Film Tensile Research Articles

Synthesis of MnO@Fe2O3 core-shell doped PVA/PVP polymeric nanocomposites for electronic and optoelectronic devices: Mechanical, electrical, and optical properties

Abstract The aqueous solution cast method was utilized to create biodegradable nanocomposite of polymers (PNC) films from a poly (vinyl alcohol) / poly (vinyl pyrrolidone) blend (70/30 wt%) and MnO@Fe2O3 nFs. The dislocation density, particle size, and interplanar distance were all calculated. The PNC films' surface shape changes from smooth to porous and somewhat rough because of the nanosized MnO@Fe2O3 particles' dispersion in the blend matrix, which diminishes the blended crystallites' size. The composite film's tensile strength increased from 9.45 MPa for the pure (PVA-PVP) film to 22.35 MPa due to the addition of 6 wt% MnO@ Fe2O3. The optical band gap decreases from 5.26 and 4.84 eV for pure (PVA/PVP) blend direct and indirect energy band gap to 5.18 and 4.71 eV for comparable values of 6wt% MnO@Fe2O3 nFs. Up to 6 wt% MnO@Fe2O3 concentration, PNC films' dielectric permittivity first declines, but it is substantially identical to the pure polymer blend matrix. The PNC sheet's dielectric permittivity increases nonlinearly with temperature, although its DC conductivity follows the Arrhenius law. Laser power was attenuated by (PVA- PVP)/MnO@Fe2O3 for both He-Ne and solid-state green laser beams. When the MnO@Fe2O3 concentration in the blend matrix rises to 6 wt%, the output power for lasers with 532 nm and 650 nm wavelengths drops from 5.49 to 2.4 mW and 19.8 to 9.4 mW, respectively. The findings suggest that nanocomposites exist and are widely recommended for optoelectronics, microelectronics, radiation detection, and several other uses.

Sustainable gelatin-kappa carrageenan active packaging with Mekwiya date seeds to enhance goat meat quality and shelf life

This research aimed to elaborate a gelatin-Kappa carrageenan-based packaging with 0.22 %, 0.44 %, and 0.88 % w/v of Mekwiya date palm seeds extract (DSEMK). This extract improved the mechanical, physical, and thermal properties of the films. Moisture content, water solubility, and water vapor permeability were reduced from 17.54 ± 0.02 to 12.18 ± 0.02, from 77.61 ± 0.02 to 25.35 ± 0.29 %, and from 5.28 ± 0.29 to 1.69 ± 0.03 g s−1 m−1 Pa−1 × 10−10, respectively. During thermal degradation, DSEMK4 film had a residual weight of 27.99 %, compared to 20.67 % for the control. Despite a decline in the film's tensile strength from 24.19 to 8.94 MPa with the incorporation of DSEMK, elongation at the breaking point increased from 37.66 ± 0.16 to 46.17 ± 0.25 %. The film containing DSEMK4 displayed the highest phenolic contents and illustrated the best antioxidant effects in DPPH and FRAP assays, with IC50s of 756 and 1445 μg/mL, respectively and inhibited pathogen growth on the meat surface. Over storage at 4 °C, monitoring of pH, lipid and protein oxidation parameters, microbial spoilage, optical properties, and sensory attributes disclosed that the DSEMK-films successfully enhanced the meat quality and safety. These findings were supported by principal component analysis and heat maps.

Symmetry change in LaNiO3 films caused by epitaxial strain from LaAlO3, SrTiO3, and DyScO3 pseudocubic (001) surfaces

To elucidate the epitaxial strain effect over a wide range of lattice mismatch, we investigated the structures of ∼25 nm thick LaNiO3 films grown on the pseudocubic (001) surfaces of three different substrates, namely, LaAlO3 (LAO), SrTiO3 (STO), and DyScO3 (DSO). Such structural information had been inferred from the intensities of a small number of Bragg reflections that relate to the NiO6 octahedral tilting in previous studies. Here, we measured more than 100 reciprocal lattice points to derive reliable structural information. The procedure of ordinary crystal structure analysis is hampered by the multidomain structure and limited volume of measurable reciprocal space, both caused by a huge, highly symmetric substrate. To overcome this difficulty, we employed the Bayesian inference to obtain the detailed atomic positions in film samples. Octahedral tilting about the c axis was dominant for the compressively strained film grown on LAO, whereas tilting about the a and b axes was dominant for the tensile strained films grown on STO and DSO. The film lattice parameters of the samples grown on STO and DSO were nearly identical, whereas additional twofold lattice modulation, including cation displacement, was only observed in the latter.

Hydrophobic bio-composites of stearic acid starch esters and micro fibrillated cellulose processed by extrusion

Fatty acid starch esters are potential candidates for obtaining hydrophobic starch-based materials. The objective was to evaluate thermoplastic bio-composites with stearic acid cassava starch esters (SAE) as matrices reinforced with micro fibrillated cellulose (MFC). SAE with 0.11 and 0.14 of DS and native cassava starch were processed with 5 % and 10 % MFC by extrusion and then thermo-compression to obtain bio-composite films. Performance of bio-composites as a function of the degree of substitution (DS) of starch esters and the content of MFC, was evaluated. Starch esterification reduced the crystalline phase and glass transition temperature of bio-composites, as confirmed by structural and thermal analysis. The increase of DS reduced the degradation temperature, which was compensated by adding MFC, favoring thermal stability. The hydrophobicity of films increased with the degree of starch esterification. Treatments with 0.14 DS formed stiffer and less tensile strength films. There was an increase in the modulus of elasticity and a reduction in elongation by increasing MFC. Fracture microscopy of films showed defects by incomplete starch melting and lack of interfacial adhesion with MFC caused by starch esterification. Starch esterification and MFC dispersion were determinants in the performance of bio-composites. In consequence, starch esterification with stearic acid reduces the compatibility with the MFC and, consequently, the performance of composites.

Optimizing film mechanical and water contact angle properties via PLA/starch/lecithin concentrations

The optimization of mechanical property and water contact angle of PLA/starch/lecithin film was conducted using response surface methodology. The tensile strength, Young's modulus and water contact angle of PLA/starch/lecithin film ranged from 0.44 ± 0.21–7.18 ± 0.57 MPa, 133.78 ± 33.7–775.57 ± 85.44 MPa and 17.71 ± 1.93–59.41 ± 28 (o), respectively. The amount of PLA and starch significantly impacts tensile strength and Young's modulus. Unlike starch, increasing PLA in the film formulation increases tensile strength and Young's modulus. The PLA-lecithin interaction decreases the film tensile strength and Young's modulus. The film water contact angle is statistically impacted by the PLA/starch interaction and quadratic term of lecithin. The adjusted R-square and p-value of each of the response ANOVA result indicates that the model quite captures the behavior of the responses. The response 2D plots also provide more insight into the variable behavior on the resulting response, making the response surface methodology a tool to design, develop and optimize PLA-based films.

Gamma irradiation-induced crosslinking and enhanced functionality of fish gelatin-agar edible films

Fish gelatin-agar edible films have potential for sustainable food packaging, but their limitations particularly water sensitivity require improvement. In this research, the effects of radiation from gamma rays at rates ranging from 0 to 40 kGy on the films' mechanical characteristics, microstructure, color, opacity, and water resistance were examined. Overall, gamma irradiation at doses of up to 30 kGy substantially improved the water resistance of the gelatin-agar film, as demonstrated by decreased water solubility, water absorption, and film vapor permeability. This could be due to crosslinking within the biopolymer network. However, at doses of 40 kGy, potential chain scission in the film's polymeric structure might occur, which counteracts further improvement and consequently starts degrading its water resistance. Similarly, the improvement of film's tensile strength and modulus of elasticity peaked at an optimal dose of 30 kGy, and then decreased at higher doses, while the film's elongation at break remained unaffected. FTIR and SEM analysis supported changes in functional group and structural morphology in these observations. Although irradiation caused some yellowing, an optimal dose range (at around 20–30 kGy) was identified to achieve improved functionality without degrading film integrity. These findings highlight the potential of gamma irradiation as a viable technique for modifying fish gelatin-agar films for enhanced performance in food packaging applications.

The Formulation and Characterization of Antimicrobial Packaging from Chitosan and Curry Leaf (Murraya Koenigii) Essential Oil for Vegetables Packaging

This study formulated chitosan-based antimicrobial films incorporating curry leaf (Murraya koenigii) essential oil using the film casting method. The films were characterized with 0%, 1%, and 2% concentrations of essential oil, and evaluated through physical, mechanical, and biological tests. Physical and mechanical tests included tensile testing, film thickness, pH, and water solubility. The film thickness ranged from 0.04 mm to 0.08 mm, and pH values ranged from 3.84 to 4.93. Water solubility was 22.7%, 20.56%, and 40.17% for films with 0%, 1%, and 2% essential oil, respectively. Tensile strength was assessed alongside antimicrobial properties using the zone of inhibition method against E. coli and Bacillus cereus. The films showed significant inhibition zones for the gram-negative E. coli and minimal inhibition for the gram-positive B. cereus. Shelf-life tests on dwarf pak choi (Brassica rapa chinensis) and baby kailan (Brassica oleracea L.) demonstrated an extended shelf-life of up to 14 days using common storage methods such as on-top placement and wrapping. This study concludes that chitosan-based films infused with curry leaf essential oil exhibit promising antimicrobial properties, making them a viable food packaging material with considerable strength, elongation, and flexibility, effectively inhibiting foodborne pathogens.

Effect of Cremophor RH40, Hydroxypropyl Methylcellulose, and Mixing Speed on Physicochemical Properties of Films Containing Nanostructured Lipid Carriers Loaded with Furosemide Using the Box-Behnken Design.

This study aimed to examine the characteristics of H-K4M hydroxypropyl methylcellulose (HPMC) films containing nanostructured lipid carriers (NLCs) loaded with furosemide. A hot homogenization technique and an ultrasonic probe were used to prepare and reduce the size of the NLCs. Films were made using the casting technique. This study used a Box-Behnken design to evaluate the influence of three key independent variables, specifically H-K4M concentration (X1), surfactant Cremophor RH40 concentration (X2), and mixing speed (X3), on the physicochemical properties of furosemide-loaded NLCs and films. The furosemide-loaded NLCs had a particle size ranging from 54.67 to 99.13 nm, and a polydispersity index (PDI) ranging from 0.246 to 0.670. All formulations exhibited a negative zeta potential, ranging from -7.05 to -5.61 mV. The prepared films had thicknesses and weights ranging from 0.1240 to 0.2034 mm and 0.0283 to 0.0450 g, respectively. The drug content was over 85%. Film surface wettability was assessed based on the contact angle, ranging from 32.27 to 68.94°. Film tensile strength varied from 1.38 to 7.77 MPa, and their elongation at break varied from 124.19 to 170.72%. The ATR-FTIR analysis confirmed the complete incorporation of the drug in the film matrix. Therefore, the appropriate selection of values for key parameters in the synthesis of HPMC films containing drug-loaded NLCs is important in the effective development of films for medical applications.

A strategy to prolong cheese shelf-life: Laminated films of bacterial cellulose and chitosan loaded with grape bagasse antioxidant extract for effective lipid oxidation delay

This study presents an innovative approach to developing bioactive composite films for food packaging applications. Laminated films composed of bacterial cellulose (BC) and chitosan were enriched with grape bagasse extract (GE) and glycerol. GE provides antioxidant capacity. Glycerol was added as plasticizer. The formulations were systematically varied to assess their mechanical and thermal properties. The assembly of the films demonstrated robust interaction between components, resulting in enhanced mechanical strength. Tensile tests revealed that GE and glycerol concentrations significantly influenced the tensile strength and elongation properties Films were obtained with Tensile Strength values that ranged between 16.92 and 32.71 MPa, but with an increase of up to 4 times in the percentage of elongation (from 2.33 to 8.63%) compared to films without GE. Puncture tests indicated that the incorporation of GE and glycerol played pivotal roles in improving puncture resistance. Predictive models were developed for better understanding. The laminated films were applied as separators for Havarti cheese, demonstrating their ability to mitigate lipid oxidation and maintaining antioxidant properties during storage. After 60 days of cheese storage, 67.3% decrease in the lipid oxidation was obtained. The findings suggest that laminated BC-chitosan films enriched with GE and glycerol could serve as effective, eco-friendly packaging materials with enhanced mechanical strength and antioxidant functionality for extending the shelf life of food products.

Thermo‐mechanical properties and optimization of sodium alginate as a polymer backbone substrate for biosensor application

AbstractThis study was aim to optimize the formulation of the sodium alginate biosensor substrate with incorporation of sodium alginate (1%‐6%(w/v)) as a polymer backbone and glycerol (10–50 wt%) as a plasticizer. The effect of their interaction on film's tensile strength (TS) and elongation at break (EB) were analyzed via response surface methodology‐central composite design (RSM‐CCD). The optimum parameter of the films for the maximum TS was at 1.90%(w/v) of sodium alginate and 17 wt% of glycerol and for maximum EB was at 4.89%(w/v) of sodium alginate and 49.65 wt% of glycerol. The optimum parameter of the films had revealed the better TS was at lower sodium alginate content and better EB was at higher glycerol content. In terms of thermal stability, the thermal decomposition temperature (Tonset) of sodium alginate decreased with the incorporation of glycerol.

Development and characterization of gelatin-based biodegradable films incorporated with pistachio shell hemicellulose

This study aimed to incorporate pistachio shell hemicellulose into a film of gelatin and glycerol for the production of biodegradable films. The gelatin and glycerol are chosen because of their functional properties, which make it extensively used in food industry. The film composition was defined after a statistical optimization by central composite face-centered design and response surface methodology. The hemicellulose/gelatin ratio of 35.93% and the glycerol ratio of 18.02% were the optimum conditions to obtain lower film water solubility, higher tensile strength, and elongation at break values. The physical, structural, mechanical, and barrier properties of the developed hemicellulose-gelatin film were analyzed and compared with those of the gelatin film. Tensile strength and film water solubility values were reduced significantly with hemicellulose incorporation from 20.41 to 16.64 MPa and 49.57 to 39.21%, respectively, while EB was enhanced by 4.34 times. In addition, hemicellulose incorporation enhanced the water vapor permeability and the film degradation in the soil. The films were also examined by Fourier transform infrared spectroscopy and differential scanning calorimetry. The novelty of this study is to use pistcahio shell hemicellulose in the production of an edible film for the first time.

Strain engineering and strain measurement by spring tethers on suspended epitaxial GaN-on-Si photonic crystal devices

Suspended epitaxial gallium nitride (GaN) on silicon (Si) photonic crystal devices suffer from large residual tensile strain, especially for long waveguides, because fine structures tend to crack due to large stress. By introducing spring-like tethers, designed by the combination of a spring network model and finite element method simulations, the stress at critical locations was mitigated and the cracking issue was solved. Meanwhile, the tethered-beam structure was found to be potentially a powerful method for high-precision strain measurement in tensile thin films, and in this case, a strain of 2.27(±0.01)×10−3 was measured in 350 nm epitaxial GaN-on-Si.

Study on the Variation of Mechanical Properties of Residual Plastic Film Over Time

The mechanical properties of residual plastic film determine the recovery rate of residual film. The mechanical properties of residual film with a thickness of 0.01mm commonly used in the semi-arid region of northeastern China were tested at different laying times. The experimental results show that the tensile strength of residual film is inversely proportional to the laying time. After crop harvesting, the longer the residual film is exposed in the field, the more significant the decrease in its mechanical properties. From the first autumn harvest to the second spring sowing, the reduction coefficient of the tensile strength of residual film is 0.35. The concept of residual film tensile strength coefficient k has been proposed, and experimental data shows that the minimum value of residual film tensile strength coefficient is 65% of the maximum value. The residual film tensile strength coefficient has a significant impact on the picking rate of residual film pickups. This study can provide reference for the design, structural improvement, and optimization of operating parameters of residual film recycling machines.

Biodegradable packaging films from banana peel fiber

Plastics are the most popular choice for packaging materials due to their strength, flexibility, and affordability. Their non-biodegradability, however, is an environmental concern and a serious human health issue that necessitates the development of sustainable and biodegradable alternatives. Towards this end, lignocellulosic residue from biowaste stands out as a viable option due to its robust structure, biocompatibility, biodegradability, low density, and non-toxicity. Herein, the lignocellulosic fiber from banana peel was extracted by alkali and bleaching treatment, solubilized in 68% ZnCl2 solution, and crosslinked through a series of Ca2+ ion concentrations, and films prepared. Results suggest that increasing Ca2+ ions concentration significantly increases the film's tensile strength but decreases moisture content, transparency, moisture absorption, water solubility, water vapor permeability, and percentage elongation. Films have a half-life of 15.26–20.72 days and biodegrade more than 50% of their weight within 3 weeks at a soil moisture of 21%. Overall, banana peel fiber could aid in designing and developing biodegradable films and offer a sustainable solution to limit the detrimental effects of plastics.

Modification of biological starch macromolecule with phosphate and dimethylammonium chloride acyloxylate substituents confers good desizability, film properties, paste stability and adhesion

This study revealed the influence of phosphorylation-dimethylammonium chloride acyloxylation (PDACA) on the desizability, film properties, paste stability, and adhesion of biological starch macromolecules. A new starch-based sizing agent, phosphorylated-dimethylammonium chloride acyloxylated starch (PDACAS), was synthesized with degrees of substitution (DS) ranging from 0.033 to 0.065. Compared to control phosphorylated-quaternized starch (PQS, 87.4 %), the desizing efficiency of cotton yarns sized with PDACAS was ~94 %, exceeding the industrial minimum requirement of 90 %. The PDACAS film tensile properties were as follows: elongation at break of 3.31 %–3.78 %, bending endurance of 1131–1537 cycles, and tensile strength of 35.83–28.31 MPa, compared with those of acid-thinned starch (ATS) film (2.74 %, 957 cycles, and 38.12 MPa). The PDACAS had paste stability of ~92 %, compared with 83.3 % for ATS. The bonding forces (an indicator of adhesion to fibers) ranged from 107.1 N to 125.3 N for cotton roving, and 128.3 N to 148.7 N for polyester/cotton roving, which were significantly better than those of ATS (95 N for cotton and 117.9 N for polyester/cotton roving). Overall, PDACA treatment effectively avoided the adverse effect of high DS quaternization on the desizability of PQS and imparted good film properties, paste stability, and adhesion to starch.

Electro-chemo-mechanical properties of anodic oxide (passive) films formed on Cu, Ni and Fe

Abstract Electro-chemo-mechanical properties of anodic oxide (passive) films formed on metals have been reviewed focusing on the results of stress variations caused by anodic oxidation of Cu, Ni, and Fe thin film electrodes in deaerated pH 8.4 borate buffer solution at 25 °C. The surface stress varies toward compressive direction due to adsorption of OH on Cu from aqueous solution as well as adsorption of oxygen on metals from gas phase. The stresses are generated with the growth of three-dimensional anodic oxide films on metals. The magnitude and sign (tensile or compressive) of the intrinsic film stress were determined by taking the residual stress of the substrate and the dielectrostriction into consideration. The tensile or compressive intrinsic film stress depends on p-type or n-type semiconductive properties of the anodic oxide films, which is explained in terms of the void formation or oxide formation in the metal side at the metal/film interface. Furthermore, the stress variation toward compressive direction during cathodic reduction of the anodic oxide films is explained in terms of the volume expansion due to the formation of intermediate species.

Evaluation of the use of Idesia polycarpa Maxim protein coating to extend the shelf life of European sweet cherries.

Idesia polycarpa Maxim protein was used as a substrate to prepare a novel food packaging material with bioactive functions for encapsulating and extending the postharvest shelf life of sweet cherries. The film-forming solution was prepared from a mixture of Idesia polycarpa Maxim protein, glycerol, and gelatin, and was cast to form a film at room temperature and evaluated for mechanical, optical, structural, crystallinity, thermal properties, morphology, and antioxidant activity. Idesia polycarpa Maxim protein composite film solution was applied as an edible coating on sweet cherries and evaluated for changes in physical and biochemical parameters of sweet cherries in storage at 20°C and 50% relative humidity for 9 days. The results showed that the film tensile strength increased from 0.589 to 1.981 Mpa and the elongation at break increased from 42.555% to 58.386% with the increase of Idesia polycarpa Maxim protein concentration. And in the in vitro antioxidant assay, IPPF-4.0% was found to have the best antioxidant activity, with scavenging rates of 65.11% ± 1.19%, 70.74% ± 0.12%, and 90.96% ± 0.49% for DPPH radicals, ABTS radicals, and hydroxyl radicals, respectively. Idesia polycarpa Maxim protein coating applied to sweet cherries and after storage at 20°C and 50% relative humidity for 9 days, it was found that the Idesia polycarpa Maxim protein coating significantly reduced the weight loss (54.82% and 34.91% in the Control and Coating-2.5% groups, respectively) and the loss of ascorbic acid content (16.47% and 37.14% in the Control and Coating-2.5% groups, respectively) of the sweet cherries, which can effectively extend the aging of sweet cherry fruits and prolong their shelf life. The developed protein film of Idesia polycarpa Maxim with antioxidant activity can be used as a new food packaging material in the food industry.

Effect of mechanical stress on the traps in silicon nitride thin films

Silicon nitride (SiNx) films were prepared by plasma enhanced chemical vapor deposition (PECVD) and different traps were induced in the films by tuning the RF power ratio during film deposition. Different initial stresses were applied to study the relationship between the mechanical stress and trap density. In-situ stress measurements showed that the film densification occurred above 400 °C during the first thermal cycling. The trap density extracted by the capacitance-voltage measurements showed its lowest value (−0.10 × 1011 cm−2eV−1) at the initial compressive stress (−730 MPa) of the film, which was explained by the hydrogen elimination due to the ion bombardment during the deposition in the compressive film. The increase in trap density (1.60 × 1011 cm−2eV−1) for the tensile films (480 MPa) is attributed to the lowering of the ion bombardment, which increases the formation of Si-H bonds. Interestingly, the performed carrier lifetime measurements for the compressive stressed SiNx films are higher (1200 μs) than the tensile stressed SiNx films (750 μs) which validate the trap density calculations. Fourier transform infrared spectra and refractive index measurements showed that the Si/N ratio increased with the increasing initial stress. Overall, we predict that our current study facilitates the formation of highly endured nitride films for different electrical and optoelectronic applications.

Extraction of microfibrillated cellulose from elephant egesta and evaluating its reinforcing ability in pectin/alginate packaging films

AbstractPectin and sodium alginate (SA) composite films were prepared by adding various concentrations of microfibrillated cellulose (MFC) via solvent casting using glycerol as a plasticizer. Herein, elephant egesta was turned into cellulose fibers from which MFC was extracted. This paper aims to examine the reinforcing property of MFC on the pectin/SA matrix. Fibrous morphology, qualitative analysis, crystallinity, and thermal stability of MFC were confirmed through SEM, FT‐IR, XRD, and TGA‐DTA analysis, respectively. The impact of various compositions of MFC (0.5%, 1%, 2%, and 5%) on the biopolymeric blend was analyzed based on mechanical and optical properties, hygroscopicity, and hydrophilicity. The outcomes revealed that adding MFC to 5% enhances the film's tensile strength by 51%. The produced film also served as a successful barrier against UV–visible light. Moreover, it exhibits a tremendous increase in contact angle and a decrease in properties such as elongation at break, moisture content (MC) and water solubility (WS). Therefore, MFC can be an excellent reinforcing agent in biodegradable polymer composites, which finds application in the food packaging industry.Highlights Microfibrillated cellulose was successfully extracted from elephant egesta and characterized. Energy efficient method of extraction. Pectin/SA films were incorporated with the extracted MFC via solvent casting. Prepared films show enhanced tensile strength and UV–visible barrier property which makes them suitable for packaging purposes. Bio‐based polymers reduce environmental pollution.

Beeswax: A review on the recent progress in the development of superhydrophobic films/coatings and their applications in fruits preservation.

Recently, the design and fabrication of bio-inspired superhydrophobic materials using natural lipid additives such as beeswax (BW) have aroused great attention in food packaging as they can minimize the transfer rate of water molecules and have effective moisture barriers. This review discusses the recent progress in the design and fabrication of BW-containing edible films/coatings (e.g., emulsion and blend films, bilayer materials, bionanocomposites, and antimicrobial materials) and their potential applications on the postharvest life and quality attributes of various fruits. Incorporation of BW into polysaccharides- and proteins-based emulsion films effectively improved their hydrophobicity, water vapor, and UV/visible light barrier properties, as well as the film tensile properties. The addition of nanoparticles to BW-based polymeric matrices often results in improved physico-mechanical properties. BW coatings have been also applied to prolong the shelf-life of various climacteric fruits, however, optimization of the wax concentration can be further investigated to develop targeted food storage systems.