, without differences between the two lactic acid bacteria tested.

Atomisation rate and gas/liquid interactions in a pipe and a venturi: Influence of the physical properties of the liquid film

The aim of this study is to better understand and model atomisation phenomena occurring in a venturi metre under air/oil and air/water annular flows. First, the structure of the liquid film was observed using a high-speed video camera in the pipe section upstream of the venturi, and along the convergent section: the surface waves and regimes visualised were described and compared with the literature, which highlighted the influence of the liquid film physical properties. Some of these surface waves, corresponding to disturbance waves as described in the literature, seem to be at the origin of consequent atomisation. These disturbance waves were then characterised through calculation of their velocities and comparison with the literature: a calculation procedure was defined and showed the influence of parameters such as air superficial velocities, wave height, liquid viscosity, interfacial friction velocity and flow regimes. Another aspect of the atomisation modelling consists in modelling both the location of the beginning of atomisation and the atomisation rate inside the venturi. The video records showed that, contrary to what is often assumed in some studies, a consequent atomisation may start at the middle of the convergent section, depending on the surface waves occurring at that time. Finally, a correlation law for the atomisation rate is proposed, based on the literature and measurements on air/water and air/oil flows.

Trout‐Skin Gelatin‐Based Edible Films Containing Phenolic Antioxidants: Effect on Physical Properties and Oxidative Stability of Cod‐Liver Oil Model Food

Trout-skin (Oncorhynchus mykiss) gelatin-based films containing antioxidants (epigallocatechin gallate (EGCG), 50 and 250 ppm w/w) and green tea powder (1% and 20% w/w of gelatin) were tested for tensile strength, elastic modulus, and elongation, and oxygen and water vapor transmission rates, in vitro antioxidant activity using the DPPH (2,2-diphenyl-1-picrylhydrazyl) assay and effect on stabilizing cod-liver oil held under mild thermal abuse conditions. Cod-liver oil overlaid with films was stored at 40 °C for 20 d and analyzed for peroxide value (PV) and thiobarbituric acid reactive substances (TBARS). Antioxidant activity was retained in films containing green tea powder, but was reduced (P < 0.05) in EGCG films (20 d, 23 °C). Water vapor transmission rate of the films incorporated with antioxidants did not change significantly (P > 0.05), but the oxygen transmission rate for films with 50 ppm EGCG and 20% green tea powder was significant (P < 0.05). Other physical properties varied with antioxidant incorporation. The TBARS and PV of control oil increased from 0.05 ± 0.01 to 4.71 ± 0.30 g MDA/kg oil and from 3.6 ± 0.2 to 178.3 ± 24.5 millieq peroxides/kg oil, respectively, after 20 d. For cod-liver oil covered with control or antioxidant-containing films, TBARS remained below 0.37 g MDA/kg oil and PV below 7 millieq peroxides/kg oil. Incorporation of antioxidants to the films did not reduce oil oxidation (P > 0.05) at the levels tested and this was confirmed by activation energy calculations. The rate of oil oxidation was more dependent upon the inherent oxygen barrier property of the films than the presence of antioxidants. This research has the potential to enhance the utilization of fish skins, a valuable food processing by-product, as edible films with natural antioxidants to extend the shelf life of foods. The film physical properties and barrier to oxygen and water are investigated.

Systems and control challenges in photovoltaic manufacturing processes: A modeling strategy for passivation and antireflection films

A view of contemporary systems and control challenges in photovoltaic cell manufacturing is given in this paper, with emphasis on developing a modeling strategy for the optimization of silicon nitride SiNx:H films used for passivation and antireflection coatings in single and multicrystalline silicon solar cells. The overall framework integrates three modeling modules: a remote plasma-enhanced chemical vapor deposition reactor process model that predicts film composition and thickness based on process input parameters, a solar-optical module that relates antireflection film physical and chemical properties to the degree to which the spectral irradiance distribution is attenuated, and a solar cell device model that predicts cell power output and efficiency from the film properties and irradiance. Because the model couples process inputs to both photovoltaic cell performance and manufacturing process efficiency, the modeling approach can be used for the simultaneous optimization of process and product performance.

Physical and Antimicrobial Properties of Tapioca Starch-HPMC Edible Films Incorporated with Nisin and/or Potassium Sorbate

The antimicrobial effectiveness of nisin and potassium sorbate, incorporated individual and combined, in films made with tapioca starch and its mixtures with hydroxypropyl methylcellulose were studied. The combination of antimicrobials was more effective against Listeria innocua and Zygosaccharomyces bailii than their individual incorporation, with the added advantage of providing greater inhibitory spectrum. The effect of the formulation on some physical properties was also evaluated. The blended biopolymers-based films showed an increase of stress (σr) and elastic modulus (E) but a decrease of the strain at break (er). In turn, the water vapour permeability and solubility in water were enhanced. In addition, these films were clearer than those made only with starch. It must be remark that, despite the antimicrobial agents modified films physical properties, producing a lower σr and E, a higher er, solubility and darker films, they maintained a suitable behaviour as a packaging material.

Structural defects in trifluoroacetate derived YBa2Cu3O7 thin films

We present an accurate description of the structural defects occurring within YBa2Cu3O7 (YBCO) films grown by chemical solution deposition (CSD) based on metal trifluoroacetates (TFA). Transmission electron microscopy (TEM) is the essential tool to identify and evaluate the microstructural defects that might act as natural pinning centers. Our study of TFA–YBCO thin films shows that the YBCO thin films contain a variety of extended defects, such as intergrowths, twin boundaries and dislocations, mainly in the basal plane. These extended defects and their interaction make up a rich variety of key microstructural features that play an important role in the YBCO thin films physical properties and performance.

Pulsed Laser Assisted Polycrystalline Growth of Oxide Thin Films for Efficient Processing

ABSTRACTWe have investigated the polycrystalline growth by means of an excimer laser assisted metal organic deposition process and the strategy for the efficient growth. It was revealed that the pulsed photo thermal heating properties must be controlled by changing the laser fluence according to the substrate properties, such as thermal diffusivity. The threshold of the teff value for initial crystal nucleation is approximately 70 ns for oxide thin films. For the fabrication of good quality films with high crystallinity and without a laser ablation of the film surface, it is necessary that the irradiated laser fluence is adjusted to the conditions of teff (efficient annealing time) &gt; 70 ns and Tmax (maximum temperature) &lt; Tm (melting point). Obtained oxide films by using the pulsed UV laser has large crystallite size, and it well functioned to enhance physical properties of films. For further efficient growth for polycrystalline growth of the oxide films, the starting solution containing nanoparticles is very useful: it is named as photo-reaction of nanoparticles process.

Physical Properties of Nano-Composite Silica-Phosphate Thin Film Prepared by Sol Gel Technique

A series of silica-phosphate nano-composites prepared as a host thin films Physical Properties of Nano-Composite Silica-Phosphate Thin Film Prepared by Sol Gel Technique and doped with different concentrations of Er3+ ions have been synthesized using tetraesoxysilane TEOS, triethylphosphate TEP and erbium nitrate as precursor sources of silica, phosphorus and erbium oxides. The structural properties of pure silica-phosphate thin films and doped with different concentrations of Er3+ ions were studied, using x-ray diffraction (XRD) and Fourier Transform Infrared (FTIR). The morphology of silica-phosphate was characterized by Scanning electron microscope (SEM).

Characterization of Hf1-xZrxO2 Gate Dielectrics with 0≤x≤1 Prepared by Atomic Layer Deposition for Metal Oxide Semiconductor Field Effect Transistor Applications

In this work, we investigated the influence of incorporating zirconia (ZrO2) in HfO2 gate dielectric on the electrical properties and reliability of n-channel metal oxide semiconductor field effect transistors (nMOSFETs). Detailed film physical, chemical and optical properties of Hf1-xZrxO2 as a function of Zr content were studied using high resolution transmission electron microscopy (HR-TEM), angle resolved X-ray photoelectron spectroscopy (AR-XPS), and spectroscopic ellipsometer (SE). Compared to HfO2, Hf1-xZrxO2 provides not only higher k values for further equivalent oxide thickness (EOT) scaling but also lower capacitance–voltage (C–V) hysteresis, lower threshold voltage (Vt) shift (ΔVt), and higher time-to-failure (TTF) lifetimes. Improved TTF lifetime of as high as three orders of magnitude and 35% lower Vt shift were achieved from the Hf1-xZrxO2 gate stack with x=0.8. The improved reliability of the Hf1-xZrxO2 gate dielectric is attributed to the reduced charge trapping in the Hf1-xZrxO2 gate dielectric caused by the ZrO2 incorporation.

The Effect of Polymeric Chain Extenders on Physical Properties of Thermoplastic Starch and Polylactic Acid Blends

The effects of a polymeric chain extender on the properties of bioplastic film made from blends of plasticized polylactic acid (p-PLA) and thermoplastic starch (TPS) were studied. Joncryl™ ADR 4370S, a polymeric chain extender, was blended with TPS and p-PLA at a level of 1% (w/w). A co-rotating twin-screw extrusion process was used to prepare films with various ratios of TPS and p-PLA. Mechanical and physical properties of films, including film tensile properties, surface energy, moisture content, hydrophilicity, moisture sorption behaviour and thermal mechanical properties were determined. During extrusion, films enhanced by 1% Joncryl addition demonstrated more desirable and consistent qualities, such as smoother film edge and surface. Addition of Joncryl significantly improved film tensile strength, 0.2% offset yield strength, and elongation, especially evident with the 250% elongation of 70/30 (TPS/p-PLA) film. Total surface energy of films was not significantly influenced by addition of Joncryl. However, the polar contribution to the total surface energy of 70/30 (TPS/p-PLA) film increased after the addition of Joncryl. The study showed that blending TPS with p-PLA transformed TPS film from being highly hydrophilic to highly hydrophobic. On the other hand, addition of Joncryl had limited effects on moisture content, water solubility, glass transition temperature and moisture sorption behaviour of TPS/p-PLA blend films.

Role of lignosulphonate in properties of fish gelatin films

A commercial low-gelling fish skin gelatin was used to prepare edible films by casting with glycerol and sorbitol added as plasticizers. In order to improve the extremely low water resistance of gelatin films, composite films were prepared with increasing concentrations (wt/wt) of lignosulphonate (LS) from eucalyptus wood (100:0, 85:15, 80:20, 75:25, 70:30 and 65:35, gelatin:LS). How gelatin film properties were affected by the different types of gelatin and LS was determined by comparing bovine gelatin and three different LS (Ca 2+, Mg 2+ and Na +) in a mixture ratio of 80:20. Physical properties of films were characterized in terms of tensile strength, elongation at break, water solubility, water vapour permeability and opacity. Dynamic oscillatory tests of film-forming solutions revealed strong LS interference with the cold-renaturation ability of gelatin. LS ratios equal to or higher than the 80:20 blend interfered with intermolecular aggregation of gelatin helices. Supposedly, LS acted as a filler, inducing mostly nonbonding interactions with gelatin, as deduced from Attenuated Total Reflectance Fourier Transform Infrared spectroscopy (ATR-FTIR) and Differential Scanning Calorimetry (DSC) studies. Lignosulphonate significantly reduced the elongation at break of fish gelatin films, water solubility being drastically reduced with a mixture ratio of 80:20 or higher. The water solubility of bovine gelatin–LS composite films was significantly lower than that for fish gelatin, regardless of the type of LS employed. For potential food packaging applications, the three LS were characterized in terms of cytotoxicity, radical scavenging capacity (DPPH assay) and antimicrobial capacity. The effective antioxidant levels (IC 50: 83.4–97.5 μg/mL) were noticeably lower than the cytotoxic ones (IC 50: 1480–1745 μg/mL), indicating that these compounds could be used as antioxidants at non-cytotoxic concentrations. No relationship between antioxidant and antimicrobial properties could be observed, the only notable antimicrobial finding being some activity against yeasts.