Physical Properties Of Films Research Articles

Control of Properties of Diamond-Like Silicon–Carbon Films

The possibilities of control of the electrophysical and mechanical properties of amorphous diamond-like silicon-carbon films by means of structural, chemical and structural-chemical modification are considered. The magnitude of the bias voltage and its frequency during the process of film synthesis, argon pressure in working chamber and precursors with different molecular structures are used as factors of structural modification. Introduction of transition metals with the concentration up to 30–35 at % into the film is used for chemical and structural-chemical modification. The high efficiency of control of the physical properties of films by the considered methods is shown.

Development of a novel active packaging film to retain quality and prolong the shelf life of fresh minced lamb meat

This research evaluated the effect of ploylactic acid (PLA) film containing nanochitosan (NCS) and Polylophium involucratum essential oil (PEO) on the chemical, microbial, and sensory characteristics of minced lamb during the 11-day refrigerated storage as well as characterization of the mechanical and physical properties of films. Films were developed by the solvent casting method and FTIR analysis of them showed the typical bands of PLA-based materials. NCS had no negative effect on tested mechanical parameters and PEO made films more flexible and improved the physical features of the PLA film. Based on the microbiological, chemical and sensory evaluations of the minced lamb, increasing the PEO concentrations in composite film improved oxidative stability, sensory properties of minced lamb, and also extended its shelf life in a positive manner comparing to the bare sample. In conclusion, development of active packaging with renewable materials could be an innovative approach in future packaging technologies. Practical applications Meat owing to high water content, pH, and availability of nutrients is extremely perishable. The current study revealed that the shelf life of lamb meat can be dramatically prolonged using PLA-based composite films containing nanochitosan and different concentrations of Polylophium involucratum essential oil. The composite films developed in our study are biodegradable, thus, can be an innovative approach in future packaging technologies.

Recent advances in the preparation, physical and functional properties, and applications of anthocyanins-based active and intelligent packaging films

Anthocyanins are natural colorants with excellent antioxidant, antimicrobial and pH-sensitive properties. In recent years, increasing attention has been paid to the development of active and intelligent packaging films based on biopolymers (e.g. polysaccharides and proteins) and anthocyanins from different plant sources. The structures of anthocyanins-rich films are characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffractometer. The physical properties of the films (e.g. color, thickness, moisture content, water solubility, barrier ability, mechanical properties and thermal stability) are influenced by anthocyanins. Moreover, anthocyanins-rich films exhibit excellent antioxidant, antimicrobial and pH-sensitive properties. In general, the structural, physical and functional properties of anthocyanins-rich films are closely related to the source, composition and content of anthocyanins, the type of biopolymers, and the film preparation and storage conditions. Till now, anthocyanins-rich films have been used to extend the shelf life of food (e.g. oil, cheese and fruits) and to monitor the freshness and quality of protein-rich food products (e.g. fish, shrimp, chicken, pork, milk and cheese). This review summarizes the recent advances in the preparation, structural characterization, physical and functional properties, and potential applications of anthocyanins-rich films in food smart packaging.

Improved physical and mechanical properties of food packaging films containing calcium hydroxide as a CO2 adsorbent by stearic acid addition

Abstract Stearic acid, SA (0, 1, 2, 3, 4 and 5%) was used to functionalize the surface of CO2-adsorbent powders to improve the physical and mechanical properties of active packaging LLDPE films. SA functionalization of calcium hydroxide/zeolite adsorbents was confirmed by the generation of a COO− symmetric stretching peak at 1404 cm-1 in Fourier transform infrared spectroscopy spectra. SA acted as a surfactant to reduce the agglomeration of the adsorbents in the film. Fewer aggregates resulted in improved tensile strength, reduced water vapor transmission rate, and increased light transmittance, which in turn improved the physical and mechanical properties of the films. When these films were used as packaging for kimchi, they did not affect the ripening of the kimchi, and showed excellent CO2 adsorption performance. When more than 2% SA was added to the adsorbent, the mechanical and physical properties of the film improved, and the carbon dioxide adsorption performance was good.

Effects of nisin concentration on properties of gelatin film‐forming solutions and their films

SummaryThe addition of nisin into a gelatin matrix can change properties of the film. The aim of this work was to develop gelatin‐based films containing different nisin concentrations in order to study their influence on the film's antimicrobial and physical properties and their rheological properties as a film‐forming solution (FFS). The FFS was characterised by rheological assays, and the gelatin‐based active films were characterised and assessed by the effects of nisin concentrations on their various properties, including antimicrobial activity. Nisin's concentration affected not only its viscoelastic properties of FFS but also its film solubility in water, film surface roughness and light barrier. The addition of nisin also slightly modified the water contact angle and the mechanical properties of the gelatin films. Finally, the films demonstrated activity against Staphylococcus aureus and Listeria monocytogenes at concentrations above 56 mg of nisin g−1 of gelatin.

Effect of Silane‐Based External Donor to Product Properties of Homopolypropylene Synthesized by Ziegler–Natta Catalyst

AbstractPolypropylene utilization has been rapidly growing since its discovery in 1954 due to its unique combination of mechanical and chemical properties. Most polypropylene manufacturer use MgCl2‐supported Ziegler–Natta catalyst comprises of MgCl2 support, internal donor, and active site of TiCl4. Addition of cocatalyst and external donor are also necessary in polymerization process. External donor, also known as selectivity control agent is often used in polypropylene production for stereo‐selectivity control as well as for product properties adjustment. The effect of two different silane‐based donor cyclohexylmethyldimethoxysilane (C‐Donor) and dicyclopentyldimethoxysilane (D‐Donor) on the product properties are studied. The impact is observed in homopolypropylene with similar melt flow rate synthesized with Ziegler–Natta catalyst. Product properties such as resin fundamental properties (xylene soluble, color), film physical properties (tensile strength, elongation), and film optical properties (clarity, haze, gloss) are observed and evaluated. From the series of testing, both C‐donor and D‐donor products perform comparable fundamental, physical, and optical properties. This study shows that the type of silane‐based external donor gives only slight effect to homopolypropylene product properties.

Metal-ion subplantation: A game changer for controlling nanostructure and phase formation during film growth by physical vapor deposition

Up until recently, thin film growth by magnetron sputtering relied on enhancing adatom mobility in the surface region by gas-ion irradiation to obtain dense layers at low deposition temperatures. However, an inherently low degree of ionization in the sputtered material flux during direct-current magnetron sputtering (DCMS), owing to relatively low plasma densities involved, prevented systematic exploration of the effects of metal-ion irradiation on the film nanostructure, phase content, and physical properties. Employing only gas-ion bombardment results in an inefficient energy and momentum transfer to the growing film surface. Also, for enhanced substrate biasing, the higher concentration of implanted noble gas atoms at interstitial lattice positions causes elevated compressive stress levels. High-power impulse magnetron sputtering (HiPIMS), however, provides controllable metal-ion ionization and, more importantly, enables the minimization of adverse gas-ion irradiation effects. The latter can be realized by the use of pulsed substrate bias applied synchronously with the metal-ion-rich portion of each HiPIMS pulse (metal-ion-synchronized HiPIMS), based on the results of time-resolved ion mass spectrometry analyses performed at the substrate position. In this way, both the metal-ion energy and the momentum can be precisely controlled for one to exploit the benefits of irradiation by metal-ions, which are also the film-forming species. Systematic studies performed in recent years using binary and ternary transition metal-based nitrides as model systems revealed new phenomena with accompanying unique and attractive film growth pathways. This Perspective paper focuses on the effects of low-mass metal-ion irradiation and their role for the nanostructure and phase control. We review basic findings and present original results from ion mass spectrometry studies and materials characterization for the effect of metal-ion subplantation. Key correlations are highlighted, which, if properly engaged, enable unprecedented control over film nanostructure and phase formation and, hence, the resulting properties. We show generalization from the findings to present a new concept for thin film growth in a hybrid HiPIMS/DCMS configuration with metal-ion-synchronized bias. Based on the results obtained for TM-based nitrides, there are no evident physical limitations preventing the extension of this deposition process concept for other materials systems or other metal–ion-based thin film growth techniques. Further exciting findings could, thus, be anticipated for the future.

Demineralized whey–gelatin composite films: Effects of composition on film formation, mechanical, and physical properties

AbstractIn this study, the objective was to prepare and characterize films with different concentrations of demineralized whey (3–10%) and gelatin (1–3%) containing glycerol (10–70%) as a plasticizer and chitosan or nanochitosan as an additive. Mechanical properties, thickness, grammage, opacity, moisture content, water, and ethanol solubilities of the obtained films were determined. The formation of films without glycerol and gelatin was not possible. A higher gelatin concentration led to more desirable mechanical properties. Thickness, grammage, opacity, and moisture content remained almost constant after increasing gelatin concentration. Heightening glycerol concentrations raised water and ethanol solubility. Despite presenting high water solubility, the films showed low ethanol solubility. The formulation containing whey (3%), glycerol (20%), gelatin (3%), and chitosan (0.1%) resulted in the highest performing film concerning physical and mechanical aspects. Through Fourier transform infrared spectroscopy analysis, it was possible to observe the displacement and the frequency reduction of the band near 3,300 cm−1, revealing different protein interactions. It indicates that hydrogen bonds occur between the amino group and OH of the protein molecules reducing film hydrophilicity. Contact angle measurements also showed a less hydrophilic character. The films present the potential to prolong the shelf life of food, such as dairy products.

Prolonging shelf life of chicken breast fillets by using plasma-improved chitosan/low density polyethylene bilayer film containing summer savory essential oil

Cold plasma assay was potentially useful persuade surface modification. In this study, antimicrobial properties of chitosan and low density polyethylene bilayer film with method cold plasma incorporated with summer savory essential oil (SEO) (1, 2 and 3%) for extending shelf life of chicken breast fillets was investigated. Moreover, mechanical and physical properties of film were assessed. Result showed that plasma treatment could improvement properties film and increase shelf life processing. After plasma treatment chitosan/polyethylene film containing 3% summer savory essential oil decreased water vapor permeability and oxygen transmission rate chitosan film. Addition of summer savory essential oil to the two-layer film, also improved tensile strength and elongation at break of film. The bilayer film with 3% of essential oil treatment cold plasma was chosen for microbial analysis during storage. All samples plasma-treated, films for this study included polyethylene (PE), bilayer of polyethylene and chitosan (PE/Ch) and Chitosan containing essential oil in direct contact (D) and gas phase (G). Result showed that shelf life of fillets were extended in direct contact and gas phase treatments to 13 days at refrigerator. It was 6 days for polyethylene and 8 days for Chitosan treatments. Essential oil incorporated film also decreased thiobarbitoric acid value of sample during storage. Cold plasma has a high potential in active packaging and food preservation.

Physical and antibacterial properties of corn distarch phosphate/carboxymethyl cellulose composite films containing tea polyphenol

Antibacterial packaging films were developed by incorporating tea polyphenol (TP) into corn distarch phosphate (CDP)/carboxymethyl cellulose (CMC) films via solvent casting. Incorporation of TP had a great influence on the physical properties of the composite films. The prepared composite films were evaluated by scanning electron microscopy and Fourier transform infrared spectroscopy, and their physical properties, moisture barrier properties, and antibacterial activities were investigated. Microstructural studies revealed that the surface of the CDP/CMC/TP composite films became rough and uneven sponge-like. Attenuated total reflectance Fourier transform infrared exhibited interactions between TP and CDP/CMC films matrix was caused by hydrogen bonding. Addition of TP into CDP/CMC films improved the extensibility, toughness, and moisture barrier properties of the composite films greatly. The CDP/CMC/TP composite films showed excellent antibacterial activity against Staphylococcus aureus, Bacillus subtilis, and Escherichia coli. The CDP/CMC/TP films are promising functional packaging materials. Practical applications Tea polyphenol (TP) exhibits effective antioxidant and antibacterial properties, which can be extracted from tea. In this work, we successfully fabricated a novel antibacterial films containing TP, and improved the physical properties of the films. This study can provide a good candidate and a promising way for the development of active packaging material in food industry. Moreover, there is immense potential in the application of food preservation.

Recent progress on the electronic structure, defect, and doping properties of Ga2O3

Gallium oxide (Ga2O3) is an emerging wide bandgap semiconductor that has attracted a large amount of interest due to its ultra-large bandgap of 4.8 eV, a high breakdown field of 8 MV/cm, and high thermal stability. These properties enable Ga2O3 a promising material for a large range of applications, such as high power electronic devices and solar-blind ultraviolet (UV) photodetectors. In the past few years, a significant process has been made for the growth of high-quality bulk crystals and thin films and device optimizations for power electronics and solar blind UV detection. However, many challenges remain, including the difficulty in p-type doping, a large density of unintentional electron carriers and defects/impurities, and issues with the device process (contact, dielectrics, and surface passivation), and so on. The purpose of this article is to provide a timely review on the fundamental understanding of the semiconductor physics and chemistry of Ga2O3 in terms of electronic band structures, optical properties, and chemistry of defects and impurity doping. Recent progress and perspectives on epitaxial thin film growth, chemical and physical properties of defects and impurities, p-type doping, and ternary alloys with In2O3 and Al2O3 will be discussed.

Water sorption thermodynamic behavior of whey protein isolate/ polyvinyl alcohol blends for food packaging

In food packaging systems, moisture content influences chemical and physical film properties, also determining processes such as food spoilage, and properties of food texture and crispiness level. The study of water permeation and sorption processes of new materials intended to be used as packaging is very important to determine the best application conditions and to predict the film behavior under different moisture conditions inside and/or outside the packaging. In order to determine the suitable temperature and water activity (aw) application conditions for whey protein isolate (WPI)/polyvinyl alcohol (PVOH) blends as food flexible packaging, water permeation and water sorption thermodynamic behavior of these materials were evaluated. WPI/PVOH films and blends had solubility preponderant over the diffusion on the water permeation process. Water sorption experimental data were well described by the GAB model, and curves showed a more expressive increase of water sorption at aw > 0.75, with lower equilibrium moistures (Ye) at room than at chilled temperatures. Differential enthalpy decreased and differential entropy increased by the Ye gain, and the occurrence of enthalpy-entropy compensation was confirmed with enthalpy driving the sorption process. The addition of PVOH to the WPI matrix made the water sorption process more spontaneous. Water sorption thermodynamic analysis indicates that the application of WPI/PVOH blends as packaging is best suitable for foods and external environments with aw below 0.75 and at room temperature.

Characterization of curcumin incorporated guar gum/orange oil antimicrobial emulsion films

Edible films are manufactured from natural, renewable, nontoxic, and biodegradable polymers and are safe alternatives to plastic food packaging. Despite ongoing research, biopolymer-based edible films still are not at a quality to ensure total commercial replacement of synthetic packaging materials. The study aims to compare the effectiveness of some novel methods employed to improve edible film properties. These include dispersion of orange oil (1% & 2% v/v) and/or curcumin into guar gum (GG), glycerol and lecithin-based edible films that are further reinforced with Sodium trimetaphosphate (STMP) crosslinking with the aim enhancing films physical properties. The films were characterized by measurement of film thickness, density, moisture content, water dissolvability, FTIR Spectroscopy, opacity, water vapor permeability, tensile properties, and antimicrobial activity. Orange oil and curcumin preserved their antimicrobial activity inside the films, which bestowed the films with an active packaging function. Control GG films had acceptable tensile and barrier properties that were further improved. All other film properties, such as opacity, dissolvability, and moisture content, that should be designed for specific application, were successfully modified with the methods used. Our results confirm successful application of STMP crosslinking, emulsion film formation, and active agent addition to edible films in manufacturing GG films for packaging.

Room Temperature Synthesized TiO2/Bi2Se3 Bilayer Thin Film by Simple Chemical Route: Study the Effect of Deposition Time of Bismuth Selenide on Physical Properties of Film

Room Temperature Synthesized TiO2/Bi2Se3 Bilayer Thin Film by Simple Chemical Route: Study the Effect of Deposition Time of Bismuth Selenide on Physical Properties of Film

Evaluation of Molecularly Imprinted Thin Films for Ephedrine Recognition

Ephedrine is an illicit drug, classified as precursor for methamphetamine, which is also used as stimulant, appetite suppressant, decongestant or asthma. In this study, novel molecularly imprinted polymer (MIP) films were prepared by sol-gel derived techniques, using N-(2-aminoethyl)-3-aminopropyltrimethoxysilane as functional monomer, to recognize ephedrine from aqueous solutions. The films were obtained by air-spraying the precursor solutions, with various concentrations of monomer and template, on glass supports. Infrared, thermogravimetry, ellipsometry, optic and atomic force microscopy analyzes of films provided information regarding the effect of molecular imprinting upon the physical properties of films. Further on, batch rebinding evaluation indicated that thinner films present high affinity for ephedrine, resulting in 6.2 imprinting factor after 15 minutes of contact, which attests the ability of the novel MIP films to recognize and rebind ephedrine.

Development and properties of new kojic acid and chitosan composite biodegradable films for active packaging materials

Chitosan and kojic acid composite films (CHn-KAm) utilizing three chitosan with differing molecular weights and kojic acid in different ratios were investigated. Results showed that chitosan with higher molecular weights presented higher viscosity, mechanical properties and lower water vapor permeability. Furthermore, kojic acid addition further significantly decreased apparent viscosity, water content, water vapor permeability as well as increasing the antibacterial activity of the films. Increasing the kojic acid concentration resulted in increased levels of a*, b*, ΔE*, opacity values and a decreased L* value, as compared to chitosan films. The mechanical properties of CHn-KAm films increased significantly with kojic acid addition into chitosan. FTIR spectral analyses revealed a strong interaction in the film matrix consistent with composite film mechanical and physical properties. The CHn-KAm films showed significant antibacterial effectiveness. The results suggested that the use of chitosan with a higher molecular weight as CHn-KAm films is expected to be a promising material for food packaging.

Physical Properties of Composite Films from Tilapia Skin Collagen with Pachyrhizus Starch and Rambutan Peel Phenolics.

Different composite films composed of tilapia skin collagen (TSC) with Pachyrhizus starch (PS) or rambutan peel phenolics (RPP) were prepared, and the physical properties of these films were determined. The effects of PS and RPP on TSC films were investigated, and our results indicated that PS and RPP could improve the physical properties of TSC films. Opacity and film thickness showed an enhanced trend with increasing PS and RPP contents in TSC films, whereas solubility in water, elongation-at-break (EAB), and water vapor permeability (WVP) showed declining trends. TSC film with 10% PS and 0.5% RPP had the highest tensile strength, and the tensile strength dropped drastically when the content of PS and RPP increased. The light transmittances of the films could decrease with the incorporation of PS and RPP. Differential scanning calorimetry (DSC) demonstrated that the addition of PS and RPP improved the thermal stability of TSC films. In addition, X-ray diffraction indicated that the crystallinity of the films decreased and the amorphous structure of the films tended to become more complex with the addition of PS and RPP. As shown by fourier transform infrared spectroscopy (FTIR) analysis, PS and RPP can strongly interact with TSC, resulting in a modification of its structure. Scanning electron microscope (SEM) analysis showed that there was a good compatibility between TSC, PS, and RPP. The results indicated that TSC film incorporated with 10% PS and 0.5% RPP was an effective method for improve the physical properties of the film. TSC–PS–RPP composite films can be used not only in biomedical applications, but also as active food packaging materials.

The Effect of Crospovidone on the Dissolution Profile of Amlodipine Besylate from Fast Orally Dissolving Film.

BACKGROUND:Fast Orally Dissolving Film preparation can be used for patients with problems in ingesting solid dosage forms, such as mentally ill, elderly, geriatric and patients who are reducing fluid intake or nausea.AIM:This study aimed to formulate and evaluate the rapid dissolution of amlodipine besylate.METHODS:Amlodipine besylate film was prepared by solvent casting method by using hydroxypropyl methylcellulose (HPMC) as film formers, crospovidone as superdisintegrant with Varian concentration F1 (2%), F2 (4%), F3 (6%) and F4 (8%), PEG 400 as plasticizer, sucralose and sorbitol as sweetener, citric acid as saliva stimulation, and grape essence as flavoring and coloring agent. Characteristics of films include organoleptic, weight uniformity, film thickness, surface pH, swelling, uniformity of content, time of disintegration, and dissolution.RESULTS:All formulated films produced a good film, smooth, transparent and uniform physical properties. F2 with polymer HPMC and the 4% concentration of crospovidone was the best formula with 31.50 seconds of disintegration time, the index expanding at the 15 second by 242.29% and the cumulative percent of the drug at 80 seconds by 98.08%.CONCLUSION:Amlodipine besylate can be formulated into fast orally dissolving film preparations using HPMC and crospovidone polymers so that they may be considered for use in the treatment of hypertension for patients with drug-induced problems in tablet or capsule form.

Impact of PLA/Mg films degradation on surface physical properties and biofilm survival

New biocompatible and bioabsorbable materials are currently being developed for bone regeneration. These serve as scaffolding for controlled drug release and prevent bacterial infections. Films of polylactic acid (PLA) polymers that are Mg-reinforced have demonstrated they have suitable properties and bioactive behavior for promoting the osseointegration process. However little attention has been paid to studying whether the degradation process can alter the adhesive physical properties of the biodegradable film and whether this can modify the biofilm formation capacity of pathogens. Moreover, considering that the concentration of Mg and other corrosion products may not be constant during the degradation process, the question that arises is whether these changes can have negative consequences in terms of the bacterial colonization of surfaces. Bacteria are able to react differently to the same compound, depending on its concentration in the medium and can even become stronger when threatened.In this context, physical surface parameters such as hydrophobicity, surface tension and zeta potential of PLA films reinforced with 10% Mg have been determined before and after degradation, as well as the biofilm formation capacity of Staphylococcus epidermidis.The addition of Mg to the films makes them less hydrophobic and the degradation also reduces the hydrophobicity and increases the negative charge of the surface, especially over long periods of time. Early biofilm formation at 8 h is consistent with the physical properties of the films, where we can observe a reduction in the bacterial biofilm formation. However, after 24 h of incubation, the biofilm formation increases significantly on the PLA/Mg films with respect to PLA control. The explosive release of Mg ions and other corrosion products within the first hours were not enough to prevent a greater biofilm formation after this initial time. Consequently, the Mg addition to the polymer matrix had a bacteriostatic effect but not a bactericidal one. Future works should aim to optimize the design and biofunctionality of these promising bioabsorbable composites for a degradation period suitable for the intended application.

Physical Properties of Oxide Films Formed by Plasma Anodization on Mg Alloy

In this work, we study physical and mechanical properties of oxide films formed on AZ91D magnesium alloy by plasma anodization at different temperatures. It is found that the higher the electrolyte temperature, the lower is the breakdown voltage of oxide layer. This is probably because films formed at higher temperatures are thinner and denser. Moreover, electrolyte temperature plays an important role in the physical properties of the films. As the electrolyte temperature increases from 20 to 50℃, the hardness of the oxide layer increases. Friction test against steel balls indicates that wear scars become narrower for films formed at higher temperatures because the films are harder, as indicated by the Vickers hardness. The thinner and denser nature of the oxide film formed at 50°C is also advantageous for heat transfer when film is used as a heat sink. Laser flash test results show very fast heat transfer for AZ91D with plasma anodized oxide layer formed at higher temperatures.