Antibacterial Films Research Articles

Antibacterial and biodegradable food packaging film from bacterial cellulose

Antimicrobial film is becoming the - revolutionary active packaging materials for preserving food quality and extending its shelf life. Consequently, attention towards antimicrobial film is recently on the rise from food scientists for developing eco-friendly, biodegradable, and edible food packaging products over to plastic materials. Bacterial cellulose (BC), commonly known as cellulose generated from bacteria, is gaining popularity in biomedical, additive manufacturing, environmental, and food industries. As such, BC does not have antimicrobial and antioxidative properties. Therefore, researchers are fortifying BC by adding various food additive materials and ingredients to improve shelf-life, antimicrobial and antioxidant properties. Our review paper, summarized the quality parameters of BC, including tensile strength, shelf life, mechanical properties, structural properties, adhesive properties, color, surface hydrophobicity, biodegradability, and thermal stability by adding various additives. This review provides benefits for the food industry to select and produce fortified BC with enhanced shelf-life and other functional qualities. Furthermore, this report will help food scientists to develop novel food packaging materials with improved quality and eco-friendly.

A high-efficient antibacterial and biocompatible polyurethane film with Ag@rGO nanostructures prepared by microwave-assisted method: Physicochemical and dermal wound healing evaluation

Wound infections are a significant issue that can hinder the wound healing process. One way to address this problem is by enhancing the antibacterial activity of wound dressings. Accordingly, this work focuses on developing a castor-oil-based antibacterial polyurethane nanocomposite film impregnated with silver nanoparticles (AgNPs) decorated on the surface of reduced graphene oxide (rGO) nanostructures (Ag@rGO). To this aim, rGOs act as a platform to stabilize AgNPs and improve their bioavailability and dispersion quality within the PU film. The microwave-assisted synthesis of Ag@rGO nanohybrids was proved by FTIR, XRD, TGA, FE-SEM, EDS, and TEM analyses. Compared to PU/GO, the effect of Ag@rGO nanohybrids on thermo-mechanical features, morphology, antibacterial activity, cytocompatibility, and in vivo wound healing was assessed. SEM photomicrographs revealed the enhanced dispersion of Ag@rGO nanohybrids compared to GO nanosheets. Besides, according to XRD results, PU/Ag@rGO nanocomposite film demonstrated higher microphase mixing, which could be due to the finely dispersed Ag@rGO nanostructures interrupting the hydrogen bonding interactions in the hard segments. Moreover, PU/Ag@rGO nanocomposite showed excellent antibacterial behavior with completely killing E. coli and S. aureus bacteria. In vitro and in vivo wound healing studies displayed PU/Ag@rGO film effectively stimulated fibroblast cells proliferation, migration and re-epithelialization. However, the prepared antibacterial PU/Ag@rGO nanocomposite film has the potential to be used as a biomaterial for dermal wound healing applications.

Preparation and characterization of chemically modified tapioca starch-ionic liquid antibacterial films

The plasticizing and antibacterial effects of ionic liquids (ILs) in the preparation of tapioca starch-IL films were studied for the first time. 1-Ethyl-3-methylimidazolium acetate ([Emim][OAc]) caused complete disruption of starch crystallites during thermal compression, while some crystallites remained after the plasticization of starch with choline acetate ([Ch][OAc]). Compared to native tapioca starch (NTS), the plasticization of acetylated tapioca starch (ATS) and cross-linked tapioca (CTS) was slightly promoted and inhibited, respectively. Starch-[Emim][OAc] films exhibited higher hydrophobicity and mechanical properties but lower antibacterial activity than starch-[Ch][OAc] films. CTS-[Ch][OAc] films presented higher mechanical strength and antibacterial activity than NTS-[Ch][OAc] and ATS-[Ch][OAc] films. From this study, we conclude that ILs can be used in the preparation of antibacterial starch films to play the roles of plasticization and antibacterial activity. The antibacterial activity of starch films depends on types of ILs and their interactions with starch during film preparation.

Evaluation of poly(lactic acid) and ECOVIO based biocomposites loaded with antimicrobial sodium phosphate microparticles

Herein, biobased composite materials based on poly(lactic acid) (PLA) and poly(butylene adipate-co-terephthalate) (PBAT) as matrices, sodium hexametaphosphate microparticles (E452i, food additive microparticles, 1 and 5 wt%) as antimicrobial filler and acetyl tributyl citrate (ATBC, 15 wt%) as plasticizer, were developed for potential food packaging applications. Two set of composite films were obtained by melt-extrusion and compression molding, i) based on PLA matrix and ii) based on Ecovio® matrix (PLA/PBAT blend). Thermal characterization by thermogravimetric analysis and differential scanning calorimetry demonstrated that the incorporation of E452i particles improved thermal stability and crystallinity, while the mechanical test showed an increase in the Young's modulus. E452i particles also provide antimicrobial properties to the films against food-borne bacteria Listeria innocua and Staphylococcus aureus, with bacterial reduction percentages higher than 50 % in films with 5 wt% of particles. The films also preserved their disintegradability as demonstrated by an exhaustive characterization of the films under industrial composting conditions. Therefore, the results obtained in this work reveal the potential of these biocomposites as appropriated materials for antibacterial and compostable food packaging films.

Biocompatible and antibacterial poly(lactic acid)/cellulose nanofiber‑silver nanoparticle biocomposites prepared via Pickering emulsion method

Developing biocompatible and antibacterial materials with biodegradable polymers is an ideal strategy to improve public health problems and plastic pollution simultaneously. In the present study, novel biocompatible and antibacterial poly (L-lactic acid) (PLLA, coded as P)/TEMPO-oxidized cellulose nanofiber (TOCNF, coded as T)‑silver nanoparticle (AgNP, coded as A) films were first developed. The core/shell PT Pickering emulsion was prepared by sonication treatment. The TOCNF shells with –COO−Na+ groups (∼1.5 mmol/g cellulose) were used as the support to in situ synthesize and immobilize AgNPs on the PT emulsion droplets. Silver nitrate (AgNO3) (1.5, 3.0, 4.5, and 6.0 mmol/g cellulose) was added to the PT emulsions. Then, ion-exchange reaction and hydrothermal reduction were conducted to form PTA (PTA1–PTA4) emulsions. After centrifugation to remove the excess Ag+, filtration, oven-drying, and hot-pressing, the PTA composite films were successfully prepared. The PTA3 film contained AgNPs 12.4 ± 2.8 nm in diameter and exhibited the highest antibacterial activities against the E. coli (85.2%) and S. aureus (80.1%) at 37 °C, where the initial bacterial suspension concentrations were approximately 2 × 108 CFU mL−1. Therefore, the biocompatible and antibacterial PTA3 film is a promising candidate for biomedical applications, in particular as an antibacterial bioactive packaging material.

Synthesis and Characterization of Antibacterial Chitosan Films with Ciprofloxacin in Acidic Conditions.

This work presents the results of research on obtaining chitosan (CS) films containing on their surface ciprofloxacin (CIP). A unique structure was obtained that not only gives new properties to the films, but also changes the way of coverage and structure of the surface. The spectroscopic test showed that in the process of application of CIP on the surface of CS film, CIP was converted from its crystalline form to an amorphic one, hence improving its bioavailability. This improved its scope of microbiological effect. The research was carried out on the reduction of CIP concentration during the process of CIP adhesion to the surface of chitosan films. The antibacterial activity of the CS films with and without the drug was evaluated in relation to Escherichia coli and Staphylococcus aureus, as well as Candida albicans and Penicillium expansum. Changes in the morphology and roughness of membrane surfaces after the antibacterial molecule adhesion process were tested with atomic force microscopy (AFM) and scanning electron microscopy (SEM). Structural analysis of CS and its modifications were confirmed with Fourier-transform spectroscopy in the infrared by an attenuated total reflectance of IR radiation (FTIR-ATR) and solid-state nuclear magnetic resonance (NMR).

Preparation and characterizations of antibacterial and electroactive polymeric composites for wound healing applications

AbstractPolymer nanocomposites have been utilized for wound healing applications. Compared to the conventional polymer composites, conducting polymer nanocomposites comprising a blend of biocompatible polymers with electroconductive and antibacterial nanofillers such as graphene‐based nanomaterials and metal/metal oxides, have attracted great attention in this arena due to enhanced physical, electrical and biological characteristics. Herein, polyvinyl alcohol (PVA)/chitosan (CS)/graphene oxide/zinc oxide electroconductive and antibacterial composite hydrogel films were fabricated by solution casting technique, for wound healing applications. The physicochemical and conductivity studies were carried out for all the polymer samples. The successful incorporation of the nanofillers and their even distribution into the PVA‐CS matrix was validated by the scanning electron microscopy‐EDAX, x‐ray diffractometer, Fourier‐transform infrared, and Raman analytical results. An enhancement in the surface roughness of the nanofiller incorporated composite film was elucidated by the topographical images obtained from AFM analysis. The composite with higher concentration of nanofillers exhibited a maximum conductivity of 0.35 10−4 Scm−1 compared to the other fabricated composites. A good antibacterial efficacy, minimal hemolytic activity as well as better thrombogenicity were portrayed by the composite films. Additionally, the nanocomposite films exhibited no cytotoxicity and excellent cell attachment and proliferation of RAW 264.7 cells. Therefore, based on the obtained results, it can be concluded that the composite with higher particle concentration, is an ideal candidate for futuristic wound dressing applications with electroconductivity, antimicrobial activity, hemostatic ability, and biocompatibility.Highlights Fabrication of polyvinyl alcohol (PVA)/chitosan (CS)/GO‐ZnO hydrogel films by solvent‐casting A maximum conductivity of 0.35 10−4 S/cm obtained for the composite film Exhibited good antibacterial efficacy and minimal hemolytic activity Better thrombogenicity and cytocompatibility portrayed by the composite An ideal candidate for futuristic wound dressing applications

Improving antibacterial ability of Ti-Cu thin films with co-sputtering method

Due to the resistance of some bacteria to antibiotics, research in the field of dealing with bacterial infections is necessary. A practical approach utilized in this study involves the preparation of an antibacterial thin film on the surfaces, which can effectively inhibit and reduce biofilm formation and bacterial adherence. In this study, we report the fabrication of bactericidal titanium (Ti) and copper (Cu) surfaces which involves a powerful co-sputtering method. This method provides a situation in which constituent elements are deposited simultaneously to control the composition of the thin film. Prepared samples were examined by energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), X-ray diffraction (XRD), atomic force microscopy (AFM), and contact angle measurements. To evaluate antibacterial behavior, we used two bacterial strains Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus). Antibacterial activity of the prepared sample was assessed by determining the number of colony-forming units per milliliter (CFU/ml) using a standard viable cell count assay. Results indicated that as the Cu concentration increased, the nanoscale surfaces became rougher, with roughness values rising from 11.85 to 49.65 nm, and the contact angle increased from 40 to 80 degrees, indicating a hydrophilic character. These factors play a significant role in the antibacterial properties of the surface. The Ti-Cu films displayed superior antibacterial ability, with a 99.9% reduction (equivalent to a 5-log reduction) in bacterial viability after 2 h compared to Ti alone against both bacterial strains. Field emission scanning electron microscopy (FE-SEM) images verified that both E. coli and S. aureus cells were physically deformed and damaged the bacterial cell ultrastructure was observed. These findings highlight that adding Cu to Ti can improve the antibacterial ability of the surface while inhibiting bacterial adherence. Therefore, the Ti14-Cu86 sample with the highest percentage of Cu had the best bactericidal rate. Investigation of toxicity of Cu-Ti thin films was conducted the using the MTT assay, which revealed their biocompatibility and absence of cytotoxicity, further confirming their potential as promising biomaterials for various applications.

Enhanced antibacterial properties of poly(butylene succinate-co-terephthalate)/Ag@MgO nanocomposite films for food packaging

The Ag@MgO nanoparticles (NPs), consisting of silver NPs with a size range of 6–15 nm well-dispersed on the surface of MgO nanoparticles, were synthesized using a simple and efficient in situ synthesis method. These NPs exhibited superior antibacterial activity compared to bare MgO NPs. Subsequently, they were incorporated into poly(butylene succinate-co-terephthalate) (PBST) matrix to prepare antibacterial food packaging films. The effects of Ag@MgO NPs morphology on the compatibility, mechanical, water vapor barrier, UV blocking and antibacterial properties of PBST matrix were evaluated. Unmodified Ag@MgO NPs caused agglomeration and poor mechanical properties. However, when the Ag@MgO NPs were surface modified and interacted with the PBST matrix, the dispersion of nanoparticles and crystallinity improved, resulting in enhanced tensile strength and barrier properties of the composite films. Furthermore, the well-formed of Ag@MgO NPs in the films played a positive role in controlling the growth of microorganisms. Upon incorporation of the modified Ag@MgO NPs, the PBST nanocomposite films exhibited a 23.5% increase in the tensile strength and a 63% decrease in the water vapor permeability compared to PBST films. Moreover, the UV blocking performances were enhanced, and high antibacterial rates of 99.8% and 99.7% were achieved against E. coli and S. aureus, respectively. All the results indicate that the PBST incorporating modified Ag@MgO NPs have excellent potential for use in food packaging applications.

Apigenin@ZIF-8 with pH-responsive sustained release function added to propolis-gelatin films achieved an outstanding antibacterial effect

Packaging films containing antibacterial substances play a crucial role in controlling contamination caused by food-borne pathogens. Herein, apigenin (APG) was encapsulated in zeolitic imidazolate frameworks 8 (ZIF-8) to achieve a synergistic antibacterial effect and prolonged drug release, aiming to extend the shelf life of food products. Under acidic condition, the release rate of APG reached 73.70 % after 12 h. Subsequently, propolis-gelatin (PG) films were prepared for food packaging. The addition of APG@ZIF-8 enhanced the hydrophobicity of PG films, making them more suitable for food packaging. However, the composite film exhibited reduced damage resistance and flexibility. The composite films demonstrated 100 % inhibition against Staphylococcus aureus and Escherichia coli under appropriate amount of APG@ZIF-8. The composite film coating significantly reduced the bacteria count on apple surfaces by 99.95% during storage, while maintaining their appearance. This study provides an effective way to develop novel antibacterial composite films.

Ag-lignin hybrid nanoparticles for high-performance solar absorption in photothermal antibacterial chitosan films

There is an urgent need for antimicrobial films based on sustainable resources and production methods. In this study, we present a bio-based nanocomposite film composed of chitosan (∼60 wt%), lignin nanoparticles (LNPs, ∼40 wt%), a small amount of glutaraldehyde (1.5 wt%), and a trace level of silver nanoparticles (AgNPs, 0.072 wt%). The uniform dispersion with LNPs prevented aggregation of metallic silver, resulting in small (diameter 3.3nm) AgNPs. The nanocomposite film absorbs 89% of radiation across the entire solar spectrum and exhibits a remarkable photothermally triggered antibacterial effect, which is further enhanced by the dark color of lignin. Under simulated solar light illumination, the nanocomposite films demonstrated a significant reduction in viable Escherichia coli count compared to control scenarios. The potential applications of these nanocomposites extend to sunlight-activated antimicrobial films and coatings, addressing the growing demand for sustainable and effective antimicrobial materials.

Preparation and antimicrobial properties of polymer blend based on LLDPE and polyhexamethylene guanidine

AbstractAntibacterial packaging represents an active packaging solution crafted to uphold the quality and safety of products. One of the popular polymer used in food packaging is Linear Low‐Density Polyethylene (LLDPE), due to its low cost, ease of processing, and high mechanical properties. Polymer blend based on LLDPE and antibacterial agent PHMG were prepared in the presence of PE‐g_AM compatibilizer and DCP initiator. The inclusion of PHMG resulted in a decline in the material's tensile strength. Specifically, in the sample containing 2% PHMG content, the tensile strength decreased by 11.6% in comparison to the original PE; whereas the elongation at break of the samples slightly increased. IR analysis confirmed the presence of characteristic groups of PHMG after the reaction. The polymer blend material acquired demonstrated antibacterial effects against both Gram‐negative (E. coli) and Gram‐positive (S. aureus) bacteria owing to the existence of PHMG within the material. The polymer blend sample LLDPE/2%PHMG/0.2%DCP/5%PE‐g_AM demonstrated the best antibacterial effect. The diameter of the S. aureus resistant zone reached 1.9 cm, 2.4 times bigger than the those of E. coli. The obtained properties of mechanical properties and antibacterial ability, polymer blend based on LLDPE/PHMG is suitable for application of antibacterial packaging film.

Smart antibacterial nanocellulose packaging film based on pH-stimulate responsive microcapsules synthesized by Pickering emulsion template

Spoilage results in food waste and endangers consumer health, and the smart antibacterial packaging can effectively inhibit bacterial growth and reduce food spoilage. In this study, the smart antibacterial nanocellulose packaging films were developed by adding the pH-stimulated responsive microcapsules into cellulose nanofibril (CNF) film-forming. The microcapsules were synthesized by interfacial polymerization of Pickering emulsion. Carboxylated cellulose nanocrystals as solid particles stabilized the composited oil phase to prepare the oil-in-water Pickering emulsion. The emulsion with the particle concentration of 1.25 wt% and the oil phase mass fraction of 7.5 % processes excellent stability and uniform particle size, was chosen to synthesize microcapsules. The cinnamaldehyde in the film with the addition amount of microcapsules 0.6 g burst released in the first 1 h and then slowly, and the cumulative release at pH 2.0, 4.0, 5.5 and 7.2 was 28.43 μg/cm2, 18.84 μg/cm2, 16.52 μg/cm2 and 12.89 μg/cm2, respectively. The inhibitory rate of film against both E. coli and L. monocytogenes reached 99 % at pH 4.0. The shelf life of pork packed by the film prolonged to nearly 9 d at room temperature. The developed films have the potential to be used in food packaging.

An Overview of Polymer Composite Films for Antibacterial Display Coatings and Sensor Applications.

The escalating presence of pathogenic microbes has spurred a heightened interest in antimicrobial polymer composites tailored for hygiene applications. These innovative composites ingeniously incorporate potent antimicrobial agents such as metals, metal oxides, and carbon derivatives. This integration equips them with the unique ability to offer robust and persistent protection against a diverse array of pathogens. By effectively countering the challenges posed by microbial contamination, these pioneering composites hold the potential to create safer environments and contribute to the advancement of public health on a substantial scale. This review discusses the recent progress of antibacterial polymer composite films with the inclusion of metals, metal oxides, and carbon derivatives, highlighting their antimicrobial activity against various pathogenic microorganisms. Furthermore, the review summarizes the recent developments in antibacterial polymer composites for display coatings, sensors, and multifunctional applications. Through a comprehensive examination of various research studies, this review aims to provide valuable insights into the design, performance, and real-time applications of these smart antimicrobial coatings for interactive devices, thus enhancing their overall user experience and safety. It concludes with an outlook on the future perspectives and challenges of antimicrobial polymer composites and their potential applications across diverse fields.

Antibacterial properties and mechanism of nanometer zinc oxide composites

Nanometer zinc oxide (nano ZnO) is frequently added as an antibacterial agent to matrix materials used widely in packaging applications such as food. Two antibacterial films were prepared with high antibacterial activity achieved through low doping: ZnO/linear low-density polyethylene (ZnO/LLDPE) and ZnO/polycarbonate (ZnO/PC). The antibacterial rates of both films against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were greater than 99.9 %, and their antibacterial performance value (R) was ≥ 5.9. Experiments were conducted using LLDPE and PC with varying chain mobility to verify that the commonly known three antibacterial mechanisms, namely soluble Zn2+ ions, reactive oxygen species (ROS), and direct contact between nano ZnO and bacteria, are not the primary mechanisms responsible for the antibacterial properties of the nano ZnO composite film. Furthermore, a new mechanism of inhibiting bacteria by nano ZnO irradiated photons was proposed to explain the high antibacterial rate of ZnO/PC films under the condition of limited nano ZnO migration. Understanding the antibacterial mechanism of nano ZnO in polymers will aid in the development of ZnO antibacterial agents that can effectively exert high antibacterial effects in matrix materials.

Furoic acid-mediated konjac glucomannan/flaxseed gum based green biodegradable antibacterial film for Shine-Muscat grape preservation

Considering the growing threats to the environment and human health, such as plastic pollution and food spoilage, the development of naturally antibacterial food packaging materials with biodegradable capabilities has recently attracted considerable attention. This work applies the concept of green environmental protection to packaging technology, and a new type of green edible antibacterial packaging film was developed. The basic idea is to incorporate furoic acid (FA), which possesses excellent antibacterial activity, into the flaxseed gum and konjac glucomannan matrix (FK) as a filler to obtain a series of FK-FA bioactive films. This incorporation simultaneously improves the hydrophobicity and UV-barrier ability by 12.28 % and 42.87 %, respectively. Meanwhile, the diameters of the antibacterial zone of the FK-FA0.4% films (composite FK films containing 0.4 % FA) against E. coli and S. aureus increased to 38.98 mm and 36.29 mm from 24.00 mm of pure FK film, respectively. As a consequence, the grape sample sealed with FK-FA0.4% film remained edible on the 18th day of storage, while those packaged with commercial PE film and pure FK were seriously rotted and lost edible value on the 12th day, further confirming the enhanced preservation capacity. Finally, the as-prepared films were established to be biodegradable and were almost completely degraded within 25 days under simulated environmental conditions. Overall, these promising results show the potential of FK-FA films for replacing plastic packaging materials as eco-friendly edible films with prolonged shelf life for active packaging.

Supramolecular and double network strategy toward strong and antibacterial protein films by introducing waterborne polyurethane and quaternized chitosan

Plant-derived protein composite film is one of the promising substitutes for non-renewable petroleum-based materials. However, its application is greatly limited due to the low mechanical strength and poor antibacterial activity. In this paper, a dual network strategy based on supramolecular chemistry was reported for fabricating a high-strength and antibacterial soybean protein (SP)-based biofilm by incorporating waterborne polyurethane (WP) and quaternized chitosan (QCS). Specifically, castor oil as a renewable plant resource was used for the preparation of functional WP polymer. Based on the synergistic effect of WP network and SP network, the performance of SP-based composite film was significantly enhanced. Compared with the original SP film, the tensile strength and toughness of SP/WP/QCS film were substantially increased by 159% and 531%, respectively. In addition, the composite film showed significantly enhanced water resistance and UV shielding capability. Due to the antibacterial effect of the quaternary ammonium salt component, the SP/WP/QCS composite film exhibited superior antibacterial properties. Therefore, this study provides a feasible strategy for the preparation of high-performance SP-based films, which is expected to be applied in packaging, multifunctional adhesive, and UV-shielding coating.

TEMPO-oxidized nanocellulose immobilized AgNPs modified chitosan composite film with durable antibacterial and preservative properties for fruits and vegetables package

Film preservative packaging is one of common techniques to solve rot problem of fruits and vegetables in transit, storage and sale process. But traditional petroleum-based films have no long-lasting antibacterial properties and they are difficult to biodegrade. Herein, TEMPO-oxidized nanocellulose (TCNF) was used as green reducer and stabilizer to synthesize and immobilize silver nanoparticles (AgNPs) in one-pot method. Next the TCNF immobilized AgNPs was combined with chitosan to form antibacterial preservative composite film (CS/TCNF@AgNPs). The results show that CS/TCNF@AgNPs exhibited satisfied preservative effects for cherry tomatoes and strawberries. Notably, the composite film showed excellent antibacterial properties against E. coli and S. aureus and the accumulated release amount of AgNPs was only about 2.05% after 264 h. Furthermore, the composite film degraded almost completely in soil within 25 days. The cytotoxicity assay also exhibited favorable biocompatibility. Therefore, the composite film has potential application as a packaging material for fruit and vegetable antibacterial preservation.

Nanotextured surfaces with iron oxide and titania for antibacterial and water purification applications via supersonic spraying

Microbial infections pose a significant threat to public health worldwide. Antibacterial treatments are required to prevent bacterial contamination and protect public health. Herein we supersonically sprayed iron and titania NPs which are nontoxic earth-abundant and low-cost antibacterial materials to fabricate Fe2O3/TiO2-based antibacterial hybrid films capable of inhibiting E. coli by up to 100% upon ultraviolet (UV) light irradiation. The supersonically sprayed iron and titania NPs were annealed to prepare Fe2O3/TiO2-based metal oxide nanosheets. The photomobilized electrons and holes generated superoxide anions and hydroxyl radicals respectively via reduction and oxidation. The bare Fe2O3-based and hybrid Fe2O3/TiO2-based films were photoactivated via visible and UV lights and exhibited E. coli inhibition rates of 42.1% and 99.9% respectively. In addition the hybrid Fe2O3/TiO2-based films were superhydrophilic which promoted the strong adhesion of bacteria-contaminated aerosols between the surrounding atmosphere and films. The water-purification capability of the films was confirmed by the efficient photodegradation of a methylene blue solution upon UV irradiation.

Preparation of robust, water-resistant, antibacterial, and antioxidant chitosan-based films by incorporation of cinnamaldehyde-tannin acid-zinc acetate nanoparticles.

Chitosan (CS) films have poor mechanical property, low water-resistance and limited antimicrobial activity, which hinder their application in food preservation industry. Cinnamaldehyde-tannic acid-zinc acetate nanoparticles (CTZA NPs) assembled from edible medicinal plant extracts were successfully incorporated into CS films to solve these issues. The tensile strength and water contact angle of the composite films increased about 5.25-fold and 17.55°. The addition of CTZA NPs reduced the water sensitivity of CS films, which could undergo appreciable stretching in water without breaking. Furthermore, CTZA NPs significantly enhanced the UV adsorption, antibacterial, and antioxidant properties of the films, while reduced their water vapor permeability. Moreover, it was possible to print inks onto the films because the presence of the hydrophobic CTZA NPs facilitated the deposition of carbon powder onto their surfaces. The films with great antibacterial and antioxidant activities can be applied for food packaging application.