Physical Properties Of Films Research Articles

Effect some Factors on the Structural Properties of the CdS Thin Films Prepared by Chemical Bath Deposition

CdS thin films were prepared by chemical bath deposition technique (CBD) onto the glass substrates at different conditions of preparation. The obtained samples are studied by X-Ray diffraction (XRD). The XRD patterns of CdS samples revealed the formation with a hexagonal crystal structure P36mc, and the clear effect of the concentration of thiourea, cadmium sulfide, NaOH, time and temperature deposition, and annealing temperature, on the structure of the prepared thin films. through the study, we found that the samples have preferred orientation along [002], also the thickness of thin films decrease with deposition time after certain value, with the appearance of free cadmium. It has been found that the 200°C is the best temperature for annealing to improve the other structural and physical properties of films.

Effect some Factors on the Structural Properties of the CdS Thin Films Prepared by Chemical Bath Deposition

CdS thin films were prepared by chemical bath deposition technique (CBD) onto the glass substrates at different conditions of preparation. The obtained samples are studied by X-Ray diffraction (XRD). The XRD patterns of CdS samples revealed the formation with a hexagonal crystal structure P36mc, and the clear effect of the concentration of thiourea, cadmium sulfide, NaOH, time and temperature deposition, and annealing temperature, on the structure of the prepared thin films. through the study, we found that the samples have preferred orientation along [002], also the thickness of thin films decrease with deposition time after certain value, with the appearance of free cadmium. It has been found that the 200°C is the best temperature for annealing to improve the other structural and physical properties of films.

Incorporation of commercially-derived antimicrobials into gelatin-based films and assessment of their antimicrobial activity and impact on physical film properties

Four antimicrobials, namely; Articoat DLP 02 (AR), Artemix Consa 152/NL (AX), Auranta FV (AFV) and sodium octanoate (SO) were examined for their effectiveness, both before and after heat treatments, against bacterial strains Bacillus cereus, Pseudomonas fluorescens, Escherichia coli, Staphylococcus aureus and the microflora obtained from commercial beef steaks. Minimum inhibitory concentrations (MIC) using AR, AX, AFV and SO against these microbes were then obtained using the 96-well plate method. SO was the most effective against all bacterial strains, demonstrating the lowest MIC compared to the other antimicrobials. These antimicrobials were then successively incorporated into beef-derived gelatine films and these films were subsequently tested for structural, mechanical and barrier properties. Significantly (p < 0.05) enhanced water vapour barrier properties were determined only for antimicrobial films containing AX or SO when compared to control films. On the basis of FTIR spectra, significant changes in the structure of SO-containing films were determined when compared with control gelatin films. It was shown that active antimicrobial agents could potentially serve as commercial antimicrobial coatings for application onto conventional plastic-based food packaging.

Chalcogenide Thin Films Prepared using Chemical Bath Deposition Method: Review

The aim of this study is to discuss the synthesis of thin films using chemical bath deposition method. In recent years, studies of thin films of different groups have attracted great attention due to their applications are possible in many areas of modern technology. Researchers have deposited binary, ternary and quaternary thin films from aqueous solutions using chemical bath deposition method. Here, the growth of metal sulfide, selenide and telluride thin films has been reported. The influence of deposition parameters on the physical properties of films was investigated. The research findings indicate that an increase in deposition time allows more materials to be deposited onto the substrate. Morphological studies of films show that the films thicknesses were increased as the bath temperature was increased.

Effect of type of encapsulating agent on physical properties of edible films based on alginate and thyme oil

Active edible coatings incorporating antimicrobial agents such as thyme oil are studied to improve the shelf-life of fresh foods. The type of encapsulating agents used to microencapsulate the active compound could affect both, emulsions and film's physical properties. The aim was to study the effect of different encapsulating agents (trehalose, β-cyclodextrin and Tween 20) on physical and antimicrobial properties of alginate/thyme oil emulsions and films. Physical and antimicrobial characterization of film-forming emulsion and films were developed. Results showed differences in rheological behavior, particle size and stability of emulsions by encapsulating type. The highest stability of emulsions containing Tween 20 (instability of 0.69%) was attributed to more interactions between components (observed by FTIR) and the lowest particle size, but other samples also showed high stability (instability <5%). The stability of emulsions did not correlate with films microstructure indicating that interactions amount components changed when solvent was evaporated. Films containing trehalose and β-cyclodextrin had less color and opacity than Tween 20, which is an advantage by industrial applications by coating due cannot affect the organoleptic characteristics of a fresh product. In conclusion, it is important the choice of encapsulating agent in order to use for developing active coatings with potential for applications in fresh food.

Effect of processing conditions on the optical properties of films based on alginate, caseinate and lemongrass oil

Edible films incorporating active agents allow for increases in the shelf life of food products. The aim was to evaluate the film forming suspensions (FFSs) stability on the physical properties of films based on alginate and lemongrass oil. Sodium caseinate (NaCas) concentration (0.15–0.75% w/w) was modified at pH (4–8) and stirring rate (5000–10,000 rpm), measuring stability and droplet size, while physical characterizations (color, solubility) were determined for films. Stability increased with the increase of NaCas concentration and a decrease in droplet size. The instability by creaming was mainly observed in basic pH. Addition of NaCas and lemongrass oil affected the color (ΔE00 > 12) and opacity (>12%), obtaining yellow films. Optimal conditions were NaCas concentration 0.15%w/w, pH 8.0, stirring speed of 7500 rpm, where droplet size, opacity, ΔE00 and solubility factor were 7.08 µm, 15.64%, 12.25 and 86.23%, respectively. In conclusion, pH and NaCas concentration altered FFS stability, but physical characteristics were not affected, except for the resultant yellow color.

Hybrid co-deposition of mixed-valent molybdenum–germanium oxides (MoxGeyOz): A route to tunable optical transmission

Mixed-valent oxides of molybdenum and germanium were deposited simultaneously using reactive magnetron co-deposition within an oxygen–argon environment. The films' stoichiometry, optical, and physical properties were varied through changes in oxygen partial pressure induced by systematic variation of the potential applied to the molybdenum cathode. The oxygen partial pressure was determined from the drop in pressure as measured by a capacitance manometer, assuming constant argon partial pressure. To facilitate deposition, a constant power of 100W DC was applied to the germanium cathode, while power was applied to the molybdenum target using a modulated pulse power supply. Modulated pulse power magnetron sputtering was used due to its ability to generate high target power densities, allowing for rapid reduction of oxygen on the surface of the “oxygen poisoned” molybdenum cathode, as well as for its highly metallic plasma resulting in increased oxygen-gettering capability. Changes in the modulated pulse power supply's capacitor bank voltage load, stepped from settings of 300 to 380V, resulted in films ranging from mixtures of transparent GeO2 (Ge4+) and MoO3 (Mo6+) to the introduction of various absorptive ionic species including Mo5+, Mo4+, Ge2+ and Ge0, as determined from X-ray photoelectron spectroscopy. The presence of each of the aforementioned ions results in characteristic changes in the films' band energies and optical absorption. As deposited MoxGeyOz thin films grown using this method have been shown to have optical gap energies that are able to be tailored between 3.57eV and 0.18eV, spanning useful ranges for devices operating in the visible and near-infrared.

The influence of annealing temperature on some physical properties of spray deposited nanostructured CdS thin films

Absract. In this study, the effect of annealing temperature on physical properties of CdS thin films was studied. CdS in the form of thin film was prepared by a simple and inexpensive spray pyrolysis technique for various annealing temperatures. After deposition, films were annealed at 400-450-500 °C for 2 hours at air atmosphere. The effects of the annealing temperature on the physical properties of the films were investigated by studying the transmittance measurements, spectroscopic ellipsometry technique, atomic force microscope (AFM) observations and the four probe technique. The transmittance measurements were used to estimate the band gap energy by the linear fit of ( a h n ) 2 curve. The band gap energy was found to be slightly decreasing with the annealing process. From the four probe measurement the resistivity was determined and found to be strongly decreasing with increasing the annealing temperature. Finally, annealing process and annealing temperature confirmed significant effects on the optical, electrical and surface properties CdS thin films.

Preparation of iron cobaltite thin films by RF magnetron sputtering

Iron cobaltite thin films with spinel structure have been elaborated by radio-frequency (RF) magnetron sputtering from a Co1.75Fe1.25O4 target. Influence of argon pressure on structure, microstructure and physical properties of films has been examined. Iron–cobalt oxide thin films essentially consist of one spinel phase when deposited at low pressure (0.5 and 1.0Pa). At high pressure (2.0Pa), the global stoichiometry of the film is changed which results in the precipitation of a mixed monoxide of cobalt and iron beside the spinel phase. This in-situ reduction due to an oxygen loss occurring mainly at high deposition pressure has been revealed by X-ray diffraction and Raman spectroscopy. Microstructural evolution of thin film with argon pressure has been shown by microscopic observations (AFM and SEM). The evolution of magnetic and electrical properties, versus argon pressure, has been also studied by SQUID and 4 point probe measurements.

Effect of hsian-tsao gum (HG) content upon rheological properties of film-forming solutions (FFS) and physical properties of soy protein/hsian-tsao gum films

The effect of hsian-tsao gum (HG) content upon both rheological properties of soy protein/hsian-tsao gum film-forming solutions (FFS) and physical properties of films was studied. It was verified that the HG content significantly affected the viscoelastic properties of FFS. Lower HG content (≤30%) decreased apparent viscosity, elastic modulus (G′) and viscous modulus (G″) of FFS. However, blending of higher HG content (>30%) showed a reverse trend. Moreover, the results indicated that the addition of lower content (≤30%) HG to the soy protein isolate (SPI) films provided blend films with better mechanical properties, less sensitive to moisture and stronger barrier properties against water than pure SPI film. The analysis of nuclear magnetic resonance (NMR) revealed the addition of HG significantly changed the water state of SPI films. In particular, the free water ratio of blend films compared with pure SPI films significantly decreased. It implied that intermolecular interaction between SPI and HG resulted in the increase of hydrophobic interaction of films. Fourier transformation infrared (FTIR) data and SEM photographs indicated Maillard reactions occurred between SPI and HG, giving rise to a more compact structure than SPI films.

Vacuum thermal evaporation of polyaniline doped with camphor sulfonic acid

Intrinsically conducting polymers belong to a class of organic polymers with intriguing electronic and physical properties specifically for electro-optical applications. Significant interest into doped polyaniline (PAni) can be attributed to its high conductivity and environmental stability. Poor dissolution in most solvents has thus far hindered the successful integration of PAni into commercial applications, which in turn, has led to the investigations of various deposition and acidic doping methods. Physical vapor deposition methods, including D.C. magnetron sputtering and vacuum thermal evaporation, have shown exceptional control over physical film properties (thickness and morphology). However, resulting films are less conductive than films deposited by conventional methods (i.e., spin and drop casting) due to interruption of the hyperconjugation of polymer chains. Specifically, vacuum thermal evaporation requires a postdoping process, which results in incorporation of impurities and oxidation of surface moieties. In this contribution, thermally evaporated films, sequentially doped by vacuum evaporation of an organic acid (camphorsulfonic acid, CSA) is explored. Spectroscopic evidence confirms the successful doping of PAni with CSA while physical characterization (atomic force microscopy) suggests films retain good morphology and are not damaged by the doping process. The procedure presented herein also combines other postpreparation methods in an attempt to improve conductivity and/or substrate adhesion.

Effect of Poly (Butyl Acrylate) and Poly (Ethylene Oxide) Modified Sago Starch on Natural Rubber Latex Films Physical Properties

Sago starch is modified with 1 wt % Poly butyl acrylate (PBA) and Poly ethylene oxide (PEO) monomer and 1 wt% of initiator, potassium persulfate (PPS) at temperature 80°C for 2 hours. Modified sago starch is cooled under room temperature for 24 hours prior to Natural Rubber Latex (NRL) compounding process. Results indicates that NRL films with PBA modified sago starch have higher mechanical properties compared to PEO modified sago starch and unmodified sago starch. Swelling test indicates that PEO gives lowest percentage of swelling and crosslink density. This is due to higher reaction probability that produce more closely packed structure with NRL matrix compared to PBA which only improved the compatibility of sago starch particle with rubber matrix. Thus, chemically modified sago starches are preferable to be used as fillers to produce better interaction between fillers and rubber matrix.

Acetate cellulose film with bacteriophages for potential antimicrobial use in food packaging

The search for new technologies that guarantee the safety and quality of food has intensified, as has concern for consumer health, leading to the adoption of measures to reduce food-related risks. The purpose of the study was to evaluate the efficiency of active biodegradable films incorporated with bacteriophage for future application in packaging materials. Cellulose acetate films incorporated with solution of bacteriophages showed antimicrobial activity against Salmonella Typhimurium ATCC 14028 displayed the formation of inhibition zones in Muller-Hinton agar, and a growth curve, using the diffusion method in liquid medium. There was an increase in the lag phase and slower growth of microorganisms in the environment containing bacteriophages with the films, compared to control. The mechanical and physical properties of films, such as thickness, elongation and puncture resistance showed no significant effects. However, tensile resistance was different between control and treatments. The addition of bacteriophage altered the film surface, as observed by atomic force microscopy. There was a higher porosity of the films containing the bacteriophage solution compared to control. The acetate films may be incorporated with bacteriophages, since the physical and mechanical properties of the films were not changed drastically and there was an effect of the antimicrobial film.

Growth of Ultrathin Iron Oxide Films on Ag(100)

Ultrathin iron oxide films are useful model materials for fundamental studies of surface processes and exhibit intriguing properties as catalysts, as demonstrated recently in a number of studies utilizing platinum as a substrate. We report a study of the initial stages of iron oxide film growth on an Ag(100) surface using scanning tunneling microscopy, low energy electron diffraction, X-ray photoelectron spectroscopy, and near-edge X-ray absorption fine structure spectroscopy, with the goal of elucidating the effects of the substrate material on FeOx film growth and physical properties. We demonstrate that a well-ordered, monolayer-thick FeO(111) film can be prepared which is similar to the well-studied structure formed on Pt(111), though with a significantly expanded lattice constant indicative of smaller Fe–O buckling and weaker interactions with the substrate. Increased oxygen pressure during deposition leads to formation of a multilayer phase taking the form of well-ordered islands. Although superficially similar to FeO(111), spectroscopic measurements show a substantial proportion of Fe3+ in the phase. FeO(100) grains are observed upon deposition at elevated substrate temperatures, which is proposed to result from formation and oxidation of iron clusters embedded in the surface.

Physical properties of emulsion-based hydroxypropyl methylcellulose/whey protein isolate (HPMC/WPI) edible films

The objective of this research was to study the effect of the film microstructure of oil-in-water emulsions stabilized by hydroxypropyl methyl cellulose/whey protein isolate (HPMC/WPI) with or without sodium dodecyl sulfate (SDS) over physical properties of HPMC/WPI emulsion-based films. The films were prepared with different HPMC/WPI-oil-SDS combinations (%w/w for 100g of dispersion): HPMC; WPI; HPMC/1WPI-0.5-SDS; HPMC/1WPI-1; HPMC/2WPI-0.5; HPMC/2WPI-1-SDS. Physical properties of films were evaluated. The results showed no statistical differences (p>0.05) between the thicknesses of EFs (0.156±0.004mm). The effect of oil content and incorporation of SDS showed the inverse trend for WI and ΔE, the increasing order of change, for WI and ΔE, among the formulation evaluated was: HPMC/1WPI-1>HPMC/2WPI-0.5>HPMC/2WPI-1.0-SDS≈HPMC/1WPI-0.5-SDS≈WPI>HPMC for WI and HPMC/1WPI-0.5-SDS>HPMC/2WPI-1.0-SDS>HPMC/2WPI-0.5>HPMC/1WPI-1 for ΔE, respectively. The addition of oil and SDS decreased the TS and EB, because oil addition into EF induces the development of structural discontinuities, producing an EF with less chain mobility, and consequently, with less flexibility and resistance to fracture.

Formulation and Evaluation of Mucoadhesive Buccal Films of Diclofenac Potassium

The development of mucoadhesive buccal films has increased dramatically over the past decade because it is a promising delivery alternative to various therapeutic classes of peptides, vaccines and nanoparticles. The present investigation highlights the formulation and evaluation of muco adhesive buccal films of Diclofenac Potassium. The mucoadhesive buccal films were prepared by solvent casting technique using polymers like Hydroxy Propyl Methyl Cellulose K4M, Ethyl cellulose and Carbopol 934P. The formulated films were evaluated for their physical parameters like surface area, folding endurance, swelling studies, drug content and In vitro release studies. The films of different formulations were found to have good physical appearance, surface area, optimum swelling capacity and drug release. In vitro drug release studies in pH 6.6 phosphate buffer showed a prolonged release for over five hours for all formulations. Formulation F1 containing HPMC K4M and Carbopol 934P was selected as best formulation. Therefore it can be concluded that the polymers and their combination influenced the physical properties of film and their release characteristics.

Numerical investigation of ammonia falling film absorption outside vertical tube with nanofluids

Abstract In the last years the ammonia-water refrigeration cycle has been gradually improved by using nanofluid technology. In this work, a numerical model for the absorption of ammonia on a falling film was developed for different ammonia-water mixtures containing nanoparticles and dispersants. The variation of both falling film thickness and physical properties of the mixture were considered to find the best fitting model. Results show that when absorption pressure decreases or when initial concentration of mixture increases, the relative intensity of effect on absorption rate is weakened by the variation of thermal conductivity but enhanced by the variation of mass transfer coefficients and flow resistance, while the variation of mixture’s viscosity exhibits very low effect. When the results are compared to similar experimental data for the ammonia falling film absorption with nanofluids, it was found that the heat and mass transfer are mainly affected by the film drag reduction and its physical properties. The numerical model obtained can be used for calculating the absorption rate of ammonia-water-nanofluid mixtures with acceptable accuracy, since 87% of relative errors are lower than 20%.

Effect of Sprayed Solution Flow Rate on the Physical Properties of Anatase TiO2 Thin Films

Titanium dioxide (TiO2) thin films were synthesized on glass substrates by spray pyrolysis. The effect of solution flow rate on the physical properties of the films was investigated by use of x-ray diffraction (XRD), scanning electron microscopy, atomic force microscopy (AFM), and spectrophotometry techniques. XRD analysis revealed the tetragonal anatase phase of TiO2 with highly preferred (101) orientation. AFM images showed that grain size on top of TiO2 thin films depended on solution flow rate. An indirect band gap energy of 3.46 eV was determined by means of transmission and reflection measurements. The envelope method, based on the optical transmission spectrum, was used to determine film thickness and optical constants, for example real and imaginary parts of the dielectric constant, refractive index, and extinction coefficient. Ultraviolet and visible photoluminescence emission peaks were observed at room temperature. These peaks were attributed to the intrinsic emission and to the surface defect states, respectively.

Protein extracted from castor bean (Ricinus communis L.) cake in high pH results in films with improved physical properties

Castor bean plant (Ricinus communis L.) is a very important crop worldwide because it can be produced under severe climate conditions. Also, it gained importance last year because of the increasing industrial demand of biodiesel. The objective of this study was to study the effect of the pH (10, 11 and 12) of extraction of proteins from castor bean cake on some physical properties of films based on these proteins modified by tannin. Increasing pH improved the protein extraction yield without affecting their amino acid profile. The films prepared using these proteins by casting process showed a structural matrix sufficiently cohesive, intense total color difference (ΔE*=83–85) and relatively high opacity (8–15%). The values of tensile strength, elongation at break, Young Modulus, water vapor permeability and hydrophobicity of films were affected by the protein extraction pH. The protein extraction in pH=12 resulted in more rigid, more resistant, with enhanced extensibility, a lower rate of water diffusion and less hydrophilic films. The films showed homogeneous surfaces and dense internal microstructure. FT-IR spectra of all films showed characteristic bands and peaks typical of proteins with no differences in positions and intensity due to pH variations. It is possible to produce films from proteins extracted from castor bean cake by casting process. These films may be used in agriculture, specifically for planting seedlings.

Improving the Structural, Optical and Electrical Properties of ITO Nano-Layered Thin Films by Gas Flow Argon

Indium tin oxide (ITO) thin films of 150 nm thickness were deposited on quartz glass substrates by RF sputtering technique, followed by thermal annealing treatment. In this technique, the samples have been annealed at different temperature, 300OC, 400OC, 500OC respectively in Argon gas flow. Structural and surface morphological properties were analyzed by X-ray diffraction (XRD) and Atomic Force Microscopy (AFM) after annealing. The XRD showed a polycrystalline structure of ITO film with maximum peak intensity at 2θ= 30.54, &lt;222&gt; orientation without any change in the cubic structure. Continuous and homogeneous films obtained by the AFM after annealing treatment. The visible spectrum from the spectrophotometer showed high transparency between 81% and 95% in the. Increasing the annealing temperature yields evenly distributed pyramidal peaks shaped particles with low roughness. Resistance of ITO thin film was significantly improved from 8.75 kΩ to 1.96 kΩ after 10 minute from 300OC to 500OC annealing temperatures respectively under Argon gas flow. ITO films physical properties would be well improved by this method which is highly suitable for cost effective photonic devices.