In situ self-assembly of pulp microfibers and nanofibers into a transparent, high-performance and degradable film.

Despite the significant properties of fossil plastics, the current unsustainable methods employed in production, usage and disposal present a grave threat to both energy and environment. The development of degradable biomass materials as substitutes for fossil plastics can effectively address the energy-environment paradox at the source. Here, we prepared novel micro-nano multiscale composite films through assembling and crosslinking nanocellulose with coniferous wood pulp microfibers. The composite film combines the advantages of microfibers and nanocellulose, achieving a maximum transmittance of 91 %, foldability, excellent mechanical properties (tensile strength: 51.3 MPa, elongation at break: 4 %, young's modulus: 3.4 GPa), high thermal stability and complete degradation within 40 days. The composite film exhibits mechanochemical self-healing and retains properties even after fracture. Such exceptional performance fully meets the requirements for substituting petroleum plastics. By incorporating CaAlSiN3:Eu2+ into the composite film, it enables dual emission of red and blue light, thereby being able to promote plant growth and presenting potential as a novel sustainable alternative for agricultural films. By assembling microfiber and nanocellulose, such novel strategy is presented for the fabrication of high-quality biomass materials, thereby offering a promising avenue towards environment-friendly resource-sustainable new materials.

Improved moisture barrier and mechanical properties of rice protein/sodium alginate films for banana and oil preservation: Effect of the type and addition form of fatty acid.

Attenuating the moisture sensitivity of hydrophilic protein/polysaccharide-based films without impairing other properties remains a challenge. Fatty acid dispersed in Pickering emulsion was proposed to overcome such issue. An increase in fatty acid chain length slightly reduced the water vapor permeability (WVP) of emulsion films. As the number of fatty acid double bonds increased from 0 to 1, the WVP of emulsion films was significantly decreased by 14.02% while mechanical properties were significantly enhanced. More hydrogen bonds and stronger electrostatic interactions in the presence of fatty acids were observed by molecular dynamics simulation. The weight loss of bananas coated with oleic acid-incorporated film-forming emulsion was 6.81% lower than that of uncoated group after 4 days, and the corresponding film was more effective to delay oil oxidation than the commercial polypropylene film, indicating that the film is a promising alternative to food coating and packaging material.

Preparation and Electrochromic Properties of MnO2/PPy Composite Films with Coral-like Structures.

MnO2/polypyrrole (PPy) composite films were deposited on fluorine-doped tin oxide (FTO) conductive glasses by a two-step wet-chemical method, including electrochemical deposition and chemical bath deposition (CBD). The porous MnO2 films were first grown on FTO glasses by an electrodeposition method. Second, polypyrrole nanoparticles were polymerized by the oxidation-reduction reaction between MnO2 and pyrrole, using the presynthesized MnO2 as the skeleton. Then, MnO2/PPy composite films with coral-like structures were obtained. The electrochemical and electrochromic (EC) properties of the prepared films were investigated. The results show that, compared to the single MnO2 or PPy film, the MnO2/PPy composite film has a larger optical modulation (67.3% at a wavelength of 900 nm), faster response times (4 s for coloration and 3 s for bleaching), and a higher coloration efficiency (218.16 cm2·C-1). The high coloration efficiency attests to the exceptional performance of the composite film in converting electrical signals into vivid color changes. The electrochemical stability test results show that the composite film maintains a stable EC performance after 200 coloration/bleaching cycles. The coral-like structures of the composite film are responsible for the better EC properties.

An antibacterial film using κ-carrageenan loaded with benzyl isothiocyanate nanoemulsion: Characterization and application in beef preservation.

Benzyl isothiocyanate (BITC) is a naturally active bacteriostatic substance and κ-carrageenan (KC) is a good film-forming substrate. In the present study, a nanoemulsion incorporating BITC was fabricated with a particle size of 224.1 nm and an encapsulation efficiency of 69.2 %. Subsequently, the acquired BITC nanoemulsion (BITC-NE) was incorporated into the KC-based film, and the light transmittance of the prepared composite films was lower than that of the pure KC film. Fourier transform infrared spectroscopy and scanning electron microscopy revealed that BITC-NE was compatible with the KC matrix. BITC-NE incorporation enhanced the tensile strength of the KC-based films by 33.7 %, decreased the elongation at break by 33.8 %, decreased the water vapor permeability by 60.1 %, increased the maximum thermal degradation temperature by 48.8 %, and decreased the oxygen permeability by 42 % (p < 0.05). Furthermore, the composite films showed enhanced antimicrobial activity against Staphylococcus aureus, Salmonella typhimurium, and Pseudomonas fluorescens. The developed KC-based composite films were applied to wrap raw beef, which significantly delayed the increase in total viable count, total volatile base nitrogen content, and thiobarbituric acid reactive substances, and prolonged the shelf-life of the raw beef by up to 10 days. These results indicated that the composite films prepared by incorporating BITC nanoemulsions into KC matrices have great antimicrobial application potential.

Development of multifunctional chitosan-based composite film loaded with tea polyphenol nanoparticles for strawberry preservation.

Incorporating polysaccharide-based composite films with nanobiotechnology offers a new strategy for food preservation. This study initially focuses on the preparation of tea polyphenol nanoparticles (TPNP), novel and derived from natural antibacterial agents, which serve to improve stability. Afterwards chitosan-based composite films loaded with TPNP (CTN film) were developed using solution casting method. The incorporation of TPNP significantly improved the UV/water/oxygen barrier properties, mechanical properties and thermal stability, alongside notable physical properties including water contact angle (93.65 ± 0.04°), low water vapor permeability (33.72 ± 3.32 g/m2h) and oxygen permeability (0.11 ± 0.02 g/m2h), tensile strength (61.83 ± 0.70 %), and elongation at break (31.60 ± 6.12 %). The CTN film not only exhibited exceptional biodegradability and nontoxicity, but also demonstrated remarkable antimicrobial efficacy against Escherichia coli and Bacillus subtilis. Additionally, it showcased potent antioxidant activity, boasting DPPH and ABTS radical scavenging rates up to 89.25 ± 0.18 % and 93.84 ± 0.42 %. The CTN film was successfully formed on the surface of strawberries through dip-coating process and their shelf life was extended from 4 to 6 days at 20 °C without side-effect on the weight loss, harness, pH and total soluble solids, illustrating its potential for enhancing food preservation.

Preparation, characterization, and application of gallic acid-mediated photodynamic chitosan-nanocellulose-based films.

In this study, an active film composed of gallic acid (GA), chitosan (CS), and cellulose nanocrystals (CNC) was prepared using a solution casting method and synergistic photodynamic inactivation (PDI) technology. Characterization of the film showed that the CS-CNC-GA composite film had high transparency and UV-blocking ability. The addition of GA (0.2 %-1.0 %) significantly enhanced the mechanical properties, water resistance, and thermal stability of the film. The tensile strength increased up to 46.30 MPa, and the lowest water vapor permeability was 1.16 × e-12 g/(cm·s·Pa). The PDI-treated CS-CNC-GA1.0 composite film exhibited significantly enhanced antibacterial activity, with inhibition zone diameters of 31.83 mm against Staphylococcus aureus and 21.82 mm against Escherichia coli. The CS-CNC-GA composite film also showed good antioxidant activity. Additionally, the CS-CNC-GA1.0 composite film generated a large amount of singlet oxygen under UV-C light irradiation. It was found that using the CS-CNC-GA1.0 composite film for packaging and storage of oysters at 4 °C effectively delayed the increase in pH, total colony count, and lipid oxidation in oysters. In conclusion, the CS-CNC-GA composite film based on PDI technology has great potential for applications in the preservation of aquatic products.

Influence of electrodeposition parameters on the fabrication of Ni-Co/SiC + TiN composite films through pulse current electrodeposition.

In this investigation, pulsed current electro-deposition (PCE) was used to prefabricate Ni-Co/SiC + TiN composite coatings (NCSTCCs) on mild steel surfaces. The research focused on the influence of two electrodeposition parameters, pulse frequency (PF) and duty cycle (DC), on NCSTCF features including microscopic surface morphology, crystal orientation, grain size, microhardness, SiC and TiN nanoparticles (NPs), deposition quantity, and corrosion resistance properties. The results indicated that NCSTCCs produced under a 10% DC showed minimal SiC and TiN contents with a percent volume of just 5.6 v/v% and 5.4 v/v% respectively under the fixed condition of 60 Hz PF. However, the three-dimensional surface diagram indicated that the Ni-Co/SiC + TiN composite film deposited at 50% DC and 10 Hz PF displayed the highest SiC and TiN contents (11.6 v/v% and 11.7 v/v%) among all the films. Furthermore, NCSTCCs deposited under 50% DC and 10 Hz PF had peak microhardness at 667.4 kg/mm2, while the composite film achieved a microhardness of 514.1 kg/mm2 when prepared using 10% DC and 60 Hz PF. Moreover, when the DC and PF were at 50% and 10 Hz respectively, the Ni-Co/SiC + TiN composite film presented the maximum charge transfer resistance (4915.7-4927.2 Ω·cm2), indicating an excellent corrosion resistance.

RGO/CuCl-Based Flexible Gas Sensor for High-Concentration Carbon Monoxide Gas Detection at Room Temperature.

Carbon monoxide (CO) gas sensors are widely used, especially for environmental monitoring in confined spaces such as the landscape of mining cave ruins in mining parks, which is essential for ensuring the health and safety of tourists and staff. In this paper, a flexible CO gas sensor based on polyimide, interdigital electrodes, and reduced graphene oxide (RGO)/cuprous chloride (CuCl) composite film is designed and manufactured for reliable room temperature detection of high-concentration CO gas. The structure size of RGO/CuCl gas-sensitive film is 5 × 5 mm. The RGO with a 62.65% C-C bond is prepared by the thermal reduction method. The test results show that the sensor has a high response in the range of 400-2000 ppm CO gas concentration, and the maximum response is 1.56. The linear correlation coefficient of the sensor is 0.981, which indicates that the sensor has good output response characteristics. The response time of the sensor for 400 ppm CO gas is 332 s, which indicates that the sensor has a fast response rate. Furthermore, compared with other gases, the sensor shows higher gas selectivity for CO gas. This sensor has the characteristics of small size and easy attachment; therefore, it can be installed on the shoulder or helmet of tourists' safety suits, providing personalized real-time warning prompts for tourists' physical health status.

Preparation of the double cross-linking carbon dots-polyvinyl alcohol-carboxymethyl cellulose composite film for food active packaging application.

This paper prepared a new kind of carbon dots-polyvinyl alcohol-carboxymethyl cellulose composite film with antibacterial properties. Carbon dots and citric acid were used as cross-linking agents, and polyvinyl alcohol and carboxymethyl cellulose were used as matrices respectively. The mechanical properties, UV shielding performance, thermal stability, antioxidant capability, and antibacterial activities of the carbon dots-polyvinyl alcohol-carboxymethyl cellulose composite film were researched. The prepared carbon dots-polyvinyl alcohol-carboxymethyl cellulose composite film was applied in the strawberry freshness preservation test. And test results indicated that the carbon dots-polyvinyl alcohol-carboxymethyl cellulose composite film could prevent rotting and extend the shelf life of strawberries. This carbon dots-polyvinyl alcohol-carboxymethyl cellulose composite film could be applied in the food active packaging field.

Changes in Current Transport and Regulation of the Microstructure of Graphene/Polyimide Films under Joule Heating Treatment.

The excellent electrical properties of graphene have received widespread attention. However, the difficulty of electron transfer between layers still restricts the application of graphene composite materials to a large extent. Therefore, in this study, graphene/polyimide films were subjected to a Joule heating treatment to improve the electrical conductivity of the film by ~76.85%. After multiple Joule thermal cycle treatments, the conductivity of the graphene/polyimide film still gradually increased, but the increase in amplitude tended to slow down. Finally, after eight Joule heat treatments, the conductivity of the graphene/polyimide film was improved by ~93.94%. The Joule heating treatment caused the polyimide to undergo atomic rearrangement near the interface bonded to the graphene, forming a new crystalline phase favourable for electron transport with graphene as a template. Accordingly, a model of the bilayer capacitive microstructure of graphene/polyimide was proposed. The experiment suggests that the Joule heating treatment can effectively reduce the distance between graphene electrode plates in the bilayer capacitive micro-nanostructures of graphene/polyimide and greatly increases the number of charge carriers on the electrode plates. The TEM and WAXS characterisation results imply atomic structure changes at the graphene/polyimide bonding interface.

Using celluloses to reinforce the optimized alginate film in wet state: Effect of cellulose types and cooking treatment.

Alginate (Alg) as co-extruded casing is of interest to the meat industry as replacers for natural sausage casing. However, these studies on the mechanical reinforcement of Alg-based film are still limited in the wet state (e.g. co-extrusion process). In this work, Alg-D with the highest viscosity-average molecular weight (1.12 × 105) was selected from four types of alginates based on the results of the viscosity of Alg solutions and film strength. Next, three celluloses (cellulose nanocrystals (CNC), cellulose nanofibers (CNF) and microfibrillated fiber (MFC)) were added to the Alg-D matrix at different concentrations. SEM showed that the cross section of the Alg-based films became more compact and uniform when the size of celluloses decreased. The tensile test revealed that the strength (TS) of Alg-based films exhibited an initial increase followed by a subsequent drop as the cellulose content rose. The best mechanical strengthening effect was the Alg-CNC film (1.16 MPa), which increased by 93.33 % compared with that of pure Alg. Cooking treatment could further enhance this trend. The opacity increased gradually with the increase of cellulose content, while these films were still transparent enough for food packaging. These findings would have potential applications in food packaging, especially co-extruded sausage casings.

Effect of Poly(propylene carbonate) on Properties of Polylactic Acid-Based Composite Films.

To enrich the properties of polylactic acid (PLA)-based composite films and improve the base degradability, in this study, a certain amount of poly(propylene carbonate) (PPC) was added to PLA-based composite films, and PLA/PPC-based composite films were prepared by melt blending and hot-press molding. The effects of the introduction of PPC on the composite films were analyzed through in-depth studies on mechanical properties, water vapor and oxygen transmission rates, thermal analysis, compost degradability, and bacterial inhibition properties of the composite films. When the introduction ratio coefficient of PPC was 30%, the tensile strength of the composite film increased by 19.68%, the water vapor transmission coefficient decreased by 14.43%, and the oxygen transmission coefficient decreased by 18.31% compared to that of the composite film without PPC, the cold crystallization temperature of the composite film increased gradually from 96.9 °C to 104.8 °C, and PPC improved the crystallization ability of composite film. The degradation rate of the composite film with PPC increased significantly compared to the previous one, and the degradation rate increased with the increase in the PPC content. The degradation rate was 49.85% and 46.22% faster on average than that of the composite film without PPC when the degradation was carried out over 40 and 80 days; the composite film had certain inhibition, and the maximum diameter of the inhibition circle was 2.42 cm. This study provides a strategy for the development of PLA-based biodegradable laminates, which can promote the application of PLA-based laminates in food packaging.

MXene@c-MWCNT Adhesive Silica Nanofiber Membranes Enhancing Electromagnetic Interference Shielding and Thermal Insulation Performance in Extreme Environments.

A lightweight flexible thermally stable composite is fabricated by combining silica nanofiber membranes (SNM) with MXene@c-MWCNT hybrid film. The flexible SNM with outstanding thermal insulation are prepared from tetraethyl orthosilicate hydrolysis and condensation by electrospinning and high-temperature calcination; the MXene@c-MWCNTx:y films are prepared by vacuum filtration technology. In particular, the SNM and MXene@c-MWCNT6:4 as one unit layer (SMC1) are bonded together with 5 wt% polyvinyl alcohol (PVA) solution, which exhibits low thermal conductivity (0.066 W m-1 K-1) and good electromagnetic interference (EMI) shielding performance (average EMI SET, 37.8 dB). With the increase in functional unit layer, the overall thermal insulation performance of the whole composite film (SMCx) remains stable, and EMI shielding performance is greatly improved, especially for SMC3 with three unit layers, the average EMI SET is as high as 55.4 dB. In addition, the organic combination of rigid SNM and tough MXene@c-MWCNT6:4 makes SMCx exhibit good mechanical tensile strength. Importantly, SMCx exhibit stable EMI shielding and excellent thermal insulation even in extreme heat and cold environment. Therefore, this work provides a novel design idea and important reference value for EMI shielding and thermal insulation components used in extreme environmental protection equipment in the future.

Properties and release behavior of sodium alginate-based nanocomposite active films: Effects of particle size of IRMOF-3.

Nanoparticles are used as fillers to improve the properties of biopolymers, and their particle size is an important parameter. This work aims to investigate the effect of particle size of isoreticular metal-organic framework-3 (IRMOF-3) on the mechanical, physical, and release properties of sodium alginate (SA)-based composite active film. In our study, IRMOF-3 with six different particle sizes was synthesized by introducing additives. IRMOF-3 loading with carvacrol (IRMOF-3/CA nanoparticles) was incorporated into the SA matrix to prepare the composite film. The characterization and testing results of films showed that the particle size of nanoparticles affected the physical morphology and chemical structure of the film. Especially smaller nanoparticles uniformly dispersed into the SA matrix more easily, forming a denser and more stable spatial network structure with SA, which could more significantly improve the tensile strength, water vapor barrier, and hydrophobic properties of the film (P < 0.05). In addition, the CA release rate from the active film could be significantly reduced by about 33.90 % even when the smallest particle size of the IRMOF-3/CA nanoparticles was added. Therefore, when IRMOF-3/CA is used as the nano-filler to develop SA-based active film, its particle size has a potential influence on the properties of the film.

Preservation of chilled beef using active films based on bacterial cellulose and polyvinyl alcohol with the incorporation of Perilla essential oil Pickering emulsion.

In this study, Perilla essential oil (PEO) Pickering emulsions, prepared using soybean protein isolate-chitosan nanoparticles (SPI-CSNPs) as emulsifiers (SCEO), were used to improve the performance of bacterial cellulose/polyvinyl alcohol (BC/PVA) films for application in chilled beef preservation. The SCEO has a smaller particle size (185 nm), higher viscosity, a more uniform dispersion and was more stable at an oil phase volume fraction of 80 %. An increase in the films' surface roughness and in the hydrogen bonding between SCEO and the films' matrix was also observed, resulting in a lower tensile strength (TS, 94.75-62.02 MPa) and higher elongation at break (EAB, 26.78-55.62 %). Moreover, the thermal stability, water vapor permeability, antioxidant and antibacterial properties of the composite films improved as the SCEO content increased. Furthermore, the Pickering emulsion method was effective in preventing the loss of PEO during storage. Overall, one particular composite film, BP/SCEO3, could prolong the shelf life of chilled beef by up to 14 days, and hence was promising for food preservation.

Production of PLA/cellulose derived from pineapple leaves as bio-degradable mulch film.

Mulch films were fabricated from polylactic acid (PLA) with cellulose nanocrystals (PNC) extracted from pineapple leaves. The PNC was modified by incorporating 4 wt% triethoxyvinylsilane (TEVS), designated as 4PNC, to enhance its interaction with PLA. The films incorporated varying concentrations of PNC (1, 2, 4, and 8 wt%). The results indicated that higher PNC concentrations increased the water vapor permeability (WVP) and biodegradability of the composite films, while reducing light transmission. Films containing 4PNC, particularly at 4 wt% (PLA/4PNC-4), exhibited an 11.18 % increase in elongation at break compared to neat PLA films. Moreover, these films showed reduced light transmission, correlating with decreased weed growth, reduced WVP, and enhanced barrier properties, indicative of improved soil moisture retention. Additionally, PLA films with 4PNC demonstrated greater thermal degradation stability than those with unmodified PNC, suggesting enhanced heat resistance. However, there was no significant difference in aerobic biodegradation between the PLA films with PNC and those with 4PNC. This study confirms that TEVS-modified cellulose significantly enhances the properties of bio-composite films, making them more suitable for mulch film applications.

Multi-strategy dynamic cross-linking to prepare EGCG-loaded multifunctional Pickering emulsion/α-cyclodextrin/konjac glucomannan composite films for ultra-durable preservation of perishable fruits.

Developing multifunctional films with antibacterial, antioxidant, and sustained-release properties is a robust strategy for preventing contamination of perishable fruits by foodborne microorganisms. This study engineered a sustained-release biodegradable antibacterial film loaded with EGCG (Pickering emulsion (PE)/α-Cyclodextrin (α-CD)/Konjac glucomannan (KGM)) through multi-strategy cross-linking for fruit preservation. EGCG is stabilized using PE and incorporated into the α-CD/KGM inclusion compound; the unique structure of α-CD enhances EGCG encapsulation, while KGM provides the film toughness and surface adhesion. The composite film's physicochemical properties, antioxidant, bacteriostatic and biodegradability were studied. Results showed that Pickering emulsions with 3 % oil phase exhibited excellent stability. Moreover, α-CD introduction increased the loading and sustained release of EGCG from the film, and its concentration significantly affected the light transmission, thermal stability, mechanical strength, mechanical characteristics and antioxidant capacity of the composite membrane. Antioxidant and antimicrobial activities of the composite film increased significantly with increasing α-CD concentration. Application of the film to tomatoes and strawberries effectively inhibited Escherichia coli and Staphylococcus aureus growth, prolonging the shelf-life of the fruits. Notably, the composite film exhibits superior biodegradability in soil. This EGCG-loaded PE/α-CD/KGM composite film is anticipated to be a multifunctional antimicrobial preservation material with sustained-release properties and biodegradable for perishable food applications.

Enhancing Mechanical and Antimicrobial Properties of Dialdehyde Cellulose-Silver Nanoparticle Composites through Ammoniated Nanocellulose Modification.

Given the widespread prevalence of viruses, there is an escalating demand for antimicrobial composites. Although the composite of dialdehyde cellulose and silver nanoparticles (DAC@Ag1) exhibits excellent antibacterial properties, its weak mechanical characteristics hinder its practical applicability. To address this limitation, cellulose nanofibers (CNFs) were initially ammoniated to yield N-CNF, which was subsequently incorporated into DAC@Ag1 as an enhancer, forming DAC@Ag1/N-CNF. We systematically investigated the optimal amount of N-CNF and characterized the DAC@Ag1/N-CNF using FT-IR, XPS, and XRD analyses to evaluate its additional properties. Notably, the optimal mass ratio of N-CNF to DAC@Ag1 was found to be 5:5, resulting in a substantial enhancement in mechanical properties, with a 139.8% increase in tensile elongation and a 33.1% increase in strength, reaching 10% and 125.24 MPa, respectively, compared to DAC@Ag1 alone. Furthermore, the inhibition zones against Escherichia coli and Staphylococcus aureus were significantly expanded to 7.9 mm and 15.9 mm, respectively, surpassing those of DAC@Ag1 alone by 154.8% and 467.9%, indicating remarkable improvements in antimicrobial efficacy. Mechanism analysis highlighted synergistic effects from chemical covalent bonding and hydrogen bonding in the DAC@Ag1/N-CNF, enhancing the mechanical and antimicrobial properties significantly. The addition of N-CNF markedly augmented the properties of the composite film, thereby facilitating its broader application in the antimicrobial field.

Largely Enhanced Thermoelectric Performance of Flexible Ag2Se Film by Cationic Doping and Dual-Phase Engineering.

Recent studies have shown that silver selenide is a promising thermoelectric material at room temperature. Herein, flexible films with a nominal composition of (Ag1-xCux)2Se are prepared by a simple and efficient one-pot method combined with vacuum-assisted filtration and hot pressing. The thermoelectric properties of the films are regulated by both cationic doping and a dual-phase strategy via a wet chemical method. As the x increases, not only Cu is doped into the Ag2Se, but different new phases (CuAgSe and/or CuSe2) also appear. The (Ag1-xCux)2Se film with x = 0.02 composed of Cu-doped Ag2Se and CuAgSe shows a high PF of ∼2540 µW m-1 K-2 (ZT ∼ 0.90) and outstanding flexibility at room temperature. The high thermoelectric properties of the film are due to the effect of Cu doping and the CuAgSe phase, including the increase in electrical conductivity caused by doping, the enhanced phonon scattering at the Ag2Se/CuAgSe interface, and the interaction between the energy filtering effect and the doping effect. In addition to the high output performance (PDmax = 28.08 W m-2, ΔT = 32.2 K), the flexible device assembled with the (Ag0.98Cu0.02)2Se film also has potential applications as a temperature sensor.

Characterization and Antioxidant and Antibacterial Activities of Carboxymethylated Tamarind Seed Polysaccharide Composite Films Incorporated with ε-Polylysine and Their Application in Fresh-Cut Green Bell Pepper Preservation.

Traditional petroleum-based food-packaging materials have poor permeability, limited active packaging properties, and difficulty in biodegradation, limiting their application. We developed a carboxymethylated tamarind seed polysaccharide composite film incorporated with ε-polylysine (CTPε) for better application in fresh-cut agricultural products. The CTPε films exhibit excellent water vapor barrier properties, but the mechanical properties are slightly reduced. Fourier transform infrared spectroscopy and X-ray diffraction spectra indicate the formation of hydrogen bonds between ε-PL and CTP, leading to their internal reorganization and dense network structure. With the increase of ε-PL concentration, composite films showed notable inhibition of postharvest pathogenic fungi and bacteria, a significant enhancement of 2,2'- azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical-scavenging activity, and gradual improvement of wettability performance. Cytotoxicity experiments confirmed the favorable biocompatibility when ε-PL was added at 0.3% (CTPε2). In fresh-cut bell pepper preservation experiments, the CTPε2 coating effectively delayed weight loss and malondialdehyde increase preserved the hardness, color, and nutrients of fresh-cut peppers and prolonged the shelf life of the fresh-cut peppers, as compared with the control group. Therefore, CTPε composite films are expected to be a valuable packaging material for extending the shelf life of freshly cut agricultural products.