Bionanocomposite Films Research Articles

Prospective of biosynthesized L.satiVum oil/PEG/Ag-MgO bionanocomposite film for its antibacterial and anticancer potential.

A substantial interest has been manifested in utilizing oil/metal oxide hybrid bionanocomposite, especially organic/ inorganic to design different biomedical applications. The present study reports the synthesis, characterization, antibacterial and anticancer properties of biogenic silver nanoparticles (AgNPs) and L.satiVum oil/PEG/Ag-MgO bionanocomposite. The fabricated AgNPs and L.sativum oil/PEG/Ag-MgO bionanocomposite were characterized by employing different spectroscopic (UV, FTIR, XRD) and microscopic (TEM, SEM) techniques. The particle size analysis showed that the mean size of 16.32 nm for AgNPS and 13.45 nm L.satiVum oil/PEG/Ag-MgO, indicating the excellent dispersion of Ag-MgO nanoparticles in the PEG– L.satiVum oil matrix. The antimicrobial activity of AgNPs and polymeric bionanocomposite was investigated against two pathogenic bacteria. The highest antibacterial effect was observed for bionanocomposite towards Gram-positive Staphylococcus aureus (27 mm) and Gram-negative Escherichia coli (25 mm) at 40 µg/well. The bionanocomposite completely vanished the bacterial growth (100%) at 80 µgmL−1 concentrations. Moreover, the AgNPs and polymeric bionanocomposite was evaluated for anticancer activity against human cervical cancer cells (HeLa cells) at different doses (50, 250, 500, and 1000 µgmL−1). The results showed polymeric bionanocomposite was stronger in inducing the HeLa cancer cell death than AgNPs. Overall, the fabricated L.satiVum oil/PEG/Ag-MgO bionanocomposite serve as a potential antimicrobial and anticancer agent and could be used in the development of novel drugs and health care products in near future.

Preparation and characterization of bio-nanocomposite films incorporating copper nanoparticles

Antimicrobial carboxymethyl cellulose (CMC)/pectin (P)/copper (Cu) nanocomposite films were prepared by a facile approach. Copper nanoparticles (CuNPs) were prepared initially using Psidium guajava leaf extract by a green synthesis method. The CuNPs were incorporated into the CMC/P films at various concentrations. The films were characterized using a universal testing machine (mechanical strength); 2–10% CuNPs addition did not significantly increase the tensile strength, but the oxygen transmission rate (OTR) and water vapor transmission rate were changed significantly by the addition of 2% and 4% of CuNPs, respectively. The scanning electron microscopy data showed tetragonal CuNPs formation in the surface morphology of the nanocomposite films. The antimicrobial properties tests showed larger clear inhibition zones for the nanocomposite films compared to the pure CMC/P films against three different bacterial cultures. The results revealed that the CMC/P/Cu nanocomposite films could be used as an active packaging system in food applications.

Direct Comparison of Three Buckling-Based Methods to Measure the Elastic Modulus of Nanobiocomposite Thin Films.

To engineer tunable thin-film materials, the accurate measurement of their mechanical properties is crucial. However, characterizing the elastic modulus with current methods is particularly challenging for sub-micrometer thick films and hygroscopic materials because they are highly sensitive to environmental conditions and most methods require free-standing films which are difficult to prepare. In this work, we directly compared three buckling-based methods to determine the elastic moduli of supported thin films: (1) biaxial thermal shrinking, (2) uniaxial thermal shrinking, and (3) the mechanically compressed, strain-induced elastic buckling instability for mechanical measurements (SIEBIMM) method. Nanobiocomposite model films composed of cellulose nanocrystals (CNCs) and polyethyleneimine (PEI) were assembled using layer-by-layer deposition to control composition and thickness. The three buckling-based methods yielded the same trends and comparable values for the elastic moduli of each CNC-PEI film composition (ranging from 15 to 44 GPa, depending on film composition). This suggests that the methods are similarly effective for the quantification of thin-film mechanical properties. Increasing the CNC content in the films statistically increased the modulus; however, increasing the PEI content did not lead to significant changes. For the CNC-PEI system, the standard deviation of elastic moduli determined from SIEBIMM was 2-4 times larger than that for thermal shrinking, likely due to extensive cracking due to the different stress applied to the film when subjected to compression of a relaxed substrate versus the shrinking of a pre-strained substrate. These results show that biaxial thermal shrinking is a reliable method for the determination of the mechanical properties of thin films with a simple implementation and analysis and low sensitivity to small deviations in the input parameter values, such as film thickness or substrate modulus.

Orange Juice Processing Waste as a Biopolymer Base for Biodegradable Film Formation Reinforced with Cellulose Nanofiber and Activated with Nettle Essential Oil

Concerns about environmental problems have led to the development of biodegradable packaging. Food wastes as a byproduct could be a good source for biopolymers. This study aimed to describe the physical and antimicrobial features of nano biocomposite films based on orange waste powder (OWP) with different concentrations of nettle essential oil (NEO) (1.5 and 3%) as an antibacterial agent and cellulose nanofiber (CNF) (3 and 6%) as a structural reinforcement. Thus, Field emission scanning electron microscopy (FE-SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and differential scanning calorimetry analysis (DSC) were performed. Further, tensile strength, elongation at break, water vapor permeability, and antimicrobial properties were investigated. As a result, the addition of CNF improved the tensile strength and water barrier properties of the samples. Compared to the control film, adding NEO (3%) decreased the tensile strength but increased water vapor permeability and melting temperature. Moreover, the OWP-based film samples had an antimicrobial effect against five foodborne pathogens; this effect was increased considerably by enhancing the NEO concentration. In this regard, the maximum and minimum susceptibility was related to the Staphylococcus aureus and Salmonella enterica, respectively. In conclusion, orange waste could be used to produce an active film with improved physicomechanical and antibacterial properties by incorporating CNF and NEO.

The synergistic effects of zinc oxide nanoparticles and fennel essential oil on physicochemical, mechanical, and antibacterial properties of potato starch films.

The purpose of this study was to evaluate the effects of a combination of zinc oxide (ZnO‐N) nanoparticles and fennel essential oil (FEO) on the functional and antimicrobial properties of potato starch films. Films based on potato starch containing a combination of ZnO‐N (1, 3, and 5%(w/w)) and FEO (1, 2, and 3% (w/w)) produced by casting method and water solubility, water absorption capacity (WAC), barrier properties, mechanical properties, color indexes, and antimicrobial activity of the films against Staphylococcus aureus, Escherichia coli, and Aspergillus flavus were studied. The combination of ZnO‐N and FEO had a significant decreasing effect on solubility, WAC, water vapor and oxygen permeability, elongation, and L* index. These additives had an increasing impact on tensile strength, Yang's modulus, and a* and b* indexes (p < .05). By increasing the concentration of ZnO‐N and FEO, the antimicrobial activities of bionanocomposite films significantly increased (p < .05). Both ZnO‐N and FEO had a significant effect in this respect, although the effects of ZnO‐N were more significant. In conclusion, an excellent synergistic effect of ZnO‐N and FEO was observed in potato starch films.

Visible light responsive, self-activated bionanocomposite films with sustained antimicrobial activity for food packaging

The research on a new type of low-cost, less-loss and adjustable sustained antibacterial activity food packaging films with self-activation ability and great industrialization potentiality is of great scientific and technological interest. Herein, a novel chitosan/negatively charged graphitic carbon nitride self-activation bionanocomposite films was prepared by one-step electrostatic self-assembly. First, the antibacterial efficiency of this film could reach to 99.8 ± 0.26% against E. coli and 99.9 ± 0.04% against S. aureus through self-activated under visible light. Second, this film can effectively extend the shelf life of tangerines to 24 days. Hemolysis and cell experiment test proved that this film was safe and nontoxic. Finally, negatively charged graphitic carbon nitride with low-cost can improve the mechanical, thermal and hydrophobic properties of neat chitosan films. This work can provide a new pathway for the preparation of low-cost packaging films with excellent visible light responsive property and sustainable antibacterial activity.

Effects of nanocellulose fiber and thymol on mechanical, thermal, and barrier properties of corn starch films

This study explores the preparation of corn starch (CS) films incorporated with nanocellulose fiber (NCF) and different concentrations of thymol (0.1, 0.3, and 0.5% weight of thymol/volume of solution (% w/v)) via the solvent casting method. The resulting films were characterized by the functional chemistry, crystallinity, morphology, mechanical, thermal, and barrier properties. The Fourier transform infrared spectroscopy analysis confirmed the presence of intermolecular hydrogen bonding between the thymol and starch, as well as the thymol and glycerol, via hydroxyl groups of glycerol, starch, and thymol. The film crystallinity decreased with increasing concentration of thymol. The addition of NCF at 1.5% weight of starch increased the tensile strength (TS) and Young's Modulus (YM), but decreased the elongation at break (EAB), oxygen permeability, and water vapor permeability of the CS films. The thermal stability of the CS films was also improved with the addition of NCF. The addition of thymol to the CS/NCF bio-nanocomposite films decreased the TS and YM, respectively but increased the EAB due to the plasticizing effect of thymol. The addition of thymol also improved the thermal stability but reduced the barrier properties of the films. The effects on the mechanical, thermal, and barrier properties were more pronounced at higher concentrations of thymol. In conclusion, the inclusion of both NCF and thymol led to the improvement of the flexibility and thermal stability of the CS films.

Development of cost-effective transparent bionanocomposite films based on pullulan and cellulose nanofibers for packaging application

In recent years, the preparation of bio-based edible films for packaging material is increasing due to its easy availability, low cost, renewability and biodegradability. The present work aims to develop pullulan and cellulose nanofibers based novel bionanocomposite films with improved barrier and mechanical properties by solution casting method. The prepared films were characterized for morphology, crystalline structure, chemical interaction, optical properties, hydrophilicity, barrier properties, thermal stability and mechanical properties. Incorporation of cellulose nanofibers increases the tensile strength of the bionanocomposite film up to 60% than the pristine pullulan film. Barrier properties (water vapor transmission rate and oxygen transmission rate of bionanocomposite films were 32 and 38%, respectively lower when compared to the pristine pullulan film). Additionally, these bionanocomposite films were homogeneous, transparent, and had good thermal stability. Moreover, these bionanocomposite films were prepared entirely from natural resources and could be used as an eco-friendly edible film for packaging.

Investigation of Nano-Biocomposite for Kashar Cheese and Ground Meat Packaging

Background: Plastic and polymeric materials remain in the soil given the fact that they are derived from petroleum resources. However, such pollution has created a special challenge for human societies. The use of biodegradable packaging has received more attention. The general purpose of this study was to investigate the use of a mixture film of whey protein concentrate and reinforced hydroxypropyl methylcellulose with chitosan nanoparticles to package ground meat and Kashar cheese. Furthermore, this package was compared with ordinary polyethylene coating. Methods: Two samples of ground meat and Kashar cheese were packaged using a nano-biocomposite film of whey protein concentrate/ hydroxypropyl methylcellulose (70:30) containing 3% chitosan nanoparticles. The antimicrobial properties of the optimal produced film were examined. The total population of microorganisms and pH for ground meat were tested during 6 days of storage. The total population of microorganisms, weight loss, moisture content, pH, and mold count and yeast for Kashar cheese were examined during 2 months of storage. The results of the tests were analyzed by Duncan one-way analysis of variance with 95% confidence and 5% error by Minitab16 software. Results: Samples of ground meat and cheese packaged in whey protein film and hydroxypropyl methylcellulose containing chitosan nanoparticles had less mold count, yeast, and total microorganism population than polyethylene packaging (P ≤ 0.05) after storage period. Conclusion: The use of biodegradable films based on plants and the loading of nanoparticles can lead to the use of this type of packaging for perishable food to prevent environmental hazards in addition to greater safety of perishable food products.

Effect of orange waste based nanobiocomposite film containing nettle essential oil and cellulose nanofiber on microbial and chemical characteristics of beef

Beef is considered the main source of dietary protein despite being perishable. In this regard, utilization of biodegradable films containing plant essential oils, as antimicrobial compounds, is one of the concepts to prolong the beef shelf life. Accordingly, this study aimed to investigate the effect of the biodegradable film based on orange waste powder (OWP) containing nettle essential oil (NEO) and cellulose nanofiber (CNF) to increase the shelf life of the refrigerated beef samples stored for 12 days. As well, beef samples were divided into three groups of uncovered (control), wrapped with the OWP-based film without essential oil and nanofiber and wrapped with OWP-base film containing 3% NEO and 6% CNF and the microbial (aerobic mesophilic count, psychrophilic count, and coliform count) and chemical (pH, thiobarbituric acid and volatile nitrogen bases) properties were evaluated at regular intervals (0, 4, 8 and 12days). According to the results, the beef sample wrapped with OWP-base film containing 3% NEO and 6% CNF showed the lowest growth rate of the mentioned bacteria after 12 days of storage; Moreover, the samples covered by the film containing NEO and CNF had lower levels of pH, thiobarbituric acid and volatile nitrogen bases values compared to the other two samples at 12th day of storage. The results of this study indicate that wrapping beef samples with an OWP-based nanobiocomposite film containing 3% NEO and 6% CNF could remarkably prolong its shelf life in refrigerated conditions. TRANSLATE with x English Arabic Hebrew Polish Bulgarian Hindi Portuguese Catalan Hmong Daw Romanian Chinese Simplified Hungarian Russian Chinese Traditional Indonesian Slovak Czech Italian Slovenian Danish Japanese Spanish Dutch Klingon Swedish English Korean Thai Estonian Latvian Turkish Finnish Lithuanian Ukrainian French Malay Urdu German Maltese Vietnamese Greek Norwegian Welsh Haitian Creole Persian // TRANSLATE with COPY THE URL BELOW Back EMBED THE SNIPPET BELOW IN YOUR SITE Enable collaborative features and customize widget: Bing Webmaster Portal Back // TRANSLATE with x English Arabic Hebrew Polish Bulgarian Hindi Portuguese Catalan Hmong Daw Romanian Chinese Simplified Hungarian Russian Chinese Traditional Indonesian Slovak Czech Italian Slovenian Danish Japanese Spanish Dutch Klingon Swedish English Korean Thai Estonian Latvian Turkish Finnish Lithuanian Ukrainian French Malay Urdu German Maltese Vietnamese Greek Norwegian Welsh Haitian Creole Persian // TRANSLATE with COPY THE URL BELOW Back EMBED THE SNIPPET BELOW IN YOUR SITE Enable collaborative features and customize widget: Bing Webmaster Portal Back //TRANSLATE with xEnglishArabicHebrewPolishBulgarianHindiPortugueseCatalanHmong DawRomanianChinese SimplifiedHungarianRussianChinese TraditionalIndonesianSlovakCzechItalianSlovenianDanishJapaneseSpanishDutchKlingonSwedishEnglishKoreanThaiEstonianLatvianTurkishFinnishLithuanianUkrainianFrenchMalayUrduGermanMalteseVietnameseGreekNorwegianWelshHaitian CreolePersian // TRANSLATE with COPY THE URL BELOW BackEMBED THE SNIPPET BELOW IN YOUR SITE Enable collaborative features and customize widget: Bing Webmaster PortalBack//

Chitosan Ternary Bio Nanocomposite Films Incorporated with MMT K10 Nanoclay and Spirulina

It is enviable to develop an environment-friendly packaging material against petroleum-based polymers with enhanced functionality to satisfy sustainable development and to secure and extend the shelf life of food. In this work, biopolymer chitosan was mixed with montmorillonite (MMT K10) nanoclay and spirulina algae to produce a bio nanocomposite film with high strength and barrier properties. Spirulina and MMT K10 was initially incorporated into chitosan to fabricate the chitosan/MMT K10/spirulina bio nanocomposite and the intermolecular interactions between the chitosan, MMT K10 and spirulina was improved by the synergistic effect of covalent and hydrogen bonds. The surface colour and opacity of chitosan bio nanocomposite films were found to be increased by the inclusion of MMT K10 and spirulina. The bio nanocomposite films exhibited good solubility and swelling property. The chitosan bio nanocomposite film with 0.5 g of spirulina revealed the promising features such as high tensile strength of 46.3 MPa, low oxygen and watervapour transmission rate of 996.79 cc/(m2. day.atm) and 7.12 g/m2/day which was better than other various concentration of spirulina based films. Furthermore, the antimicrobial properties of bio nanocomposite films were determined by colony count method and the results suggested the films had excellent antimicrobial properties against both gram-positive and gram-negative microorganisms and the composite films showed the good biodegradable property. The fabricated chitosan-based MMT K10 and spirulina incorporated bio nanocomposite films could make valuable contributions in active food packaging applications due to its excellent properties.

Biodegradable nano composite film based on modified starch-albumin/MgO; antibacterial, antioxidant and structural properties

In this study, an antibacterial/antioxidant film based on modified starch and albumin was prepared in which magnesium oxide nanoparticles (MgO) at concentrations of 0–5 w/w% were used to improve the physicochemical properties of biopolymers. For this purpose, various modified starch/albumin films containing magnesium oxide nanoparticles (S-A-MgO) were synthesized based on the D-Optimal experimental design. Thickness, moisture content, water solubility, water vapor permeability (WVP) and antioxidant properties were analyzed for 19 films prepared according to the statistical design. Then, the antimicrobial properties and structure of films was evaluated using FTIR, SEM, XRD, and TGA techniques. The results of the tests showed that with the addition of magnesium oxide nanoparticles, the thickness of the produced films increased, moisture content, water solubility and water vapor permeability decreased. The use of magnesium oxide nanoparticles in nanobiocomposite films increased antioxidant activity. Morphological images (SEM) of the produced films showed a rough and heterogeneous surface in films containing magnesium oxide nanoparticles compared to films without nanoparticles. The results of FT-IR indicated that there was no new bond between the starch-albumin functional groups and MgO and the physical presence of MgO nanoparticles in the polymer matrix was confirmed. XRD results showed that in films containing MgO nanoparticles, a wide peak of about 2θ = 16.5° formed, indicating their relative amorphous structure. In investigating the antibacterial effect of films containing nanoparticles, halos with a diameter of about 4–6 mm against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was formed, which showed the antimicrobial properties of the prepared films.

Antimicrobial bio-nanocomposite films based on gelatin, tragacanth, and zinc oxide nanoparticles – Microstructural, mechanical, thermo-physical, and barrier properties

Gelatin and tragacanth were employed to fabricate antimicrobial nanocomposites with 1, 3, and 5% zinc oxide nanoparticles (ZnO-NPs). FT-IR and XRD proved new chemical interactions among GEL/TGC/ZnO-NPs and higher crystallinity of nanocomposites, respectively. DSC showed a significant increase in melting point temperature (Tm) from ~ 90 to ~ 93–101 °C after adding 1–5% ZnO-NPs. Ultimate tensile strength (UTS) was remarkably increased to 31.21, 34.57, and 35.06 MPa, as well as Young’s Modulus to 287.44, 335.47, and 367.04 MPa after incorporating 1, 3, and 5% ZnO-NPs. The ZnO-NPs dose-dependently reduced the water vapor permeability (WVP) of the films. FE-SEM analysis from surface and cross-section illustrated the compact and homogenous structure of the nanocomposites even up to 5% ZnO-NPs. The ZnO-NPs-containing nanocomposites had a good antimicrobial activity (~10–20 mm) against both Staphylococcus aureus and Escherichia coli. Generally, the results indicated that the prepared nanocomposite films are promising antimicrobial bio-materials for food packaging.

Development of novel collagen hydrolysate bio-nanocomposite films extracted from hide trimming wastes reinforced with chitosan nanoparticles

The wide availability of pollutant by-products from the leather industries has been a key factor in driving the research into converting these low-cost by-products into high value-added collagen-based products. In this study, collagen hydrolysate (CH) was extracted from hide trimming waste from the tanneries and used to prepare biodegradable films with chitosan nanoparticles (CNPs) with different concentrations to develop an alternative product to non-biodegradable plastics. The effects of CNPs concentration on the thickness, mechanical, water barrier, thermal, light transmittance, color properties, and opacity of CH-based films were investigated. The results clearly show that the tensile strength and elastic modulus values of CH/CNPs films increase significantly as the concentration of CNPs increases, while the elongation at break, water solubility, and water vapor permeability values decrease. In addition, scanning electron microscopy (SEM) showed uniform distributions of CNPs in the CH-based films. Based on the results obtained, the extraction of CH from hide trimming wastes and reuse in the production of biodegradable films will both prevent these valuable wastes from being dispose into the landfills and will be an alternative to fossil-derived plastics in the future.

Electrically Conducting Pullulan-Based Nanobiocomposites Using Carbon Nanotubes and TEMPO Cellulose Nanofibril.

Hybrid nanobiocomposite films are prepared using a solution casting by incorporating TEMPO cellulose nanofibrils (TOCNs) and carbon nanotubes (CNTs) into an aqueous solution of pullulan (PULL). The presence of CNT is confirmed by XRD characterization, and the prepared film shows an increased degree of crystallinity after the addition of TOCNs and CNT. The maximum degree of crystallinity value is obtained for CNT 0.5 % (59.64%). According to the Fourier-transform infrared spectroscopy, the shifts of the characteristic -OH peak of PULL occurred after the addition of TOCNs and aqueous CNT (3306.39 to 3246.90 cm−1), confirming interaction between the TOCNs, CNTs, and PULL matrix. The prepared films show enhanced material properties including higher tensile strength (65.41 MPa at low CNT content (0.5%)), water barrier properties, and reduced moisture susceptibility (5 wt.% CNT shows the lowest value (11.28%)) compared with the neat PULL film. Additionally, the prepared films are almost biodegradable within 64 days and show excellent electrical conductivity (0.001 to 0.015 S/mm for 0.5–5% CNT), which suggests a new approach to transform natural polymers into novel advanced materials for use in the fields of biosensing and electronics.

Green synthesis of chitosan/nanosilver hybrid bionanocomposites with promising antimicrobial, antioxidant and anticervical cancer activity

Being a versatile biopolymer, chitosan has been used to synthesize silver nanoparticles (SNPs) impregnated hybrid chitosan-nanosilver bionanocomposite (CSSNC) films via a green ex-situ and in-situ route using fruit waste extract. CSSNC hybrid bionanocomposite films were prepared in six different concentrations and characterized by using different techniques i.e. UV-visible spectroscopy, FT-IR spectroscopy, Thermogravimetric analysis, X-Ray Diffraction and Scanning Electron Microscopy. Among the CSSNC, CS9AGE1 has been optimized for further biological assays for which the antimicrobial activity revealed the highest zone of inhibition against E. coli (20 mm) and S. aureus (17.5 mm). The antioxidant activity revealed dose-dependent radical scavenging against 2,2-diphenyl-1-picrylhydrazyl (DPPH) (50 µg mL−1), nitric oxide (50 µg mL−1) radical, and total reduction capability (40 µg mL−1). Furthermore, low percent cell viability was observed for cancerous cells at a concentration of 50 µg mL−1 against cervical cancer cells, (HeLa cell line). Therefore, the overall accomplishment confesses a strong potential of CSSNC fabrication via an eco-friendly route exhibiting remarkable anticancer and antioxidant activity and hence provide a gateway to be further explored in the biomedical sciences.

Development of gum arabic-based nanocomposite films reinforced with cellulose nanocrystals for strawberry preservation

The present study aimed to develop a new bio-nanocomposite film based on gum arabic (GA) reinforced with cellulose nanocrystals (CNC). CNC was successfully fabricated and its microstructure was characterized. Subsequently, the effects of CNC on the rheological, physicochemical and functional properties of GA-based films were systematically evaluated. Results showed that the tensile strength (2.21 MPa) and elongation at break (62.79%) of film incorporated with 4% (w/w) CNC were effectively increased compared with the GA film (1.08 MPa and 42.50%). Additionally, 4% CNC reduced the water vapor and oxygen permeability by 10.61% and 25.30% respectively, while improved the ultraviolet light barrier and thermal stability of film. The well dispersion and filling effect of nanofiller contributed to form a compact and homogeneous film structure. Furthermore, the film containing 4% CNC decreased the weight loss of strawberries by 23.80% compared with the control group, thus delaying the deterioration of strawberry quality during storage.

ZnO NPs Doped PVA/Spathodea campanulata Thin Films for Food Packaging

The present study aims to investigate the influence of Zinc Oxide nanoparticles (ZnO NPs) on the physicochemical properties of poly(vinyl alcohol)/Spathodea campanulata bud fluid (PSC) matrix. The FITR study assured the physical interaction between ZnO NPs and the PSC matrix. Tensile strength was enhanced by 18% with the incorporation of ZnO NPs into the PSC matrix. The DSC measurements depicted an increased glass transition temperature than PSC matrix at lower content of ZnO NPs. The thermal stability of nanocomposite films was remarkably improved (about 50 °C). The XRD results depicted the homogeneous distribution of ZnO NPs in the PSC matrix. The morphology studies revealed the homogeneity due to good dispersion of ZnO NPs. The water contact angle findings shown the nanocomposite films were hydrophilic. The nanocomposites have shown only 2.8% solubility in water. The WVTR of nanocomposite films was improved by 56%. The bionanocomposite films exhibited good antibacterial activity and excellent preservation capacity and could be a potent alternative to the nonbiodegradable packaging material.

Chitosan-based films reinforced with cellulose nanofibrils isolated from Euterpe oleraceae MART

The use of local raw materials for the production of biodegradable films can simultaneously contribute to the development of the Amazon and global sustainability. This work aimed to evaluate the physical and mechanical performance of chitosan-based bionanocomposite films reinforced with different loads of cellulose nanofibrils obtained from açaí ( Euterpe oleraceae Mart.) under two nanofibrillation degrees. Nanofibrils were obtained by 3 and 21 passages in a grinder defibrillator. The films were produced by casting with nanofibril reinforcement at 5 wt.%, 10 wt.%, 15 wt.%, and 20 wt.%. The increase in the nanofibril level and nanofibrillation degree reduced water vapor absorption (75.20% to 51.93%), water solubility (28.33% to 17.91%), and density (0.87 g.cm−3 to 0.61 g.cm−3). The water vapor permeability decreased with higher nanofibril loads for both 3-pass (47.30% to 43.61%) and 21-pass (49.82% to 44.48%) reinforced films, but not with nanofibrillation degree. The increase in 3-pass nanofibril level decreased tensile strength (8.18 MPa to 7.88 MPa), modulus of elasticity (867.62 MPa to 670.02 MPa) and elongation at break (0.02 mm.mm−1 to 0.01 mm.mm−1). However, the opposite effect happened to 21-pass nanofibrils, with increases from 9.16 MPa to 9.73 MPa and from 502.00 MPa to 1119.62 MPa for tensile strength and modulus of elasticity, respectively. Meanwhile, the maximum elongation at rupture did not vary. It was concluded that chitosan-based bionanocomposite films reinforced with 20 wt.% of 21-pass nanofibril were more resistant, except for water vapor permeability. Adding coarser nanofibrils enhanced this property. The 3-pass nanofibrils reinforcement enables water solubility, which benefits other packaging applications.

Investigation of Functionalized Surface Charges of Thermoplastic Starch/Zinc Oxide Nanocomposite Films Using Polyaniline: The Potential of Improved Antibacterial Properties.

Improving the antibacterial activity of biodegradable materials is crucial for combatting widespread drug-resistant bacteria and plastic pollutants. In this work, we studied polyaniline (PANI)-functionalized zinc oxide nanoparticles (ZnO NPs) to improve surface charges. A PANI-functionalized ZnO NP surface was prepared using a simple impregnation technique. The PANI functionalization of ZnO successfully increased the positive surface charge of the ZnO NPs. In addition, PANI-functionalized ZnO improved mechanical properties and thermal stability. Besides those properties, the water permeability of the bionanocomposite films was decreased due to their increased hydrophobicity. PANI-functionalized ZnO NPs were applied to thermoplastic starch (TPS) films for physical properties and antibacterial studies using Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The PANI-functionalized ZnO bionanocomposite films exhibited excellent antibacterial activity for both E. coli (76%) and S. aureus (72%). This result suggests that PANI-functionalized ZnO NPs can improve the antibacterial activity of TPS-based bionanocomposite films.