Decrease In Light Transmission Research Articles

Stretchable and translucent liquid-metal composite mesh for multifunctional electromagnetic shielding/sensing and Joule heating

Flexible liquid metal (LM)-based composite materials with strain-undiminished electromagnetic interference (EMI) shielding effectiveness (SE) and multifunctional integration are attracting great attention due to the urgent need for flexible electronic and wearable devices. Herein, stretchable and translucent polydimethylsiloxane/LM composite mesh (PLM) is developed by introducing highly deformable LM filler into elastomer and constructing conductive mesh structures by cast molding and mechanical sintering, which shows strain-enhanced EMI SE without a significant decrease in light transmittance due to the contribution of stretch-induced enhanced conductivity, mesh densification, and orientation. The linear response of relative SE change with tensile strain allows the PLM to exhibit ideal EM sensing characteristics, superior to most reported stretchable EMI shields. The oriented mesh structure endows the stretched PLM with anisotropic EMI SE under rotation, revealing a feasible means to realize tunable SE in a tensile state. More importantly, the high conductivity and deformability of the LM network further provide the PLM with excellent and relatively stable Joule-heating performance when served as a stretchable Joule heater. This work offers a new strategy for developing multifunctional stretchable LM-based composites that can achieve strain-enhanced EMI SE and ideal EM sensing capability without significantly sacrificing the light transmittance and Joule-heating performances under stretching.

Development of novel carboxymethyl cellulose/gelatin-based edible films with pomegranate peel extract as antibacterial/antioxidant agents for beef preservation

Novel antioxidant and antibacterial composite films were fabricated by incorporating pomegranate peel extract (PPE) into gelatin and carboxymethyl cellulose matrices. Increasing PPE concentration significantly (p < 0.05) altered physical properties and improved UV (decrease in light transmission 87.30 % to 9.89 % at 400 nm) and water resistance, while FTIR and molecular docking results revealed hydrogen bonding between PPE and film matrix. PPE incorporation enhanced antioxidant activity up to 84.15 ± 0.12 % and also restricted gram-positive and gram-negative bacterial growth by 72.4 % and 65.9 % respectively after 24 h, measured by antimicrobial absorption assays. For beef packaging applications at refrigeration temperatures, PPE films were most effective at extending shelf-life up to 3 days, as evidenced by reduced total viable counts, total volatile basic nitrogen, weight loss, and pH changes compared to control films. Therefore, these antioxidant and antibacterial films have potential applications in food packaging to protect against mechanical stress, light exposure, microbial spoilage, and oxidative free radicals.

Measuring of Alpha-1 Antitrypsin Concentration by Nephelometry or Turbidimetry.

Most clinical laboratories quantify alpha-1 antitrypsin using either nephelometry or turbidimetry techniques because they are commercially available, amenable to automation, and precise. Both methods are based on light scatter. The foundation of both techniques is based on incubation of the specimen with anti-AAT polyclonal antibody solution, a polymer matrix between endogenous AAT and the reagent antibodies forms, leading to production of light-scattering large particles. Although these two terms are sometimes used synonymously, technically speaking they are not.Nephelometry measures the amount of turbidity or cloudiness of a solution by directly quantifying the intensity of the light scattered by insoluble particles in the sample. Therefore, this technique measures the light that passes through the sample, with the detector being placed at an angle from the sample. Turbidimetry is the process of measuring the loss of intensity of the light transmitted linearly through a sample caused by the scattering effect of insoluble particles. The decrease in light transmission is measured compared to a reference, and the absorbed light is quantified.Beyond specific technical differences between both techniques, there are two major differences between the two procedures that may influence the results. First, the concentration of the sample and the resulting intensity of scattered light relative to the intensity of the light source is one major factor. Second, the size of the scattering particles is also a key differentiating factor. This chapter describes the technical requirements, the different protocols, and the clinical applicability of these two techniques in the diagnosis of alpha-1 antitrypsin deficiency.

Unveiling the effect of molecular weight of vanillic acid grafted chitosan hydrogel films on physical, antioxidant, and antimicrobial properties for application in food packaging

Till now, a wide range of chitosan (CHS)-based food packaging films have been developed. Yet, the role of molecular weight (MW), which is an important physical property of CHS, in determining the physicochemical and biochemical properties of vanillic acid (VA)-grafted CHS hydrogel films synthesized using CHS with different MWs has not been investigated until now. Three kinds of CHS including low, medium, and high MWs were grafted separately with VA through a carbodiimide mediated coupling reaction. No significant difference in water resistance properties was observed with increasing MW of CHS, in contrast to obvious decrease in light transmittance and opacity. The VA-g-CHS hydrogel films exhibited significantly improved light blocking capacity. A significant improvement in antioxidant (~6-fold) and antimicrobial (~1.2-fold) activity was observed after grafting with VA. In contrast, the free radical scavenging and antimicrobial activity decreased with increasing MW of CHS. Most importantly, VA-g-CHS hydrogel films could maintain the freshness of cherry tomatoes for up to 10 days at ~25 °C. However, no significant difference was observed depending on the MW value of CHS. This pioneering work is of great importance in guiding the selection of MW of CHS biomacromolecule to design hydrogel films with desired physicochemical and biochemical properties.

Development of robust polyvinylidene fluoride (PVDF)-based self-clean coating for commercial solar cells/panels employing spray method

This study involved the creation of self-cleaning surfaces on glass substrates by applying a polyvinylidene fluoride (PVDF) solution through spray coating. The properties of the coated surfaces were evaluated using various methods, including contact angle, Scanning Electron Microscopy, Atomic Force Microscopy, and UV–Vis spectroscopy analyses. The findings indicate that the characteristics of the coated surfaces were influenced by the concentration of the PVDF solution. As the concentration increased, the contact angle also increased while the transmittance decreased. A contact angle of 101° was attained as the maximum at a PVDF solution concentration of 5%. Furthermore, the light transmittance through coated substrates exhibited consistent levels up to the 5% PVDF concentration. However, a substantial decrease in light transmittance was observed beyond this 5% PVDF concentration threshold. The stability of the self-cleaning coating was assessed by subjecting the samples to UV-light for a duration of 288 h.

Stainability of Acrylic Intraocular Lens With Brilliant Blue G: An In Vitro Study

To evaluate the stainability of several acrylic intraocular lens (IOLs) with Brilliant Blue G (BBG) in vitro. Clinically relevant, laboratory, experimental study. LS313MF15 as a hydrophilic acrylic IOL and X-70, W60R, CP2.2R, YP2.2R, XC1, and XY1 as hydrophobic acrylic IOLs were included in this study. Prepared acrylic IOLs were evaluated for staining via immersion for different periods in BBG solution with adjusted concentrations. In cases where IOLs were stained blue, the sustained release of BBG and IOL cross-sectional images were evaluated, as well as changes in the optical properties of the IOLs via spectrophotometry. All acrylic IOLs were stained with BBG in a BBG concentration- and staining time-dependent manner, with almost no sustained release of BBG observed. Lenses with a higher water content exhibited more pronounced staining, and BBG penetrated into the IOLs. A decrease in light transmittance with a peak wavelength of 610 to 620 nm was observed in blue-stained IOLs. LS313MF15 was markedly blue stained even with a short period of staining. Any acrylic IOL can be stained with BBG, but hydrophilic IOLs are particularly susceptible to blue staining. Precautions should be taken in surgeries requiring the use of BBG staining, and efforts should be made to ensure that BBG components are sufficiently washed out intraoperatively.

A Scoping Review on the Polymerization of Resin-Matrix Cements Used in Restorative Dentistry.

In dentistry, clinicians mainly use dual-cured or light-cured resin-matrix cements to achieve a proper polymerization of the organic matrix leading to enhanced physical properties of the cement. However, several parameters can affect the polymerization of resin-matrix cements. The main aim of the present study was to perform a scoping review on the degree of conversion (DC) of the organic matrix, the polymerization, and the light transmittance of different resin-matrix cements used in dentistry. A search was performed on PubMed using a combination of the following key terms: degree of conversion, resin cements, light transmittance, polymerization, light curing, and thickness. Articles in the English language published up to November 2022 were selected. The selected studies' results demonstrated that restorative structures with a thickness higher than 1.5 mm decrease the light irradiance towards the resin-matrix cement. A decrease in light transmission provides a low energy absorption through the resin cement leading to a low DC percentage. On the other hand, the highest DC percentages, ranging between 55 and 75%, have been reported for dual-cured resin-matrix cements, although the polymerization mode and exposure time also influence the DC of monomers. Thus, the polymerization of resin-matrix cements can be optimized taking into account different parameters of light-curing, such as adequate light distance, irradiance, exposure time, equipment, and wavelength. Then, optimum physical properties are achieved that provide a long-term clinical performance of the cemented restorative materials.

Proton irradiation induced damage effects in CH&lt;sub&gt;3&lt;/sub&gt;NH&lt;sub&gt;3&lt;/sub&gt;PbI&lt;sub&gt;3&lt;/sub&gt;-based perovskite solar cells

Perovskite solar cells (PSCs) have a great potential for space applications due to their high specific power, low cost and high defect tolerance. PSCs used in space will be subjected to high-energy particle irradiation, especially proton irradiation, resulting in the decline of photovoltaic (PV) performance. However, the research on proton irradiation effects in PSCs is still in its infancy stage. In this work, the CH&lt;sub&gt;3&lt;/sub&gt;NH&lt;sub&gt;3&lt;/sub&gt;PbI&lt;sub&gt;3&lt;/sub&gt; (MAPbI&lt;sub&gt;3&lt;/sub&gt;) thin films and their PSCs are irradiated by protons with energy of 0.1, 2, 10, 20 MeV, etc. Irradiation-induced changes in PV parameters of the PSCs are studied as a function of proton fluence. The structural and surface morphological changes of the irradiated MAPbI&lt;sub&gt;3&lt;/sub&gt; films and Au electrode layers of PSCs are characterized by X-ray diffraction and scanning electron microscopy. In addition, UV spectrophotometer is also employed to analyze the transmission loss in glass substrate induced by proton irradiation. It is found that PSCs exhibit superior resistance against proton irradiation. The PV properties of the PSCs don’t degrade after 0.1 MeV (2 MeV) proton irradiation up to a fluence of 1×10&lt;sup&gt;13&lt;/sup&gt; p/cm&lt;sup&gt;2&lt;/sup&gt; (1×10&lt;sup&gt;14&lt;/sup&gt; p/cm&lt;sup&gt;2&lt;/sup&gt;). The irradiation-induced damage in the charge transport layers may be the main cause for the performance degradation of PSCs. The gaseous products (NH&lt;sub&gt;3&lt;/sub&gt; and CH&lt;sub&gt;3&lt;/sub&gt;I) of perovskite decomposition eventually lead to exfoliation of the top Au electrode from the PSCs. Regarding 10 and 20 MeV proton irradiation with larger projected ion ranges, the irradiations create color center defects in glass substrate of PSCs, which results in a decrease in light transmission of visible spectrum. However, the color center defects, specifically non-bridging oxygen hole centers, will be partly annealed at room temperature or 100 ℃, reducing the transmission loss in glass. The reported results may help predict the performance degradation of PSCs in space irradiation environment.

Bioactive Edible Sodium Alginate Films Incorporated with Tannic Acid as Antimicrobial and Antioxidative Food Packaging.

Currently, biodegradable and functional food packaging materials have attracted more and more attention due to their potential advantages. Biopolymers are one of the promising materials used to produce biodegradable food packaging films, and sodium alginate (SA) is one of the most used polysaccharides. In this work, we explored a novel edible sodium alginate (SA)/tannic acid (TA) film as biodegradable active food packaging material. The impact of TA concentration on the UV light blocking ability, transparency, water vapor barrier ability, mechanical strength, antioxidant, and antimicrobial activity of the SA-TA films was comprehensively investigated. Fourier transform infrared spectroscopy results revealed that strong hydrogen bonding was the main intermolecular interaction between SA and TA. As TA concentration in the films increased, the water vapor permeability (WVP) decreased from 1.24 × 10−6 to 0.54 × 10−6 g/m/h/Pa, the DPPH radical scavenging activity increased from 0.008% to 89.02%. Moreover, the incorporation of TA effectively blocked UV light and elevated antimicrobial activity against Escherichia coli. Overall, the SA films with TA exhibited better water vapor barrier ability, remarkable UV-light barrier ability and antioxidant activity while showing a slight decrease in light transmittance. These results indicated the potential application of TA as a functional additive agent for developing multifunctional food packaging materials.

Experimental study for the reproduction of particulate matter deposition on greenhouse plastic films

Atmospheric particulate concentrations have been increasing due to secondary particle emissions and climate change. The resulting particulate matter (PM) deposition may decrease the amount of sunlight reaching crops in greenhouses by reducing the light transmittance (LT) performance of the covering film. To determine the cause of this decrease in LT, indoor and outdoor experiments were performed. The indoor experiment comprised exposure to various PM and deposition types (i.e., wet and dry conditions), while the outdoor experiment comprised exposure to a natural environment while testing different film installation methods. These results showed that the decrease in LT through greenhouse films was related to PM conditions. Wet deposition of the ion component of PM caused a greater drop in LT than dry deposition . Additionally, the installation film angle, exposure period, and rainfall exposure of the greenhouse-covering material all significantly affected LT. The decreased LT in the indoor PM-generation experiment was similar to when films were exposed to natural conditions for more than 12 months. These results could assist the farmers in predicting covering materials LT decrease caused by PM and in strategically managing the plastic films of their greenhouses. • The effect of PM on light transmittance (LT) degradation in greenhouses was studied. • Rainfall washes away the deposited particulate matter and helps to restore LT. • The wet deposition of ion components significantly decreased the LT of film. • The outdoor LT decrease was analysed for installation angle, duration, and rainfall. • Decrease in LT in the indoor experiment was similar to that under natural conditions.

In situ one‐step fabrication of layered double hydroxide deposited on cellulose: Effect of modified cellulose on physical properties of polyurethane composites

AbstractThe article reports the fabrication of cellulose‐layered double hydroxide (LDH) obtained by urea hydrolysis method. A wide characterization was carried out to assess the morphological, spectroscopic and barrier properties of LDH modified cellulose. The cellulose‐LDH was then used as hybrid reinforcement in polyurethane (PU) composites. A slight improvement in thermal stability of PU was achieved and a better hydrophilicity was obtained, due to the intrinsic polarity of LDH. Elastic modulus of PU composites increased up to 48 MPa for a filler loading of 10% wt. Finally, UV barrier properties were studied in the range 280–700 nm. The produced composite showed a noticeable decrease in light transmission as the reinforcement content increase, displaying high light‐blocking properties with a quasi‐total resistance to transmission in UV range.

The antifungal effect against Penicillium italicum and characterization of fruit coating from chitosan/ZnO nanoparticle/Indonesian sandalwood essential oil composites

The properties of an antifungal coating film made from chitosan (CH) combined with zinc oxide nanoparticles (ZNPs) and Indonesian sandalwood essential oil (SEO) were investigated. Incorporation of 0.5% SEO or 0.025% ZNPs plus 0.5% SEO into 0.8% CH coating solution showed outstanding effects on the inhibition of both mycelium growth and spore germination of Penicillium italicum. The antifungal mechanism was explained by measuring the loss of membrane integrity of spores. The antifungal effectiveness was confirmed in vivo by carrying out tests on tangerine fruit. The biocompatibility of these coatings was analyzed using Fourier transform infrared spectroscopy, scanning electron microscopy, atomic force microscopy, and fluorescence microscopy. Significant increases in pH, appearance viscosity, and transparency and a decrease in light transmittance were found with 0.8% CH plus 0.025% ZNPs and 0.5% SEO compared with the control. CH films incorporating SEO and ZNPs can be used as an edible film and coating to reduce chemical use.

A DFT study on the electronic structure, magnetic and optical properties of Er doped ZnO: Effect of Er concentration and native defects

We report on first-principles study of the effect of Er concentration and intrinsic defects (VO and VZn) on the electronic structure and optical properties of Er-doped ZnO using the GGA + U method. The lattice constants and band gap of ZnO calculated in this work are in agreement with experimental values. The results showed that the band gap of Er-doped ZnO decreases with increasing Er concentration, while it increases with the presence of O or Zn vacancies. Furthermore, the existence of VO causes the formation of a deep donor level in the band gap. Er–ZnO + VZn is a degenerate p-type semiconductor, and shallow acceptor states are created near the Fermi level. The magnetic moment of doped ZnO increases and Er 4f electrons are responsible for the induced magnetic moments. The absorption coefficient enhances in the visible range in Er doped ZnO. In the Er–ZnO + VO model, both absorption and reflection are relatively enhanced in the visible range, leading to a decrease in light transmittance. Hence, the magneto-optoelectronic properties of ZnO could be improved by an optimal concentration of Er as well as with the presence of oxygen vacancies.

Investigation on the piezo-ceramic discoloration during the DC electrical degradation process

The electrical degradation of piezoelectric ceramics occurs during the working process, whose features are the decrease in resistance, the increase in leakage current, and the formation of discoloration areas. During the process of electrical degradation, many times, the occurrence of electrical breakdown events leads to the production and growth of discoloration areas. In this paper, the high-voltage impact test of piezoelectric ceramics is carried out and the obtained discoloration areas are compared with the electrical degradation discoloration areas. It is found that the discoloration areas produced by the high-voltage impact test are the same as those obtained by the electrical degradation test, which shows that the grain arrangement is disordered and the grain boundary is fuzzy. The phase structure of the discoloration areas obtained by the two methods is consistent with that of the piezoelectric ceramic matrix, and it has been discovered that the formation of discoloration areas in the process of electrical degradation is a physical change process. The formation of discoloration areas is caused by the change in the local structure of piezoelectric ceramics, which leads to a decrease in light transmittance, and it is a direct cause. The formation of these discoloration areas will lead to a reduction in dielectric loss but has no effect on the piezoelectric constant, capacitance, and Curie temperature. The resistance of the ceramic sample decreases with the increase in load voltage.

Determining the spectral transmittance of photochromic contact lenses

PurposeThis study evaluates the spectral transmission of photochromic contact lenses. MethodA custom built photochromic filter transmission testing device (ICS photochromic bench) was developed to measure the spectral transmission of light adaptive filters. The spectral properties of seven contact lenses were measured using the ICS photochromic bench at 23⁰C and 35⁰C in their exposed (darkening) state at time points 0 s, 45 s, 90 s, and 15 min. and their unexposed (fading) state at 45 s, 15 min. and 20 min.. Mixed between and within repeated measures ANOVA (MRM-ANOVAs) and generalized additive modeling (GAMs) were used to compare the effects of temperature and solar exposure time on spectral transmittance of photochromic contact lenses. ResultsThe mean (±SD) transmission of photochromic contact lenses in the exposed state were 94.7 ± 0.2, 39.1 ± 1.4, 27.0 ± 0.7 and 14.7 ± 1.0, and 93.7 ± 0.9, 38.8 ± 2.4, 30.2 ± 1.8, and 26.1 ± 1.0 at times 0 s, 45 s, 90 s, and 15 min. at 23⁰C and 35⁰C respectively. The mean (±SD) transmission of photochromic contact lenses in the unexposed state were 18.3 ± 1.5, 71.3 ± 2.4, and 80.2 ± 2.4, and 39.1 ± 1.0, 90.6 ± 1.0 and 91.1 ± 0.9 at times 45 s, 15 min. and 20 min. at 23⁰C and 35⁰C respectively. There was a significant decrease in light transmission as solar exposure time increased (GAM, MRM-ANOVA, p < 0.05). There was a significant effect of temperature and solar exposure time on the photochromic contact lenses (GAM, MRM-ANOVA, p < 0.05). The differences in the light transmitted by the photochromic contact lenses occurred at time 90 s and 15 min (Tukey HSD, at 90 s and 15 min, p < 0.05), where contact lenses at a temperature of 35⁰C showed greater light transmission than that at 23⁰C. There were differences in spectral transmittance based on the temperature of the contact lens. Contact lenses at 35⁰C transmitted more light than at 23⁰C at all unexposed times (MRM-ANOVA, p < 0.05). ConclusionSpectral transmission of photochromic contact lenses were successfully measured with the ICS photochromic bench. Temperature appears to influence both the activation and deactivation of photochromic contact lenses such that the higher the temperature, the greater the light transmission.

Robust and sustainable starch ester nanocomposite films for packaging applications

This paper reports the use of cellulose nanocrystals (CNCs) and nanoclays as reinforcing fillers in starch ester (StE) films. The StE was prepared by a one-step homogenous esterification reaction to obtain a degree of substituted hydroxyl moieties of 2.8. StE films with varying concentrations (0, 0.5 wt.%, 1.5 wt.%, 3 wt.%, and 5 wt.%) of CNC and nanoclay were then fabricated using a solvent casting process and characterized using scanning electron microscopy, optical spectrometry, water absorbance, water vapor permeability, mechanical tests, and simulated compostability studies. The SEM images for the CNC-filled composites revealed aggregates of CNC in the matrix, while nanoclay showed a homogeneous dispersion. Although no apparent visible change in transparency was observed for all filled films, a decrease in light transmission was revealed by optical density measurements. The incorporation of the nanofillers improved the yield strength of the starch-ester films significantly. This improvement in the tensile strength was as much as 112 % and 173 % for 5 wt. % of CNC and 5 wt.% of nanoclay, respectively. No hydrolysis was observed for StE under the simulated composting conditions over six months. Compared to the unfilled StE films, the reinforced films showed a reduction in weight approximately equal to the amount of the filler, with a maximum degradation of 8.9 wt.% for the 5 wt. % nanoclay filled StE films.

Flexible ZnO Nanoparticle-Poly(methyl methacrylate) Hybrid Films and Their Ultraviolet Shielding Behaviors

Flexible hybrid films are finding increasing applications in functional devices. In this work, transparent ZnO nanoparticle and poly(methyl methacrylate) (PMMA) hybrid films are made for ultraviolet (UV) shielding with significantly higher ZnO contents than what has been reported. The tensile strength increases with the ZnO nanoparticle volume percent, from ~ 10 MPa for the pure PMMA samples to ~ 24 MPa for the 20 vol.% ZnO samples, a 150% increase. The elongation at break also increases with the ZnO content increase until 10 vol.% (a 67% increase), after which the elongation at break stays constant. All the ZnO-PMMA films show UV absorption at ~ 365 nm wavelength, with an increasing degree for higher ZnO content samples and a corresponding light transmittance decrease at longer wavelengths. Long-term UV irradiation leads to a reduction in tensile strength and elongation at break, along with lower UV shielding performance. This work proposes that the optimal ZnO content is 5–10 vol.% for the overall UV shielding performance while maintaining good mechanical properties.

Justification of selection of packaging material and packing method for preservation of vitamin-mineral concentrate quality

In the production of quality food products, special attention must be paid to its packaging and storage. These process steps are especially important for products containing labile biologically active substances. In order to select packaging materials and packing method, an analysis of the scientific literature was conducted with the search query “packaging materials for foodstuffs” and “the effect of packaging on the preservation of vitamins during food storage” in the Google Scholar system. The article presents trends in the development and use of packaging materials, reflects the advantages and disadvantages of biopolymers, as well as prospects for improving the characteristics of packaging materials. As an example, for the choice of packaging material and packing method, data from Russian scientists based on packaging materials used in the Russian Federation is given. Storage of beef steaks in bags with reduced gas permeability under vacuum and a modified gas atmosphere with a reduced content of free space for 14 days contributes to the inhibition of bacteria. Storage of sterilized and ultra-pasteurized milk is preferably in bags of a three-word film filled with titanium dioxide, in comparison with glass packaging, due to a decrease in light transmission and a decrease in the rate of decomposition of vitamin C. It is preferable to store orange juice in packages of combined materials that exclude the presence of an air cushion, which positively affects the content of vitamin C. Based on the analysis of packaging materials used in the food industry and taking into account the humidity and chemical composition of the vitamin and mineral concentrate, it seems appropriate to use packaging materials made of polymer films with high light and gas impermeability, which can reduce the rate of destruction of vitamin C and other easily oxidized components and eliminate the use of ? -radiation, replacing it by evacuation. The use of edible films for vitamin and mineral concentrate as packaging materials remains open and requires more careful study.

Cu-doped ZnS coatings for optoelectronics with enhanced protection for UV radiations

Molecular dopants are of great importance in nano-chemical compounds by improving the function of inorganic electronic devices. In this article, Cu:ZnS (CZS) powders were made using the chemical method. Thin films were deposited by the physical method. The CZS films showed cubic crystal structures with a single hexagonal peak. The impact of an increase in Cu2+ dopants was investigated not only in reducing the grain size but also in reducing the optical energy gap and deviation parameters of the lattice constants. The estimated energy gaps of CZS nanostructures (NSs) were (3.70, 3.66, 3.0, and 3.76 eV) for Cu dopant (0, 1.5, 3.0, and 4.5 at.%); an indication of a blueshift. Redshift was also noticed for Cu dopant 4.5% due to interstitial sites. Moreover, the transmittance for all specimens was (70–95%) in the visible and near IR-region and reduced in the UV range (< 400 nm). The decrease in light transmittance occurred in the UV range when the Cu2+ concentration increased. Besides, the study revealed a reduction in the power loss of the thin film indicating high quality and a highly optimized electrical and electronic system. The Neural Network was utilized to obtain validation of results by the theoretical study.

Preparation and physicochemical characterization of films prepared with salmon skin gelatin extracted by a trypsin-aided process

The recovery of gelatins from Atlantic salmon (Salmo salar) skin for film formation and characterization was studied. Fish skins pre-treated with trypsin (250 U/g) produced the highest hydroxyproline content (7.41 ± 0.49 mg hydroxyproline/g treated skin) and yield (53.05 ± 4.38%) of gelatin, as compared to the use of saline solution. Pre-treatment with a lower concentration of trypsin (1 U/g) at a shorter pre-treatment time successfully reduced the degradation of gelatin with co-production of high molecular weight α-chains. Gelatin was further extracted by a trypsin-aided process for film formation and characterization. Films with increasing protein concentration (from 1 to 5%, w/v) exhibited higher thickness, tensile strength, and elongation at break (EAB), but a marked decrease in EAB for films with 6 and 7% (w/v). Films with 5% proteins showed higher thickness, lower tensile strength and higher EAB with increasing concentrations of glycerol (from 10 to 50% of proteins, w/w). All films exhibited high water uptake, decrease in light transmission and an increase in opacity as the protein and glycerol contents increased. Electrophoretic studies showed that the increase in the mechanical properties of the films was correlated with the increase in protein concentration, owing to the increased content of high molecular weight chain fractions. Furthermore, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) revealed the interaction between the proteins and glycerol for all films. This study demonstrated the viability of the trypsin supplementation process to obtain salmon skin gelatin for film formation.