Incorporation Of Zinc Oxide Nanoparticles Research Articles

Optimized UV-barrier carboxymethyl cellulose-based edible coatings reinforced with green synthesized ZnO-NPs for food packaging applications

AbstractThe widespread use of sodium carboxymethyl cellulose (CMC) in the production of edible coatings is returned to its biodegradable, biocompatible, and non-toxic nature. However, neat CMC edible coatings lack UV-shielding activity and have poor antimicrobial properties. This study aimed to develop a CMC-based coating with optimal UV-barrier properties by incorporating aloe vera (AV) and green synthesized zinc oxide nanoparticles (ZnO-NPs). The composition and synergistic effects of CMC, AV, and ZnO-NPs were optimized using central composite design to achieve the best UV-barrier properties. When using the optimized compositions of CMC (1.0 g), AV (3.0 g), and ZnO-NPs (5.0 wt%), the minimum UV-transmittance achieved was 4.75%. Fourier transform infra-red and wide-angle X-ray diffraction were used to confirm the interactions between the coating components. The incorporation of ZnO-NPs into CMC/AV was validated through surface morphology analysis via scanning electron microscopy and by examining the distribution of ZnO-NPs using transmission electron microscopy. CMC/AV/ZnO-NPs coatings showed excellent water barrier, mechanical, thermal, and antimicrobial properties when compared with the neat carboxymethyl cellulose coating. In addition, CMC/AV/ZnO-NPs coatings significantly resisted both mass loss and spoilage of green capsicum for a 15-day storage period. These results proved that the optimized coating could replace the plastic packaging candidates and be used potentially to preserve food products.

Starch-chitosan-Taro mucilage nanocomposite active food packaging film doped with zinc oxide nanoparticles – Fabrication, mechanical properties, anti-bacterial activity and eco toxicity assessment

In this research, a novel active food packaging material was developed by blending starch, chitosan, and plant-based mucilage with zinc oxide nanoparticles. The polymeric nanocomposite film, created by incorporating zinc oxide nanoparticles into the mixture using a straightforward approach, was analyzed for its structural and functional attributes using FTIR, XRD, SEM, and TGA/DSC. These analyses revealed a robust interaction between the polymers' functional groups and the nanoparticles, forming a stable film. The film's mechanical properties, including tensile strength and Young's modulus, were high. It also showed reduced wettability and water solubility, enhancing water resistance. The biodegradability rate was 100 %. Antibacterial tests against Bacillus sp. and Pseudomonas sp. showed significant inhibition zones of 26 mm and 30 mm, respectively, demonstrating strong antibacterial effectiveness. The film's non-target toxicity was assessed through phytotoxicity experiments on Vigna angularis and soil nutrient evaluations, with no negative impact on plant growth or soil health observed. These results indicate that this nanocomposite is a safe, biocompatible option for food packaging.

Fabrication of Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)/ZnO Nanocomposite Films for Active Packaging Applications: Impact of ZnO Type on Structure-Property Dynamics.

Bio-based and biodegradable polyhydroxyalkanoates (PHAs) have great potential as sustainable packaging materials. The incorporation of zinc oxide nanoparticles (ZnO NPs) could further improve their functional properties by providing enhanced barrier and antimicrobial properties, although current literature lacks details on how the characteristics of ZnO influence the structure-property relationships in PHA/ZnO nanocomposites. Therefore, commercial ZnO NPs with different morphologies (rod-like, spherical) and silane surface modification are incorporated into poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) via extrusion and compression molding. All ZnO NPs are homogeneously distributed in the PHBHHx matrix at 1, 3 and 5 wt.%, but finer dispersion is achieved with modified ZnO. No chemical interactions between ZnO and PHBHHx are observed due to a lack of hydroxyl groups on ZnO. The fabricated nanocomposite films retain the flexible properties of PHBHHx with minimal impact of ZnO NPs on crystallization kinetics and the degree of crystallinity (53 to 56%). The opacity gradually increases with ZnO loading, while remaining translucent up to 5 wt.% ZnO and providing an effective UV barrier. Improved oxygen barrier and antibacterial effects against S. aureus are dependent on the intrinsic characteristics of ZnO rather than its morphology. We conclude that PHBHHx retains its favorable processing properties while producing nanocomposite films that are suitable as flexible active packaging materials.

Synthesis and Evaluation of Gelatin-Chitosan Biofilms Incorporating Zinc Oxide Nanoparticles and 5-Fluorouracil for Cancer Treatment.

In this study, a novel multifunctional biofilm was fabricated using a straightforward casting process. The biofilm comprised gelatin, chitosan, 5-fluorouracil (5-FU)-conjugated zinc oxide nanoparticles, and polyvinyl alcohol plasticized with glycerol. The 5-FU-conjugated nanoparticles were synthesized via a single-step co-precipitation process, offering a unique approach. Characterization confirmed successful drug conjugation, revealing bar-shaped nanoparticles with sizes ranging from 90 to 100 nm. Drug release kinetics followed the Korsmeyer-Peppas model, indicating controlled release behavior. Maximum swelling ratio studies of the gelatin-chitosan film showed pH-dependent characteristics, highlighting its versatility. Comprehensive analysis using SEM, FT-IR, Raman, and EDX spectra confirmed the presence of gelatin, chitosan, and 5-FU/ZnO nanoparticles within the biofilms. These biofilms exhibited non-cytotoxicity to human fibroblasts and significant anticancer activity against skin cancer cells, demonstrating their potential for biomedical applications. This versatility positions the 5-FU/ZnO-loaded sheets as promising candidates for localized topical patches in skin and oral cancer treatment, underscoring their practicality and adaptability for therapeutic applications.

Spherical polystyrene/zinc oxide nanocomposite powder fabricated by continuous process chain of melt mixing and indirect heating

Polymer powders are limited by particle size, shape, and properties in various applications. Preserving the chemical properties of the material throughout the process is a critical part of developing consistently shaped nanocomposite powders across diverse polymer types. The goal of this study is to demonstrate continuous methods to produce spherical Polystyrene (PS) and zinc oxide (ZnO) nanocomposites. A single-screw extruder is used to melt mix PS pellets with ZnO nanoparticles, followed by pelletization, dry grinding, and spheroidization in a Downer Tower to form spherical polymers. To minimize agglomeration, the process incorporates an ethanol treatment and a final sieving step. The resulting nanocomposite powder exhibits exceptional flowability and well-defined spherical morphology. Additionally, incorporating ZnO nanoparticles enhanced the thermal stability and glass transition temperature of the nanocomposite while reducing particle size distribution. Thermogravimetric analysis and X-ray diffraction confirm the preservation of the chemical structure of the spherical nanocomposite specimens throughout processing.

Polyurethane nanofiber scaffolds for future bone tissue applications: Using β‐cyclodextrin and zinc oxide nanoparticles to improve the properties

AbstractNumerous strategies exist to design a suitable bone graft made from polyurethane (PU) nanofibers. However, using PU nanofibers is impractical owing to their hydrophobicity. This work transforms the hydrophobicity of PU nanofibers using β‐cyclodextrin (β‐CD) and zinc oxide (ZnO) nanoparticles (NPs). Transmission and scanning electron microscopy (SEM) indicated the size of ~100 to 200 nm for ZnO NPs, and these NPs could finely harmonize inside nanofibers. The phenolphthalein absorbance test confirmed the inclusion of ZnO and β‐CD. Fourier transform infrared, X‐ray diffraction, and photoelectron spectroscopy showed that synthesized composites have intermolecular hydrogen interactions between the PU, β‐CD, and ZnO NPs. These embellishments improved the hydrophilicity from a contact angle of 60.2 ± 0.2° to 0°. The tensile strength of modified fibers increased from 2.16 ± 0.14 to 6.65 ± 6.0 MPa. The incorporation of ZnO NPs caused the mineralization of the nanofibers and the maximum number of hydroxyapatite NPs in the composite, which had the highest concentration of ZnO NPs. These nanofiber mats boosted the proliferation of Human Embryonic Kidney 293 T cells till 6 days of culture for the nanofiber with 5% β‐CD and 75 mg ZnO NPs combination. Cell fixation studies indicated the successful attachment of cells onto nanofibers. Consequently, our multifunctional scaffolds could be osteoproductive and osteoinductive biomaterials for future bone tissue engineering.

Construction of interfacial interlocking structure in epoxy composites with enhanced mechanical performance and ultraviolet resistance

Replacing carbon fibers with organic fibers to reinforce the polymer matrix has become a promising development direction in the preparation of structural composites owing to its low density and cost, but the mechanical performance of organic fibers restricts their further application. Herein, poly(vinyl alcohol) (PVA) fibers were utilized to reinforce the epoxy resin (EP) through the incorporation of zinc oxide nanoparticles (ZnO NPs) in PVA solution (PVAS), and high-strength composite for 122.3 MPa with interfacial interlocking structure was successfully fabricated via vacuum assisted resin transfer molding (VARTM). ZnO NPs were coated on the PVA fibers and enhanced the surface roughness, which improved the mechanical performance of the composite. In comparison with untreated composites, the interlaminar shear strength (ILSS) of composites displayed a significant increase, from 99.4 MPa to 122.3 MPa, resulting from improved interfacial bonding and reduced interfacial gap. Simultaneously, the incorporation of ZnO NPs efficiently enhanced the ultraviolet (UV) resistance.

Development of carboxymethyl cellulose-based nanocomposite incorporated with ZnO nanoparticles synthesized by cress seed mucilage as green surfactant

This study aimed to enhance carboxymethyl cellulose (CMC)-based films by incorporating zinc oxide nanoparticles (ZnO NPs) and cress seed mucilage (CSM), with a view to augmenting the physical, mechanical, and permeability properties of the resulting nanocomposite films. For the first time, CSM was exploited as a green surfactant to synthetize ZnO NPs using hydrothermal method. Seven distinct film samples were meticulously produced and subjected to a comprehensive array of analyses. The findings revealed that the incorporation of CSM/ZnO-5 % improved the physical properties of the films, demonstrating a significant reduction in moisture content and water vapor permeability (WVP). Increasing the concentration of NPs in conjunction with CSM markedly decreased the solubility of the nanocomposites by up to 56 %. The films containing CSM/ZnO showed higher tensile strength and elongation at the break values. The UV absorption of the films exhibited a substantial rise with the addition of ZnO NPs, particularly with an increased content in the presence of CSM. The thermal stability of nanocomposites containing a high concentration of CSM/ZnO exhibited an improvement compared to the control sample. In light of these results, the CMC/CSM/ZnO-5 % film emerges as a promising candidate for a biocompatible packaging material, exhibiting favorable physical characteristics.

"Nano in Nano"-Incorporation of ZnO Nanoparticles into Cellulose Acetate-Poly(Ethylene Oxide) Composite Nanofibers Using Solution Blow Spinning.

In this work, the preparation and characterization of composites from cellulose acetate (CA)-poly(ethylene oxide) (PEO) nanofibers (NFs) with incorporated zinc oxide nanoparticles (ZnO-NPs) using solution blow spinning (SBS) is reported. CA-PEO nanofibers were produced by spinning solution that contained a higher CA-to-PEO ratio and lower (equal) CA-to-PEO ratio. Nanoparticles were added to comprise 2.5% and 5% of the solution, calculated on the weight of the polymers. To have better control of the SBS processing conditions, characterization of the spinning suspensions is carried out, which reveals a decrease in viscosity (two- to eightfold) upon the addition of NPs. It is observed that this variation of viscosity does not significantly affect the mean diameters of nanofibers, but does affect the mode of the nanofibers' size distribution, whereby lower viscosity provides thinner fibers. FESEM-EDS confirms ZnO NP encapsulation into nanofibers, specifically into the CA component based on UV-vis studies, since the release of ZnO is not detected for up to 5 days in deionized water, despite the significant swelling of the material and accompanied dissolution of water-soluble PEO. Upon the dissolution of CA nanofibers into acetone, immediate release of ZnO is detected, both visually and by spectrometer. ATR-FTIR studies reveal interaction of ZnO with the CA component of composite nanofibers. As ZnO nanoparticles are known for their bioactivity, it can be concluded that these CA-PEO-ZnO composites are good candidates to be used in filtration membranes, with no loss of incorporated ZnO NPs or their release into an environment.

Green synthesis of ZnO nanoparticles decorating electrospun PAN nanofibers for enhanced radiation shielding

A comprehensive examination was conducted in our study regarding the incorporation of zinc oxide (ZnO) nanoparticles into polyacrylonitrile (PAN) nanofibers to improve their radiation protection properties. Using the electrospinning technique, ZnO nanoparticles that were synthesized via the environmentally benign ascorbic acid method were subsequently applied to PAN nanofibers. A multitude of coefficients, including the natural attenuation coefficient and mass attenuation coefficient, are pivotal in evaluating the efficacy of composite materials with regard to radiation protection. It was subjected to a comprehensive evaluation that considered a number of crucial factors: The incorporation of ZnO nanoparticles into PAN nanofiber composites leads to a substantial augmentation in the mass attenuation coefficient, which surges from 0.185 cm2/g to 0.221 cm2/g when compared to pure PAN nanofibers. Similarly, the coefficient of linear attenuation rises from 0.284 1/cm to 0.320 1/cm.

Effective attenuation of electromagnetic waves via silane surface modified zinc oxide/polybenzoxazine nanocomposites for EMI shielding application

In recent years, there has been a significant emphasis on advancing nanomaterials with exceptional properties, including high reflection loss (RL), reduced thickness, broad bandwidth, and low density. The primary goal is to augment their effectiveness in absorbing EM waves while maintaining a streamlined manufacturing process. This study, investigated the application of novel thermosetting phenolic resin as a polymeric matrix for EM shielding. Among these resins options, benzoxazine stands out due to its exceptional characteristics, which encompass facile monomer preparation through solvent-free synthesis, the absence of by-product release during polymerization, high thermal stability and superb mechanical properties. The assessement of this resin both individually and in combination with zinc oxide nanoparticles. Silanization of the nanoparticles was confirmed via Fourier transform infrared spectroscopy (FTIR). The thermal properties were investigated through differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The outcomes indicated that the incorporation of zinc oxide nanoparticles enhanced the material's stability. The thermomechanical attributes of the composites were evaluated using Dynamic Mechanical Analysis (DMA), revealing an increase in the storage modulus and a decrease in the glass transition temperature (Tg). In summary, the results from the electromagnetic tests underscore the remarkable capability of the developed composites in absorbing EM radiation, achieving highly impressive RL values of up to –50 dB. However, they exhibited acceptable shielding efficiency.

Electrophoretic Deposition of ZnO-Containing Bioactive Glass Coatings on AISI 316L Stainless Steel for Biomedical Applications

The main objective of this investigation was to study the implications of incorporating zinc oxide nanoparticles into the matrix of a bioactive glass for the bioactivity and structural properties of the deposited coating. ZnO-containing bioactive glass was coated on an AISI 316L stainless steel substrate using the electrophoretic deposition technique. AISI 316L stainless steel is a biomedical grade steel, which is widely used in different biomedical applications. For the electrophoretic deposition, voltages and times were chosen in the range of 15–40 V and 15–120 min, respectively. The microstructure, phase composition, and surface roughness of coated samples were analyzed in this investigation. Moreover, the corrosion behavior and the MTT (mitochondrial activity) of samples were studied. Results showed a uniform distribution of elements such as silicon and calcium, characteristic of bioactive glass 58S5, in the coating as well as the uniform distribution of Zn inside the ZnO-containing samples. The findings showed that the deposited ZnO-containing bioactive glass is a hydrophilic surface with a relatively rough surface texture. The results of the MTT and antibacterial effects showed that the deposited layers have promising cell viability.

Hydrogen Sulfide Removal via Sorption Process on Activated Carbon-Metal Oxide Composites Derived from Different Biomass Sources.

Biomass exploitation is a global trend due to the circular economy and the environmentally friendly spirit. Numerous applications are now based on the use of biomass-derived products. Hydrogen sulfide (H2S) is a highly toxic and environmentally hazardous gas which is emitted from various processes. Thus, the efficient removal of this toxic hazardous gas following cost-effective processes is an essential requirement. In this study, we present the synthesis and characterization of biomass-derived activated carbon/zinc oxide (ZnO@AC) composites from different biomass sources as potential candidates for H2S sorption. The synthesis involved a facile method for activated carbon production via pyrolysis and chemical activation of biomass precursors (spent coffee, Aloe-Vera waste leaves, and corncob). Activated carbon production was followed by the incorporation of zinc oxide nanoparticles into the porous carbon matrix using a simple melt impregnation method. The synthesized ZnO@AC composites were characterized using X-ray diffraction (XRD), infrared spectroscopy (IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and nitrogen porosimetry. The H2S removal performance of the ZnO@AC composites was evaluated through sorption experiments using a handmade apparatus. Our findings demonstrate that the Aloe-Vera-, spent coffee-, and corncob-derived composites exhibit superior H2S sorption capacity up to 106 mgH2S/gads., 66 mgH2S/gads., and 47 mgH2S/gads., respectively.

Genetically encoded zinc-binding collagen-like protein hybrid hydrogels for wound repair

Incorporating zinc oxide nanoparticles (ZnOnps) into collagen is a promising strategy for fabricating biomaterials with excellent antibacterial activity, but modifications are necessary due to the low zinc binding affinity of native collagen, which can cause disturbances to the functions of both ZnOnps and collagen and result in heterogeneous effects. To address this issue, we have developed a genetically encoded zinc-binding collagen-like protein, Zn-eCLP3, which was genetically modified by Scl2 collagen-like protein. Our study found that Zn-eCLP3 has a binding affinity for zinc that is 3-fold higher than that of commercialized type I collagen, as determined by isothermal titration calorimetry (ITC). Using ZnOnps-coordinated Zn-eCLP3 protein and xanthan gum, we prepared a hydrogel that showed significantly stronger antibacterial activity compared to a collagen hydrogel prepared in the same manner. In vitro cytocompatibility tests were conducted to assess the potential of the Zn-eCLP3 hydrogel for wound repair applications. In vivo experiments, which involved an S. aureus-infected mouse trauma model, showed that the application of the Zn-eCLP3 hydrogel resulted in rapid wound regeneration and increased expression of collagen-1α and cytokeratin-14. Our study highlights the potential of Zn-eCLP3 and the hybrid hydrogel for further studies and applications in wound repair.

Fabrication of Antibacterial and Antioxidant ZnO-Impregnated Amine-Functionalized Chitosan Bio-Nanocomposite Membrane for Advanced Biomedical Applications.

Developing a variety of safe and effective functioning wound dressings is a never-ending objective. Due to their exceptional antibacterial activity, biocompatibility, biodegradability, and healing-promoting properties, functionalized chitosan nanocomposites have attracted considerable attention in wound dressing applications. Herein, a novel bio-nanocomposite membrane with a variety of bio-characteristics was created through the incorporation of zinc oxide nanoparticles (ZnONPs) into amine-functionalized chitosan membrane (Am-CS). The developed ZnO@Am-CS bio-nanocomposite membrane was characterized by various analysis tools. Compared to pristine Am-CS, the developed ZnO@Am-CS membrane revealed higher water uptake and adequate mechanical properties. Moreover, increasing the ZnONP content from 0.025 to 0.1% had a positive impact on antibacterial activity against Gram-positive and Gram-negative bacteria. A maximum inhibition of 89.4% was recorded against Escherichia coli, with a maximum inhibition zone of 38 ± 0.17 mm, and was achieved by the ZnO (0.1%)@Am-CS membrane compared to 72.5% and 28 ± 0.23 mm achieved by the native Am-CS membrane. Furthermore, the bio-nanocomposite membrane demonstrated acceptable antioxidant activity, with a maximum radical scavenging value of 46%. In addition, the bio-nanocomposite membrane showed better biocompatibility and reliable biodegradability, while the cytotoxicity assessment emphasized its safety towards normal cells, with the cell viability reaching 95.7%, suggesting its potential use for advanced wound dressing applications.

The influence of forsythia essential oil and ZnO nanoparticles on the physicochemical properties of ASKG-based film and its effect on the preservation of meat quality

The non-biodegradable plastic films used for food preservation are associated with health hazards and have a negative impact on the environment, which demands the development of active films from non-toxic and antioxidant-rich bio-sources. Thus, the reported work focused on the development and characterization of Artemisia sphaerocephala Krasch. gum (ASKG)-based novel bioactive film with excellent antibacterial, antioxidant, and physicochemical properties by incorporating Zinc oxide nanoparticles (ZnONPs) and forsythia essential oil (FEO) to extend the shelf life of chicken and lamb meat. The incorporation of ZnONPs and FEO significantly increased the antioxidant and antibacterial properties of the films against Staphylococcus aureus and Escherichia coli. This addition also reduced moisture absorption (55.89–44.02%), water solubility (38.24–29.26%), moisture content (25.52–20.97%), oxygen (1.58–1.10 cm3/m2.24h.0.1 MPa) and water vapor permeability (6.67 × 10-11-4.93 × 10-11g mm-1 s-1pa-1) of the films. Moreover, the thickness, mechanical properties, thermal stability, and barrier properties against UV light were improved. The results of Fourier Transform Infrared and scanning electron microscopy demonstrated proper combination and uniform distribution of ZnONPs and FEO in the film matrix, while the X-ray diffraction study showed a new crystal phase corresponding to ZnONPs. The chicken and lamb meat samples wrapped in the active films presented significantly lower pH, total volatile basic nitrogen, thiobarbituric acid reactive substances, and total bacterial count values than the samples wrapped in the control ASKG film. The film also improved the color and maintained the texture of chicken and lamb meat during storage at 4 °C.

Sustainable Integration of Zinc Oxide Nanoparticles: Enhancing Properties of Poly(ε-Caprolactone) Electrospun Nanofibers and Cast Films

This study investigated the impact of adding zinc oxide nanoparticles (ZnO-NPs) to electrospun membranes and cast films made of poly(ε-caprolactone) (PCL). The physicochemical, mechanical, and morphological properties of the samples were analyzed. Physicochemical parameters included water contact angle (WCA), water vapor transmission rate (WVTR), permeance, water vapor permeability (WVP), light transmission (T600), and transparency (T). Mechanical properties, such as maximum stress (Ϭmax), elongation (εmax), and Young’s modulus (MPa), were also evaluated. Morphological properties were analyzed in terms of thickness, dispersion, and surface roughness (measured by the arithmetic (Ra) and quadratic (Rq) averages). The crystallinity and melting point, as well as the functional DPPH• scavenging percentage (SP%), were also studied. The results showed that adding 1 wt% ZnO-NPs improved the water barrier properties of PCL membranes and films, increasing WCA by 1%–6% and decreasing WVTR by 11%–19%, permeance by 34%–20%, and WVP by 4%–11%, respectively. The T600 values of PCL/ZnO-NPs membranes and films were 2–3 times lower than those of neat PCL samples, indicating improved optical properties. The mechanical properties of the composite membranes and films also improved, with Ϭmax increasing by 56%–32% and Young’s modulus increasing by 91%–95%, while εmax decreased by 79%–57%. The incorporation of ZnO-NPs also increased the thickness and surface roughness of the samples. The SP% of PCL/ZnO-NPs increased by almost 69%, demonstrating the beneficial effects of ZnO-NPs on the system. These findings suggest that incorporating ZnO-NPs into PCL membranes and films can enhance their properties, making them well suited for various applications, such as those within the realm of materials science and nanotechnology.

Nano-impregnation on metakaolin backbone for enhanced removal of Cu(II) and Mn(II) ions in a binary system using fixed bed column

This paper presents a comprehensive study on the synthesis and characterization of a novel composite material composed of metakaolin (MK), cellulose nanofibers (CNF), graphene oxide (GO), and zinc oxide (ZnO) for the efficient removal of heavy metals from wastewater. The main objective of this research was to enhance the removal efficiency of Cu(II) and Mn(II) ions in a binary system using a fixed bed column adsorption technique while investigating the effect of impregnating the nanomaterials. The synthesized samples were subjected to a thorough characterization using various techniques. These analyses provided insights into the structural properties and morphology of the composite material. The adsorption performance of the MK/CNF/GO/ZnO composite was evaluated through breakthrough curve analysis and kinetic modeling. The MDR model provided good fits with R2 values of 0.962 and 0.967 for Cu(II) and Mn(II) respectively. Based on the experimental breakthrough curve data, the saturation and breakthrough capacities of the composite material were calculated to be 5.97 mg/g and 4.84 mg/g for Cu(II) and Mn(II) respectively, achieved after a saturation time of 102 min for Cu(II) and 128 min for Mn(II). The results demonstrated a synergistic effect between GO and CNF, resulting in enhanced adsorption efficiency. The incorporation of ZnO nanoparticles further improved the adsorption capacity due to their high surface area, providing additional active sites for adsorption. The results showed that combining CNF, GO, and ZnO in a composite resulted in extended breakthrough and exhaustion times compared to the combination of CNF and GO alone.

Performance of bacterial nanocellulose packaging film functionalised in situ with zinc oxide: Migration onto chicken skin and antimicrobial activity

Zinc oxide nanoparticles (ZnO) are cost-effective antimicrobial agents with great potential for the active packaging industry. Bacterial NanoCellulose (BNC) features a porous fibre network, with high absorption capacity, flexible and with good mechanical properties, suitable as a carrier of active agents. In this work, BNCZnO films were developed and optimized regarding the particle size and ZnO concentration. The NaOH dropwise addition to BNC membranes immersed in Zn(CH3COO)2-PVOH enabled the production of ZnO nanoparticles with an z-average of 144 nm and a low polydispersity index. High ZnO incorporation (∼27%mZn/mBNCZnO) was obtained, with uniform distribution all over the BNC membranes. These composites were then characterized and evaluated for Zn migration using food simulants (10%, 20%, and 50% ethanol) with results lower than the limit. Migration into chicken skin, as a real food model, was low at 4 °C but exceeded the migration limit at 10 and 22 °C. Zn migration was also found to be temperature and pH dependent. When applied to chicken skin, BNCZnO was effective against E. coli, Salmonella (0.5–1.0 log reduction), and Campylobacter spp. (2.0 log reduction), indicating its potential for active packaging applications.

Novel zinc-2,6- dimethoxybenzoic acid complex as useful precursor for the synthesis of MWCNTs-ZnO nano-inorganic composite

The production of nanomaterials from new sources is an important topic because the diversity of the raw materials provides a variety of properties for these materials, therefore, this study involved the synthesis and characterization of a zinc complex obtained by reacting 2,6-dimethoxybenzoic acid (DMB) with zinc chloride in the presence of triethylamine as a bulk base. The structure and coordination mode of the resulting zinc complex were determined through various techniques, including FTIR, 1H NMR, elemental analysis, and molar conductivity. The findings confirmed that the 2,6-dimethoxybenzoic acid ligand acts as a bidentate ligand, coordinating through both oxygen atoms of the carboxylic group, resulting in a complex of the type [Zn(DMB)Cl]2. This complex was then used as a precursor for the synthesis of a ZnO-MWCNTs nanocomposite using ultrasound waves. The synthesized nanocomposite was characterized using SEM and XRD techniques. The results revealed the formation of small spherical clusters around the carbon nanotubes, with an average size of the spherical nanostructures measuring 11.875 nm. Moreover, the incorporation of zinc oxide nanoparticles had a positive impact on increasing the diameter of the carbon nanotubes from 3.005 nm to 21.218 nm.