Physical Properties Of Films Research Articles

Effects of Glycerol Plasticizer on Physical Characteristic of Whey-Konjac Films Enriched with Clove Essential Oil

Background: Edible film is a food packaging that can be eaten directly and have protection function of outside contamination. The purpose of this research is to know how about the effect of using a glycerol plasticizer to film whey-konjac edible films that enriched with clove essential oil.
 Methods: A completely randomized design was used by different clove essential oil including P10, 0% clove essential oil; P10C1, 5% clove essential oil; P10C2, 10% clove essential oil; and P10C3, 15% clove essential oil. The present study investigated the physical characteristics, including tensile strength, elongation, Water Vapour Transmission Rate (WVTR), and microstructur film. Data were statistically evaluated using an Analysis of Variance (ANOVA) in Statistical Program for Social Science (SPSS) 16.0.
 Results: Results showed that the addition of glycerol plasticizer enriched with clove essential oil had no significant difference (p>0.05) to value of tensile strength, elongation, and WVTR of whey- konjac edible film. The value of tensile strength with the addition of clove essential oil at doses of 0, 5, 10, and 15% were 9.16, 7.9, 7.1, and 6.52 N, respectively. The concentration of 5% clove essential oil resulted in the best physical properties of film with a tensile strength 7.90 N, elongation 64.0%, and WVTR 8.12 g/mm2/day.
 Conclusion: Use of clove essential oil with different concentrations had no effect on tensile strength, elongation, and WVTR; but the addition of clove essential oil had promising potential to improve the physical characteristic of whey-konjac edible films.

Evaluation of physicomechanical properties of gluten-based film incorporated with Persian gum and Guar gum

This study aimed to optimize the formulation of gluten-based composite film incorporated with Persian gum and Guar gum using the response surface method. The effects of three variables gluten (37%wt), Persian gum (1–2%wt), and guar gum (1–2%wt) on the physicochemical properties of the films (thickness, color parameters (L*, ΔE, WI, YI), swelling, solubility, water vapor permeability (WVP) and mechanical properties of the film were investigated. The results confirmed that gluten is compatible with Persian gum and Guar gum. Optimization was determined, and then the morphological properties and interaction of the film components were investigated with SEM and FTIR, respectively. Results showed that all three variables significantly affected the films' mechanical and physical properties (P < 0.05). Increasing the number of gums in the film solution led to a decrease in the thickness of the films, and improved solubility and WVP of films. Moreover, the yellowness index of films raised with an increasing amount of gluten and Guar gum. Increasing the number of gums, Young's modulus and modulus of elasticity decreased significantly (P < 0.05). The optimum level of the variables with desirability of 0.992, obtained by the software, was 5 % gluten, 1.5 % Persian gum, and 1.5 % Guar gum (% w/w). Intensifying and shifting some absorption peaks of FTIR spectra pattern confirmed the interaction of gums and gluten chain functional groups. The current research outcomes demonstrated that proper interaction was established between gluten protein and gums and improved the physical properties of the films. High amounts of gum reduced the thickness of the film.

Nanoparticle size and surface chemistry effects on mechanical and physical properties of nano-reinforced polymers: The case of PVDF-Fe3O4 nano-composites

In the present work, PVDF - Fe3O4 nanoparticle (NP) nanocomposite films were produced using the electrospinning method. We investigated the effect of NP size on the film's morphology (fiber size), mechanical properties, and physical properties (β-phase percentage). Surprisingly, while nanoparticle size acts as an enhancer for mechanical properties, it appeared to act as an inhibitor in terms of its effects on the crystallization of the β-polymorph. This result seemed in discordance with many previous results. A focus on local interactions between the NP surface chemistry and PVDF chains revealed the influence of grafted ligands at the nanoparticle surface on the crystallization of the piezoelectric phase of PVDF. The results from the molecular dynamics (MD) simulations for systems of PVDF chains with slabs of –OH and oleic acid-grafted magnetite, showed that the probability of beta phase configuration decreases when the nanoparticles are functionalized with oleic acid and becomes more probable for –OH terminated magnetite. These computational results are in accordance with our experimental results. To verify this hypothesis, we prepared films with washed nanoparticles to eliminate the excess oleic acid that acts as a β-polymorph inhibitor. As a result, the amount of β-phase obtained for washed nanoparticles increased and the difference in the amount of β-phase between the different samples decreased. Moreover, when heated, the films of nanocomposite with washed NP developed more β-phase for smaller sizes of nanoparticles. At 140 °C, isomerization occurred, and oleic acid was converted into elaidic acid, reducing the steric hindrance, and promoting the interaction between PVDF chains and the surface of the nanoparticles. This isomerization reaction seems to be an enhancer of the α- to β-phase transition. Our results prove that optimizing multiple properties in nano-reinforced polymers requires consideration of different aspects, such as NP size, surface chemistry, and processing methods.Our results based on mixed experimental and modeling approach proved the usefulness of simulation in understanding and guiding our experimental results. Our results suggest that for enhancing piezoelectric properties in PVDF magnetite nano-composites, the chemistry and the molecular morphology of the grafted ligands when combined with NP size could lead to multi-properties enhancement simultaneously.

Impact of tea tree essential oil and citric acid/choline chloride on physical, structural and antibacterial properties of chitosan-based films

The purpose of this study was to develop a novel antimicrobial packaging film by using chitosan (CS), deep eutectic solvent (DES, a plasticizer) and tea tree essential oil (TTO, a natural antibacterial agent). The physical properties of the films (i.e., water content, solubility, water vapor permeability, color, thickness, water contact angle, and mechanical properties) demonstrated that TTO reduced the hydrophilicity of the films. At the same time, DES significantly improved the flexibility of the films. Micro-structural characterization showed that DES and TTO interacted with the CS matrix and were uniformly dispersed in films. The interactions among these main components in the films were verified by Fourier transform infrared spectroscopy and X-ray diffraction analysis. Thermogravimetric analysis further confirmed that these films had good thermal stability. In addition, the antibacterial assays verified that the CS-DES-TTO films could inhibit the activity of planktonic Sh. flexneri . The films prepared in this study showed the characteristics required of active packaging materials. • Chitosan, DES and TTO are uniformly distributed in the polymer matrix. • DES improved the mechanical properties of the film. • TTO improved the hydrophobicity of the film. • CS-DES-TTO films could damaged the cell membrane of Sh. flexneri.

Natural deep eutectic solvent of choline chloride with oxalic or ascorbic acids as efficient starch-based film plasticizers

Natural deep eutectic solvents (NADES) of choline chloride/oxalic acid (OA) and choline chloride/ascorbic acid (AA) were evaluated as innovative candidates for cassava starch-based film plasticizers, aiming to replace the glycerol standard. NADES-OA and NADES-AA were compared at five levels with a 40% glycerol standard. NADES were characterized by Fourier Transform Infrared (FTIR), and the films were subjected to optical, physical, and mechanical evaluations and structural analysis by X-ray Diffractometry (XRD) and FTIR. NADES-OA and NADES-AA improved the films' optical, physical, and mechanical properties, providing characteristics similar or superior to those plasticized with glycerol. NADES-OA showed a greater plasticizing effect, requiring a lower plasticizer concentration (30%) for the films to reach similar mechanical and physical characteristics to those with 40% glycerol. In addition, it presented a lower opacity and crystallinity index. Films with 60% NADES-AA had the highest elasticity and the lowest opacity but were highly water soluble and slightly yellow. Novel data reported here indicate that NADES-OA and NADES-AA can be used as efficient plasticizers for starch-based films, presenting vast potential for use as films or coatings for the agricultural and food industries.

Acceleration of Polybutylene Succinate Biodegradation by Terribacillus sp. JY49 Isolated from a Marine Environment.

Polybutylene succinate (PBS) is a bioplastic substitute for synthetic plastics that are made from petroleum-based products such as polyethylene and polypropylene. However, the biodegradation rate of PBS is still low and similar to that of polylactic acid (PLA). Moreover, our knowledge about degrader species is limited to a few fungi and mixed consortia. Here, to identify a bacterial degrader to accelerate PBS degradation, we screened and isolated Terribacillus sp. JY49, which showed significant degradability. In order to optimize solid and liquid culture conditions, the effect of factors such as temperature, additional carbon sources, and salt concentrations on degradation was confirmed. We observed a degradation yield of 22.3% after 7 days when adding 1% of glucose. Additionally, NaCl was added to liquid media, and degradation yield was decreased but PBS films were broken into pieces. Comparing the degree of PBS degradation during 10 days, the degradation yield was 31.4% after 10 days at 30 °C. Alteration of physical properties of films was analyzed by using scanning electron microscopy (SEM), gel permeation chromatography (GPC), and Fourier transform infrared (FT-IR). In addition, Terribacillus sp. JY49 showed clear zones on poly(butylene adipate-co-terephthalate) (PBAT), polycaprolactone (PCL), and copolymers such as P(3HB-co-3HV) and P(3HV-co-4HB), exhibiting a broad spectrum of degradation activities on bioplastics. However, there was no significant difference in absorbance when esterase activity was examined for different types of bioplastics. Overall, Terribacillus sp. JY49 is a potential bacterial strain that can degrade PBS and other bioplastics, and this is the first report of Terribacillus sp. as a bioplastic degrader.

Rheological and Film-Forming Properties of Chitosan Composites.

Chitosan (Chit) and its composite films are widely used in biomedical, cosmetic, and packaging applications. In addition, their properties can be improved and modified using various techniques. In this study, the effect of the type of clay in Chit composites on the structure, morphology, and physical properties of Chit solution and films was tested. The liquid flow properties of Chit solution with and without clay were carried out using the steady shear test. Chit films containing clay were obtained using the solution-casting method. The morphology, structure, and physical properties of the films were characterized by scanning electron microscopy, atomic force microscopy, infrared spectroscopy, swelling behavior, and tensile tests. The results reveal that for the Chit solution with clay (C1) containing 35 wt.% dimethyl dialkyl (C14–C18) amine, the apparent viscosity is the highest, whereas Chit solutions with other clays show reduced apparent viscosity. Rheological parameters of Chit composites were determined by the power law and Cross models, indicating shear-thinning behavior. Analytical data were compared, and show that the addition of clay is favorable to the formation of intermolecular interactions between Chit and clay, which improves in the properties of the studied composites.

Effect of Oxygen Flow Rate on PECVD Prepared ZnO Thin Films Physical Properties: Experiments Associated with DFT Calculations

Effect of Oxygen Flow Rate on PECVD Prepared ZnO Thin Films Physical Properties: Experiments Associated with DFT Calculations

Prediction of Serum Adsorption onto Polymer Brush Films by Machine Learning.

Using machine learning based on a random forest (RF) regression algorithm, we attempted to predict the amount of adsorbed serum protein on polymer brush films from the films' physicochemical information and the monomers' chemical structures constituting the films using a RF model. After the training of the RF model using the data of polymer brush films synthesized from five different types of monomers, the model became capable of predicting the amount of adsorbed protein from the chemical structure, physicochemical properties of monomer molecules, and structural parameters (density and thickness of the films). The analysis of the trained RF quantitatively provided the importance of each structural parameter and physicochemical properties of monomers toward serum protein adsorption (SPA). The ranking for the significance of the parameters agrees with our general understanding and perception. Based on the results, we discuss the correlation between brush film's physical properties (such as thickness and density) and SPA and attempt to provide a guideline for the design of antibiofouling polymer brush films.

Pectin Films with Recovered Sunflower Waxes Produced by Electrospraying.

Valorization of by-products obtained from food processing has achieved an important environmental impact. In this research, sunflower wax recovered from oil refining process was incorporated to low and high-methoxyl pectin films produced by electrospraying. Film-forming solutions and wax-added electrosprayed films were physical and structurally evaluated. The addition of sunflower wax to the film-forming solutions reduces conductivity while raising surface tension and density, whereas the type of pectin had a larger impact on viscosity, with the low-methoxyl solution having the highest value. These changes in physical solution properties influenced the film characteristics, observing thicker films with lower water vapor transmission rate (WVTR) when adding wax. Micrographs obtained by scanning electron microscopy (SEM) revealed the presence of wax particles as small spherical shapes, having a good distribution through the sectional area of films. According to X-ray diffraction (XRD), atomic force microscopy (AFM) and mechanical properties analyses, the presence of wax had an impact on the degree of crystallinity, producing a more amorphous and rougher film’s structure, without affecting the elongation percentage and the tensile stress (p>0.05). These results showed that wax addition improves the physical properties of films, while the suitability of using both pectins and the electrospraying technique was demonstrated.

Guar gum propionate-kojic acid films for Escherichia coli biofilm disruption and simultaneous inhibition of planktonic growth

Nosocomial bacterial infections associated with biofilms inspire to explore newer bactericidal strategy with eco-friendly biomaterials as sustainable alternatives. In this research work, we successfully developed bio-safe films from kojic acid(KA) and guar gum propionate(GGP) for Escherichia coli biofilm disruption and planktonic cell killing. High DS(degree of substitution = 1.52) GGP was synthesized from guar gum (GG)assisted by chaotropic ions at room-temperature. Biopolymers were routinely characterized in CHN analyzer, FT-IR, TGA and XRD analysis. KA loaded GGP films were prepared by cross-linking the molecules in presence of epichlorhydrin and two different percentages of KA were employed. Film physical and tensile properties were systematically evaluated and optimized. Water vapour permeability (WVP) and tensile strength of final film GGPFK10 were recorded at 0.741 ± 0.09gmm−1kPa−1h−1 and 19.23 MPa. KA release from GGP matrix followed controlled diffusion process. MIC of GGP was 130 μg/mL and zone of inhibition of GGPFK10 was confirmed at 16.1 mm. SEM experiments disclosed the absence of pili-like structures with squeezed and elongated cellular morphology in dead planktonic cells. Disruption of biofilms was experimented in detail by CV assay, fluorescent, light microscopic and SEM studies. The film showed excellent cell-viability on human adult dermal fibroblast (HADF)cell-line. Overall, the biosafe film would be a potent antibacterial device for treating infections against E.coli biofilms and planktonic cells.

Effects of X-Rays, Electron Beam, and Gamma Irradiation on Chemical and Physical Properties of EVA Multilayer Films

Gamma-ray irradiation, using the cobalt-60 isotope, is the most common radiation modality used for medical device and biopharmaceutical products sterilization. Although X-ray and electron-beam (e-beam) sterilization technologies are mature and have been in use for decades, impediments remain to switching to these sterilization modalities because of lack of data on the resulting radiation effects for the associated polymers, as well as a lack of education for manufacturers and regulators on the viability of these sterilization alternatives. For this study, the compatibility of ethylene vinyl acetate (EVA) multilayer films with different ionizing radiation sterilization (X-ray, e-beam, and gamma irradiation) is determined by measuring chemical and physical film properties using high performance liquid chromatography, differential scanning calorimetry, Fourier-Transform InfraRed spectroscopy (FTIR), surface energy measurement, and electron spin resonance techniques. The results indicate that the three irradiation modalities induce no differences in thermal properties in the investigated dose range. Gamma and X-Ray irradiations generate the same level of reactive species in the EVA multilayer film, whereas e-beam generates a reduced quantity of reactive species.

Tuning the physical and functional properties of whey protein edible films: Effect of pH and inclusion of antioxidants from spent coffee grounds

This study presents a food waste valorization scheme targeting to the production of novel whey protein edible films. Initially, the effect of pH of whey protein on the physical properties of films was studied. Whey protein edible films were subsequently supplemented by an antioxidant-rich extract derived from spent coffee grounds targeting to improve the functional properties of films. The results showed significant changes at different pH, indicating that, depending on the intended application, films' properties can be controlled by shifting pH of whey protein solution. Inclusion of antioxidants resulted in edible films with UV-light resistance properties, whereas the mechanical properties and in particular tensile strength and elastic (Young's) modulus were increased. Water vapor permeability of films was considerably increased by the inclusion of antioxidants, compared to control films. Additionally, whey films enriched with phenolic compounds from spent coffee grounds presented high antioxidant activity (73.2%), which was decreased only 16.8% after a 12-month storage period. The proposed valorization scheme resulted in the development of edible films with tailor-made properties conforming with the pillars of Circular Economy.

Bandgap tuning, high electrical conductivity, and room-temperature ferromagnetism in La- and V-doped SrSnO3 epitaxial films

In this study, La- and V-doped SrSnO3 epitaxial films were fabricated via pulsed laser deposition, and the effects of doping on the structure and physical properties of films were systematically investigated. Detailed x-ray diffraction characterization demonstrates that the lattice parameters of V-doped SrSnO3 (SrSn1−xVxO3, x = 0–1, SSVO) films decrease gradually as the V content increases. The optical bandgap first increases from 4.43 to 4.56 eV and then decreases to 3.31 eV with the increasing V content. Density functional theory calculations indicate that the strong hybridization between Sn 5s and V 3d orbitals causes an initial expansion of the bandgap. Doping SSVO films with 5% La greatly improves the electrical conductivity. Hall-effect measurements show that the (La0.05Sr0.95)VO3 film has the lowest room-temperature resistivity of 0.05 mΩ cm and correspondingly the largest carrier density of 1.79 × 1022 cm−3. Ferromagnetism in SrSn1−xVxO3 films is highly dependent on V concentration at room-temperature, and the origin of ferromagnetism may be explained by the bound magnetic polaron model.

Rheological properties of wood/bacterial cellulose and chitin nano-hydrogels as a function of concentration and their nano-films properties.

In this study, rheological properties of the Wood Cellulose NanoFibers (WCNF), Bacterial Cellulose NanoFibers (BCNF), and Chitin NanoFibers (ChNF) as well as physical properties of films prepared from each nano‐hydrogel were investigated. Each nano‐hydrogel was prepared in 2 concentrations of 0.5 and 1 wt% for rheological study. Rheological properties were measured using a rotational rheometer. The flow behaviour data were fitted with rheological models. Apparent viscosity was higher in higher concentrations of nano‐hydrogels. Herschel‐Bulkley model was the best model for flow behaviour data fitting. BCNF nano‐hydrogels had the highest hysteresis loop while WCNF nano‐hydrogels had the best structure recovery and lowest hysteresis loop. At LVE (Linear Viscoelastic Region), G′ (storage modulus) and G″ (loss modulus) had a constant value, but as strain increased their values decreased. Storage modulus was found to be greater than loss modulus in all samples during frequency sweep test. BCNF nano‐hydrogel showed the lowest frequency dependency. Chitin nanofilms had the highest elongation and stress value.

Studies of the correlations between physical properties and complex permeability of NiFe thin films

We investigated the physical properties of Ni81Fe19 thin films intended for use in inductors operating at high frequencies. With a variety of characterization techniques, we measured saturation magnetization, anisotropy field, resistivity, and complex permeability of sputtered films with thicknesses in the range of 16–910 nm. We correlated the physical properties of the films with their complex permeability. Our analysis indicates that films under 100 nm have the characteristics most suitable for use in inductor structures. Such films would exhibit high permeability, allow inductors to operate at high frequencies and, at the same time, minimize eddy current losses.

Theoretical Analysis of Tubular Film Extrusion and its Applications for HMW-HDPE

Abstract Theoretical analysis of the tubular film extrusion using computer simulation presented has been used to preduct bubble shapes, velocity profiles and stretching stresses. From the theoretical analysis, maximum stretching stresses, which are closely related to film physical properties, were predicted under various process conditions. This theoretical analysis was applied to high molecular weight HDPE tubular film process. It was found that high strength HDPE film can be produced by maintaining high stretching stress, which is obtained on the conditions of high out-put rate, high take-up speed and low temperature by reducing the heat generated by viscous dissipation. Further, the processability of HDPE film produced using bubble stabilizing equipment was discussed.

Development of edible films from protein of brewer's spent grain: Effect of pH and protein concentration on physical, mechanical and barrier properties of films

Brewer's spent grain (BSG) is the protein-rich agro-industrial waste generated from breweries. In this study, the protein extracted from BSG was used in the development of edible film. BSG protein films plasticized with glycerol were developed at varying pH and protein concentrations. The effect of pH and protein concentration on the physical properties of films were studied. Film's properties were significantly affected by pH and protein concentration. High pH favors the increase in the protein film's solubility, with increased tensile strength, elongation at break, and puncture strength. The tensile strength of the films was in the range of 0.71 to 1.44 MPa. The film's solubility increased by increasing pH, whereas swelling capacity, water activity, and water vapor permeability (WVP) decreased. Increased concentrations of protein in films resulted in enhanced moisture content, mechanical properties, and water activity. The transparency values of films were increased by increasing pH and decreased by increasing the protein concentration.

Sustainable Bioactive Packaging Based on Thermoplastic Starch and Microalgae.

This study combines the use of corn starch and Tetradesmus obliquus microalgae for the production of antioxidant starch films as flexible packaging material. Starch was plasticized with glycerol and blended with 1 w% polyallylamine chosen as an agent to modify the film physical properties. The addition of polyallylamine improved film water stability and water vapor transmission rate as well as mechanical stiffness and tenacity. The dried Tetradesmus obliquus microalgae, which showed an EC50 value of 2.8 mg/mg DPPH (2.2-Diphenyl-1-picrylhydrazyl radical), was then used as antioxidant filler. The addition of microalgae provided the films with good antioxidant activity, which increased with microalgae content increasing. To our knowledge, this is the first study reporting the development of sustainable bioactive packaging films composed of almost 100% starch, and follows the European union’s goals on plastics strategy concerning the promotion of bio-based, compostable plastics and the setting up of approaches to prevent food waste with a simple plastic packaging.

Pectin-based active packaging: A critical review on preparation, physical properties and novel application in food preservation

Owing to increasing environmental concerns and growing demands for food quality maintenance, biodegradable active packaging is emerging on the market to overcome the challenges faced by traditional plastic packaging. Pectin, with characteristics of low price, non-toxic and good polymerization, is an ideal material for active food packaging. This review offers the current state of studies on pectin-based active packaging. Three different film formation methods were critically summarized. Physical properties of pectin-based packaging were systemically characterized regarding various pectin structural conformation. Furthermore, preservation behaviors and related mechanisms were fully illustrated to exhibit the outstanding advantages of pectin-based active packaging in food preservation. Pectin-based active packaging can be developed in either wet or dry processes. Wet process contains casting method leading to compact surface morphology and spraying method requiring specialized equipment, while dry process mainly refers to extrusion method with higher efficiency and meets the needs at commercial production. Physical properties of packaging including mechanical, hydrophobic and thermal characteristics are enhanced by modification of pectin conformation or incorporation with bio-polymers, overcoming the weaknesses of pure pectin packaging, such as thermal instability and strong hydrophilicity. After being functionalized with active compounds, pectin-based packaging with great antimicrobial, antioxidant and barrier properties is quite suitable for food preservation. Pectin-based packaging has great advantages to extend shelf-life of food by retarding lipid oxidation, inhibiting microbial growth, controlling water movement, etc. As a result, pectin-based active packaging with great physical and functional properties, has promising prospects in food preservation. • The main methods of pectin packaging preparation are casting, spraying and extrusion. • Film physical and functional properties are modified by incorporating other polymers. • Pectin active packaging can maintain quality and extend shelf-life of packaged food. • Pectin conformation exerts influences on film properties and preservation behaviors. • Pectin-based active packaging has a promising prospect in food packaging industry.