Showing 7 results for Composite Film
Hossein Nourani, Seyed Mahdi Ojagh, Masoud Rezaie, Alireza Alishahi, Jaber Ghaderi,
Volume 13, Issue 1 (1-2024)
Abstract
The present study was aimed to investigate the physicomechanical properties of biodegradable ternary films based on chitosan (CH) and starch (ST) at different ratios (100ST/0CH, 75ST/25CH, 50ST/50CH, 25ST/75CH and 0ST/100CH) via a simple casting method.The results showed that adding different ratios of chitosan (25-75%) to the control film (100ST:0CH)significantly reduced the moisture content, and elongation at break (EAB) and water vapor permeability (WVP) of the films, as the 75ST:25CH ratio has the lowest values; also, the solubility, tensile strength, contact angle and whiteness index of the films showed a significant increase compared to the control (p <0.05). FT-IR spectra of different films showed interactions through hydrogen bonding between the hydroxyl moieties of ST and amino moieties of CH in the blends, which enhanced the compatibility between the two polymers. On the other hand, the indicators related to the DSC test indicated that the thermal stability of composite films reduced after the addition of ST. SEM microstructural observations clearly demonstrated a re-organization of the surface of the two-phase films due to the presence of ST.The obtained results suggested the effectiveness of blending approach in improving the compatibility of polymers and overall functionality of films.
Volume 15, Issue 80 (10-2018)
Abstract
In this study, emulsion films based on pectin were prepared by the casting method, and the effect of titanium dioxide (TiO2) nanoparticles and carnauba wax on the mechanical and the antimicrobial properties of films were studied. The results showed that water vapor permeability was decreased by increasing of nanoparticles. Mechanical tests showed that the tensile strength (TS) of films was lower than control film duo to adding wax carnauba. But TiO2 increased the TS of films. The highest TS was observed in the films incorporating 1% TiO2. Carnauba wax increased the elasticity of films, but TiO2 reduced this parameter. Results showed that both TiO2 and carnauba wax decreased the transparency of films. In the case of the yellow index, carnauba wax increased and TiO2 decreased the “b” value. Antimicrobial test results showed that the inhibitory effect of films against Escherichia coli was increased by the TiO2 and 3% TiO2 had the highest inhibitory effect. Also, the films were studied in terms of morphology and distribution of nanoparticles using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed that by increasing the nanoparticle concentration, agglomeration of nanoparticles was increased.
Volume 15, Issue 81 (11-2018)
Abstract
The increasing environmental problems caused by synthetic polymers used in food packaging demonstrate the need for extensive research into the development of biodegradable packaging. The aim of this study was to investigate the effect of adding clay nanoparticles to sodium caseinate biofilm as a factor enhancing its properties. For this purpose, composite films based on caseinat sodium with 0 to 1.5% nanoclay and 0 to 500 ppm Echinophora platyloba essential oil. The effects of nanoclay and essential oil on surface properties, transparency, mechanical properties, water vapor permeability and antioxidant properties were studied. The results showed that the addition of nanoclay has improved the mechanical properties of composites. In this regard, films made of 75 % of nanoclay have the highest tensile strength. The film containing 25% of nanoclay had the highest percentage of elongation at break point. The study of the microstructure of the film shows that the addition of nanoclay reduced the permeability of films to water vapor and also reduced the density of films and Causing their surface to become uneven. The compatibility of Echinophora Platyloba Essential Oil with caseinat sodium also produced satisfactory results in order to produce an active film of bionanocomposite. The film containing 500 ppm of essential oil showed an antioxidant activity of 78%. Overall, , The results showed that nanoclay can have positive effects on the physical properties of sodium caseinate and help to improve its properties.
Volume 18, Issue 114 (8-2021)
Abstract
Owning to drawbacks of synthetic polymers, biodegradable packaging materials (biopolymers) have received more attention both in studies and industrial applications. However, compared to conventional packaging, the biodegradable materials have some limitation must be eliminated either by using composite preparation method or introduction of nanotechnology. Inclusion of metal nanoparticles and their oxides are of the new approaches to improve the properties of packaging films. Therefore, the present study attempted to investigate the effect of ZnO (0, 2.5 and 5%) and β-glucan (0, 10 and 20%) incorporation on chemical and microbial properties of gelatin based biodegradable film over storage of chicken fillet. Results showed that incorporation the both of ZnO and β-glucan have significantly (p<0.01) improved the barrier properties against both of moisture absorption and water vapor permeability and the best properties obtained with film containing 5% of ZnO and 20% β-glucan. In addition, based on microbial tests result, it was obvious that the ZnO loaded films have antimicrobial properties and the highest inhibition activity obtained with 5% of ZnO against the all of studied pathogenic bacteria. Accordingly, the film containing 5% ZnO and 20% β-glucan is introduced as the most effective film for packaging of chicken fillets.
Volume 18, Issue 120 (12-2021)
Abstract
In this study, PET-CMC bilayer nanocomposites films containing different levels of zinc oxide nanoparticles (ZnO NPs; 0%, 1%, 2%, 3%, 4%) were prepared and characterized. For better attachment of CMC on Polyethylene terephthalate (PET), atmospheric plasma pretreatment was used. The water vapor permeability, moisture, mechanical and microbial properties of the films were analyzed. Also, in order to investigate the effect of plasma treatment on improving the properties of bilayer films, a comparison was made between plasma treated and untreated bilayer films using FTIR test. Results showed the formation of polar groups such as C=O and OH on the PET surface following the plasma treatment which improved the adhesion of the two layers of polymer to each other. The water vapor permeability of PET-CMC films containing ZnO NPs decreased compared to the pure film with increasing the ZnO NPs percentage. Increasing the nanoparticles percentage had a positive impact on the tensile strength and increased this factor from 123.77 to 466.80 MPa, while the elongation at break decreased from 48.38% to 10.59%, and the nanocomposite films were revealed more resistant compared to the pure PET-CMC film, which facilitates the transport and storing of the foodstuffs. In addition, the presence of ZnO NPs in PET-CMC films exhibited antimicrobial activity against Escherichia coli and Staphylococcus aureus. In general, this research verifies improvement in physical, mechanical, and microbial characteristics of PET-CMC nanocomposite films along with the increasing of ZnO NPs. Our findings suggest that plasma-treated PET/CMC films have the potential for application in food antimicrobial packaging and can extend the shelf-life of packaged food as active packaging.
Volume 19, Issue 132 (2-2023)
Abstract
Abstract
The perishable nature of strawberry fruit is one of the key factors that limit its consumption, specified by its decreased freshness and shelf life after harvest. The suitable packaging conditions, low temperature storage, and desired atmosphere composition inside packaged are important to preserve the quality attributes and extend the shelf life of perishable fruits. In this study, the packaging films based on PLA (such as neat PLA, PLA/TA10, and PLA/C20A1/TA10) with two different gas mixtures (such as 10 KPa O2+15 KPa CO2+75 KPa N2 (MAP-A) and 15 KPa O2+10 KPa CO2+75 KPa N2 (MAP-B)) and a control sample without gas injection on fresh strawberry fruit were evaluated. The effects of the mentioned treatments on some physicochemical properties such as weight loss, total soluble solid, tritratable acidity, pH, and firmness kept at 4 0C for 23 days of storage period were evaluated based on a completely randomized design. The results showed that the weight loss and firmness of strawberry fruit decreased during storage time, while pH value increased. The total soluble solid and tritratable acidity of all the treatments increased throughout the storage time and decreased at the end of the storage time. It has been also reported that fruits packaged in PLA/C20A1/TA10 caused better quality attributes due to lower water vapor permeability and oxygen transmission rate than two films of neat PLA and PLA/TA10. In addition, the gas mixture of MAP-A was more suitable in comparison to MAP-B due to higher carbon dioxide inside packages and lower respiration rate of strawberry fruit. Therefore, the use of nanocomposite film with modified atmosphere has been proposed to maintain strawberry fruit at a low temperature.
Volume 20, Issue 134 (4-2023)
Abstract
The aim of this research was to prepare a nanocomposite film based on Barhang (Plantago major L) seed gum. Zinc oxide (ZnO) and cellulose nanofiber (CNF) nanoparticles at the concentrations of 4 and 8% w/w were incorporated for improving the morphological, structural, thermal, water vapor permeability and mechanical properties of films. The FT-IR results confirmed the occurring of new interactions between nanoparticles and mucilage polysaccharides. XRD results indicated that the effect of ZnO on semi-crystalline structure of Barhang film is higher than the effect of CNF. The neat film has a smoth surface, but the roughness increased by addition of nanoparticles. According to TGA results, the thermal stability of films was affected by incorporation of nanoparticles, but the effect of CNF on improving the thermal stability of film was more than ZnO. The addition of nanoparticles at the concentration of 4% had no effect on the thickness of films but by increasing to 8%, the thickness increased. Moisture content and moisture absorption of films was also decreased significantly by incorporation of nanoparticles. The water vapor permeability of films was dependent on the concentration of nanoparticles and at 4%, it decreased significantly but at 8% concentration, the permeability increased again due to the aggregation of nanoparticles and their hydrophilic nature. The water contact angle of films’ surface increased by addition of ZnO but the CNF caused to decrease this value due to its hydrophilicity. The effect of CNF on improving the mechanical properties of films was better than ZnO. The CNF had the most effect on increasing tensile strength, elastic modulus and elongation to break. In general, this research indicated that by using organic and inorganic nanoreinforcements, the improving of the properties of Barhang seed gum based films is possible and the effect of CNF is more than ZnO.
