High Barrier Research Articles

Cinnamaldehyde- and nonanal-incorporated polyvinyl alcohol/colloidal silicon dioxide films with synergistic antifungal activities

Biodegradable materials may help solve the problem of environmental pollution caused by conventional synthetic food packaging. Here, various amounts of colloidal silicon dioxide [CSD, 5, 10, and 15 wt% based on polyvinyl alcohol (PVA)] and 1 % SCAN, a 1:1 (v:v) combination of cinnamaldehyde and nonanal, were added to fabricate PVA-based films. Microstructure analyses using atomic force and scanning electron microscopes revealed that the films had uniform CSD dispersion, and the surface roughness rose along with the CSD concentration. The addition of SCAN prevented UV light transmission. In addition, the introduction of CSD enhanced the water-resistance abilities and tensile strengths of the composite films. The PVA/SCAN films exerted remarkable antifungal activities against Aspergillus flavus owing to a synergistic effect between cinnamaldehyde and nonanal. Furthermore, the PVA/SCAN/CSD film, contrasted with the PVA film containing SCAN alone, attenuated the SCAN loss during storage and also continually released SCAN from the film. In peanut preservation, the PVA/SCAN/CSD composite film was superior to the single-element films in antifungal activity, showing decreases of 76.66 % and 85.33 % in the production of conidia and aflatoxin B1, respectively. In conclusion, the PVA/SCAN/CSD composite film with high UV barrier, water-resistance ability, excellent mechanical properties and antifungal activity possesses a promising application potential in food packaging.

Light‐Induced Direct Decarboxylative Functionalization of Aromatic Carboxylic Acids

Aryl radicals are important intermediates in organic synthesis. The generation of these reactive species via direct decarboxylation of inexpensive and readily available aromatic carboxylic acids is an attractive goal. However, such a process intrinsically exhibits high energy barriers to overcome, which in consequence usually require precious metal catalysis, stoichiometric oxidants and harsh conditions, suffering from limitations such as poor functional group tolerance and low atom economy. In recent years, visible‐light‐induced photochemical reactions have provided new approaches to address this challenge. Three major strategies have been introduced in this emerging field: 1) one‐pot in‐situ activation of benzoic acids to generate intermediates such as benzoyl hypobromites or hypoiodites; 2) the use of specialized photocatalysts like biphenyl/1,4‐dicyanobenzene to promote decarboxylation through photo‐induced electron transfer or charge transfer processes; 3) photo‐induced LMCT (Ligand‐to‐Metal Charge Transfer) strategy where copper or iron salts coordinate to the carboxylate anion and generate aromatic radicals upon visible light excitation. On the basis of these three strategies, this review will systematically summarize the development of visible‐light‐induced direct decarboxylative functionalization of aromatic carboxylic acids, focusing on the reaction mechanism and substrate scope, and discuss their prospects in organic synthesis.

Strongly Coupled NiMo@Alloy‐LDH Interfaces with Low‐Barrier Schottky Junctions for Oxygen Evolution Reaction

AbstractThe main challenge in developing Schottky‐contact OER catalytic devices based on layered double hydroxides (LDHs) is to achieve metal–semiconductor junctions with low contact resistance and high charge transfer capacity. However, due to the presence of high potential barriers and Fermi pinning, conventional Schottky contacts are usually unsatisfactory, resulting in poor‐working electrode performance and high energy consumption. In this study, a new concept of “hindrance factor” is introduced to quantify the difficulty of electron transfer, and a low‐hindrance factor Schottky contact formed by strong coupling of semiconductor LDH and NiMo alloy clusters is designed. This interface guides charge redistribution, optimizes the bonding and orbital states of adsorption sites, and enhances the targeted adsorption of OH intermediates. The results show that the configured NiMo@NiFeCe‐LDH working electrode only needs 1.445 V (vs RHE) to drive the reaction and shows excellent durability in 400 h of testing. At the same time, based on this study, a strategy for screening high‐performance Schottky junctions is developed. This strategy provides a bridge for studying interface properties, orbital hybridization, and charge transfer, reveals the potential mechanism for reducing contact resistance, and has important guiding significance for screening high‐performance metal–semiconductor electrocatalysts and stability.

A density functional theory study of the formation of COS from CO and H2S on cesium sulfide

Alkali metals can promote the performance of MoS2 in methanethiol (CH3SH) synthesis from CO/H2/H2S mixtures. Recently, it has been found that alkali sulfides and most prominently Cs2S can also catalyze the reaction between CO and H2S to COS and H2, COS acting as an intermediate in CH3SH formation (M. Yu et al. J. Catal. 2022, 405, 116–128). Here, we study the nature of the active sites and the mechanism of the CO + H2S → COS + H2 reaction for the 6 low-index Miller planes of Cs2S. While CO adsorbs weakly, strong dissociative adsorption of H2S results in HS* and H* intermediates, which further stabilize the (001) facet as the dominant surface termination. The main reaction pathway towards COS involves the association of CO* and SH* to COSH* followed by its dehydrogenation in a Langmuir-Hinshelwood mechanism. Reactions of CO* with lattice S atoms have prohibitively high barriers due to the strong Cs-S bonds in Cs2S. Overall, the reaction rate is dominated by the (001) facet with small contributions of the (010), (011) and (101) surfaces. COSH* formation, its dehydrogenation to COS, and COS desorption compete as rate-controlling steps on these surfaces.

Properties of V-defect injectors in long wavelength GaN LEDs studied by near-field electro- and photoluminescence

The efficiency of multiple quantum well (QW) light emitting diodes (LEDs) to a large degree depends on uniformity of hole distribution between the QWs. Typically, transport between the QWs takes place via carrier capture into and thermionic emission out of the QWs. In InGaN/GaN QWs, the thermionic hole transport is hindered by the high quantum confinement and polarization barriers. To overcome this drawback, hole injection through semipolar QWs located at sidewalls of V-defects had been proposed. However, in the case of the V-defect injection, strong lateral emission variations take place. In this work, we explore the nature of these variations and the impact of the V-defects on the emission spectra and carrier dynamics. The study was performed by mapping electroluminescence (EL) and photoluminescence (PL) with a scanning near-field optical microscope in LEDs that contain a deeper well that can only be populated by holes through the V-defects. Applying different excitation schemes (electrical injection and optical excitation in the far- and near-field), we have shown that the EL intensity variations are caused by the lateral nonuniformity of the hole injection. We have also found that, in biased structures, the PL intensity and decay time in the V-defect regions are only moderately lower that in the V-defect-free regions thus showing no evidence of an efficient Shockley-–Read–Hall recombination. In the V-defect regions, the emission spectra experience a red shift and increased broadening, which suggests an increase of the In content and well width in the polar QWs close to the V-defects.

Knowledge Graph of Low-Carbon Technologies in the Energy Sector and Cost Evolution Based on LDA2Vec: A Case Study in China

Climate change has attracted global attention, highlighting the critical role of low-carbon technologies in addressing environmental challenges. Due to the multidisciplinary nature, complexity, and diversity of research content on low-carbon technologies, a comprehensive overview is still limited. This paper uses bibliometrics analysis to discuss the research status and hotspots of low-carbon technology from a macro-perspective. The LDA2Vec topic recognition model is adopted to identify key technical terms, and CiteSpace software 6.3.1 Advanced Edition is used to conduct in-depth analysis of the development trajectory of low-carbon technology. After checking the frequency of the relevant keywords, four key techniques were identified. In order to further analyze the research results, the learning curve theory is used to predict the cost development trend of key low-carbon technologies. The results show that: (i) low-carbon technologies play a key role in the energy sector and have a potential impact on policy making, and the cost of related technologies will be significantly reduced in the next few years. (ii) Global low-carbon technologies have entered an important period of development, but remaining challenges need to be addressed by optimizing technological performance. (iii) It is very important to strengthen the research on hydrogen production technology and photovoltaic power generation technology; the cost reduction in hydrogen production technology is still significant and there is room for further optimization. (iv) To effectively address the high costs and technical barriers associated with emerging low-carbon technologies, increased funding for research and development is critical.

Novel Insecticidal Pyridylhydrazono Derivatives Identified via Scaffold Hopping and Conformation Regulation Strategies.

Insect transient receptor potential vanilloid (TRPV) channels are critical targets for insecticides. In this study, various scaffold-hopping strategies were employed in the rational design of pyridylhydrazono derivatives as potential insect TRPV channels modulators. Insecticidal bioassay demonstrated that the initial target compounds exhibited lower insecticidal activity compared to pymetrozine, with the optimal compound B3 exhibiting a mortality rate of 53.3 % against Aphis craccivora at 400 mg L-1. Conformation analysis indicated that the high energy barrier required for the transition from the lowest-energy conformation to the active conformation may be a key factor contributing to the reduced insecticidal activities of the target compounds. Further structural optimizations aimed at reducing this energy barrier through binding mode-based conformation regulation led to the identification of optimal target 4-(3'-pyridylhydrazono)pyrazol-5-one derivatives C1 and C2. These compounds exhibited reduced transition energy barriers and improved insecticidal activity, with moderate mortality rate of 66.3 % and 75.7 % against A. craccivora at 400 mg L-1, respectively. These findings provide valuable insights for future research on the discovery of insect TRPV modulators and have significant implications for the development of more effective agricultural insecticides.

High sulfur content cathode composites utilizing the Li(CB9H10)0.7(CB11H12)0.3 superionic conductor for all−solid−state Li−S batteries

Rechargeable batteries are encountering ever−growing demands for further improvements in energy density and safety. All−solid−state lithium−sulfur (Li−S) batteries have the potential to meet these demands, because they employ not only high−energy−density electrodes but also non−flammable inorganic solid electrolytes. However, the sluggish conducting nature of the S cathode results in high electric transfer barriers, making high S content in solid−state cathode composites difficult. In this study, we report the fabrication and reaction behavior of high S content cathode composites using a Li(CB9H10)0.7(CB11H12)0.3 superionic conductor. The lithium superionic conduction, high deformability, and low material density of Li(CB9H10)0.7(CB11H12)0.3 solid electrolyte facilitate intimate and favorable connections with sulfur and carbon, leading to facile electrical migrations within sulfur−Li(CB9H10)0.7(CB11H12)0.3−carbon (S−CH−C) composites. In battery tests, these close interconnections enable the fabrication of S−CH−C cathode composites through simple physical hand−mixing, allowing for reversible discharge−charge cycling of all−solid−state Li−S batteries engaging high energy density (>1,000 Wh kg−1cathode composite) S−CH−C cathode composites with a high S content of 50 wt%. In addition, a comparative investigation using various carbonaceous conductive materials suggests that simultaneously achieving high surface area, nanoparticle size, and non−spherical rough morphology is crucial for developing high S content S−CH−C composites with superior battery performances.

Ohmic Contact Resistance in SiC Diodes with Ti and NiSi P<sup>+</sup> Contacts

Ohmic contacts play a major role in the signal transfer between the semiconductor device and the external circuitry. One of the main technological issues to develop high-performance SiC-based devices is the control of metal/SiC contact properties to fabricate low resistance and high stability SiC Ohmic contacts to p-type SiC. This is mostly due to intrinsic SiC characteristics like large work function, low dopant activation for p-type materials and low hole mobility. These limits are even more emphasized in SiC JBS or MPS diodes, where Schottky and Ohmic contacts on the P doped regions embedded in the active area to improve surge ruggedness are usually formed by using the same metallization process. This naturally results either in a high Schottky barrier height in the Schottky contact with consequent increase of the conduction loss at low currents or in a poorly conductive Ohmic contact, leading to reduced IFSM capability. Therefore, the optimization and control of the process parameters like for example the P+ doping concentration peak underneath the metallization layer and the annealing process temperatures is crucial to obtain a good Ohmic contact and enhance the device´s robustness against surge current.

Intraphase Switching of Hollow CoCuFe Nanocubes for Efficient Electrochemical Nitrite Reduction to Ammonia.

This study addresses the urgent need to focus on the nitrite reduction reaction (NO2-RR) to ammonia (NH3). A ternary-metal Prussian blue analogue (CoCuFe-PBA) was utilized as the template material, leveraging its tunable electronic properties to synthesize CoCuFe oxide (CoCuFe-O) through controlled calcination. Subsequently, a CoCuFe alloy (CoCuFe-A) was obtained via pulsed laser irradiation in liquids. The electrochemical properties of CoCuFe-O, derived from the PBA crystal structure, demonstrated a high yield of NH4+ at a rate of 555.84 μmol h-1 cm-2, with the highest Faradaic efficiency of 91.8% and a selectivity of 97.3% during a 1-h NO2-RR under an optimized potential of -1.0 V vs. Ag/AgCl. In situ Raman spectroscopy revealed the collaborative role of redox pairs (Co3+/Co2+ and Fe3+/Fe2+) as proton (H+) suppliers, with Cu centers serving as NO2- binders, thereby enhancing the reaction rate. Additionally, theoretical studies confirmed that Fe and Co atoms are more reactive than Cu toward intermediates playing crucial roles in hydrogenation, while Cu primarily activates NO owing to hydrogenation by the Fe and Co atoms and a high kinetic barrier in H2O* adsorption. This comprehensive investigation provides valuable insights into the electrochemical NO2-RR, establishing a foundation for efficient and sustainable NH3 synthesis strategies.

Quantum-tunneling deep neural network for optical illusion recognition

The discovery of the quantum tunneling (QT) effect—the transmission of particles through a high potential barrier—was one of the most impressive achievements of quantum mechanics made in the 1920s. Responding to the contemporary challenges, I introduce a deep neural network (DNN) architecture that processes information using the effect of QT. I demonstrate the ability of QT-DNN to recognize optical illusions like a human. Tasking QT-DNN to simulate human perception of the Necker cube and Rubin’s vase, I provide arguments in favor of the superiority of QT-based activation functions over the activation functions optimized for modern applications in machine vision, also showing that, at the fundamental level, QT-DNN is closely related to biology-inspired DNNs and models based on the principles of quantum information processing.

High Rotational Barrier Atropisomers.

Atropisomers have attracted a great deal of attention lately due to their numerous applications in organic synthesis and to their employment in drug discovery. However, the synthetic arsenal at our disposal with which to access them remains limited. The research described herein is two-pronged; we both demonstrate the use of MCR chemistry as a synthetic strategy for the de novo synthesis of a class of atropisomers having high barriers to rotation with the simultaneous insertion of multiple chiral elements and we study these unprecedented molecular systems by employing a combination of crystallography, NMR and DFT calculations. By fully exploiting the synthetic capabilities of our chemistry, we have been able to monitor a range of different types of interaction, i. e. π-π, CH-π, heteroatom-π and CD-π, in order to conduct structure-property studies. The results could be applied both to atroposelective synthesis and in drug discovery.

Confinement Effect in Multilayer Films Made from Semicrystalline and Bio-Based Polyamide and Polylactic Acid.

Bio-based multilayer films were prepared by using the innovative nanolayer coextrusion process to produce films with a number of alternating layers varying from 3 to 2049. For the first time, a semicrystalline polymer was confined by another semicrystalline polymer by nanolayering in order to develop high barrier polyamide (PA11)/polylactic acid (PLA) films without compromising thermal stability and mechanical behavior. This process allows the preparation of nanostratified films with thin layers (down to nanometric thicknesses) in which a confinement effect can be induced. The stratified structure has been investigated, and the layer thicknesses have been measured. Barrier properties were successfully correlated to the microstructure, as well as the thermal behavior, and mechanical properties. The layer continuity was fully achieved for most of the films, but some layer breakups have been observed on the film with the thinnest PLA layer (2049-layers film). Coextruding PLA with PA11 has induced an increase in PLA crystallinity (from 4 to 16%) along with an increase in thermal stability of the multilayer films without impacting PA11 properties. Gas barrier properties were driven by the PLA confined layers due to the microstructural rearrangement by increasing crystallinity, whereas water barrier properties were governed by the PA11 confining layers due to its lower water affinity. As a consequence, a decrease of water permeability (up to 11 times less permeable for the 6M film) but an increase of gas barrier properties (barrier improvement factor (BIF) of 66% for the 0M film for N2 and BIF of 36% for the 6M film for CO2 for instance) were evidenced as the layer number was increased. This study paves the way for the development of ecofriendly materials with outstanding barrier performances and highlights the importance of nonmiscible polymers adhesion at melt state and additives presence.

Hydrogen Spillover Mechanism at the Metal–Metal Interface in Electrocatalytic Hydrogenation

AbstractHydrogen spillover in metal‐supported catalysts can largely enhance electrocatalytic hydrogenation performance and reduce energy consumption. However, its fundamental mechanism, especially at the metal–metal interface, remains further explored, impeding relevant catalyst design. Here, we theoretically profile that a large free energy difference in hydrogen adsorption on two different metals (|ΔGH‐metal(i)−ΔGH‐metal(ii)|) induces a high kinetic barrier to hydrogen spillover between the metals. Minimizing the difference in their d‐band centers (Δϵd) should reduce |ΔGH‐metal(i)−ΔGH‐metal(ii)|, lowering the kinetic barrier to hydrogen spillover for improved electrocatalytic hydrogenation. We demonstrated this concept using copper‐supported ruthenium–platinum alloys with the smallest Δϵd, which delivered record high electrocatalytic nitrate hydrogenation performance, with ammonia production rate of 3.45±0.12 mmol h−1 cm−2 and Faraday efficiency of 99.8±0.2 %, at low energy consumption of 21.4 kWh kgamm−1. Using these catalysts, we further achieve continuous ammonia and formic acid production with a record high‐profit space.

Simulating Crystallization in a Colloidal System Using State Predictive Information Bottleneck Based Enhanced Sampling.

We investigate crystal nucleation in supersaturated colloid suspensions using enhanced molecular dynamics simulations augmented with machine learning techniques. The simulations reveal that crystallization in the model colloidal system studied here, with particles interacting through a repulsive screened Coulomb Yukawa potential, proceeds from vapor to dense liquid droplet to crystalline phases across multiple high barriers. Employing a one-dimensional reaction coordinate derived from the State Predictive Information Bottleneck framework, our simulations capture back-and-forth phase transitions across multiple barriers effectively in biased metadynamics simulations. We obtain relative free energy differences between different phases and also quantify the roles of different molecular level features in driving the phase changes.

Modulation of electron transfer behavior on Fe2P-Co2P/NPC oxygen electrocatalyst by lattice cation substitution engineering and charge transport network design for rechargeable Zn-air batteries

Crystal structure modulation engineering on the lattice scale and charge transport network design on the micro/nano scale work together to endow oxygen electrocatalysts with high reactivity to fully release the capacity of Zn-air batteries (ZABs) as the next-generation green energy storage devices. Metal phosphide-based oxygen reduction reaction (ORR)/oxygen evolution reaction (OER) electrocatalysts with tunable electronic structures, variable valence states, and moderate overpotentials are recognized as the most promising and ideal candidates for air cathodes. The cation substitution strategy overcomes the drawback that single metal phosphides with fewer active sites and high adsorption barriers are not sufficient to achieve satisfactory electrocatalytic performance. In this paper, the Fe2P-Co2P/NPC oxygen electrocatalyst employing lattice cation site substitution engineering and three-dimensional (3D) conductive network encapsulation strategies are constructed to successfully ensure fast electron transfer behavior and safe charge/discharge energy storage. Noteworthy, the presence of Schottky barriers at the interface of the two materials hinders the electron reflux, which promotes a unidirectional flow of electrons, and increases the electron condensation in the OER and ORR processes. Relying on these features, the Fe2P-Co2P/NPC-assembled liquid ZABs achieved power densities, specific capacities, and energy densities of 175.18 mW cm-2, 805.75 mAh gZn-1, and 958.84 Wh kg-1, respectively, and importantly good rate performances and stability were exhibited even under high-current-density operation. The corresponding flexible solid-state ZABs also possesses superior electrochemical activity and mechanical flexibility. This work paves the way for the construction of bifunctional oxygen electrocatalysts with high-speed electron transfer channels, thus advancing the development of wearable electronic devices.

Modulating Magnetic Performance in DyIII Single Ion Magnets With N5O2 Ligands

ABSTRACT[Dy (LMe)(H2O)]CF3SO3·0.25H2O (1·0.25H2O), where H2LMe is the reported ligand 2,2′‐(((pyridine‐2,6‐diylbis (methylene))bis((pyridin‐2‐ylmethyl)azanediyl))bis (methylene))bis(4‐methylphenol), shows the DyIII ion in an N5O3 environment, with triangular dodecahedral geometry (D2d symmetry). 1·0.25H2O is a single ion magnet (SIM) with an energy barrier for spin reversal of 510 K, and open hysteresis loops up to 8 K. The magnetostructural comparison of 1·0.25H2O with some closely related complexes and with other eight‐coordinated SIMs with high energy barriers (> 300 K) allows to draw some conclusions to enhance the magnetic performance in these nanomagnets with non‐purely axial geometries. Ab initio calculations complement and support the experimental results.

Surface chlorination of IrO2(110) by HCl.

The ability to controllably chlorinate metal-oxide surfaces can provide opportunities for designing selective oxidation catalysts. In the present study, we investigated the surface chlorination of IrO2(110) by HCl using temperature programmed reaction spectroscopy (TPRS), x-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) calculations. We find that exposing IrO2(110) to HCl, followed by heating to 650K in ultrahigh vacuum, produces nearly equal quantities of on-top and bridging Cl atoms on the surface, Clt and Clbr, where the Clbr atoms replace O-atoms that are removed from the surface by H2O formation. After HCl adsorption at 85K, only H2O desorbs at low Cl coverages during TPRS, but HCl begins to desorb in increasing yields as the Cl coverage is increased above about 0.5 monolayer (ML). The desorption of Cl2 was not observed under any conditions, in good agreement with the high barrier for this reaction predicted by DFT. A maximum Cl coverage of 1 ML, with nearly equal coverages of Clt and Clbr atoms, could be generated by reacting HCl with IrO2(110) in UHV. Our results suggest that a kinetic competition between recombinative HCl and H2O desorption under the conditions studied limits the saturation Cl coverage to a value less than the 2 ML maximum predicted by thermodynamics. XPS further shows that the partitioning of Cl between the Clt and Clbr states can be altered by subjecting partially chlorinated IrO2(110) to reductive or oxidative treatments, demonstrating that the Cl site population can change dynamically in response to the gas environment. Our results provide insights for understanding the chlorination of IrO2(110) by HCl and can enable future experimental studies to determine how Cl-modification alters the surface chemical reactivity of IrO2(110) and potentially enhances selectivity toward partial oxidation chemistry.

P–d Orbitals Coupling Heterosites of Ni2P/NiFe‐LDH Interface Enable O─H Cleavage for Water Splitting

AbstractElectrocatalytic water splitting for hydrogen production still faces a bottleneck due to sluggish reactive kinetics and high reactive energy barriers. Herein, p–d orbital coupling P–Fe heterosites are constructed at Ni2P–FeNi‐LDH interfaces to enhance the O─H bond cleavage of reaction intermediates H2O* and OH* for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), respectively. The Ni2P/NiFe‐LDH heterostructure shows superior HER and OER activities for alkaline water splitting with overpotentials of 230 and 270 mV at 100 mA cm−2, respectively, and even exhibits high activity for electrocatalytic alkaline seawater splitting. The interaction of P 2p and Fe 3d orbitals at Ni2P–FeNi‐LDH interfaces upshifts the d‐band center of Fe and downshifts the p‐band center of P. This finding not only facilitates the dissociation of O─H bonds in H2O and promotes the Volmer–Heyrovsky step for HER, but also reduces the energy barrier for the rate‐determining step of OER from OH* to O* transition. This work proposes a new approach to constructing p–d heterosites at heterojunctions to facilitate reactive kinetics and reduce the energy barrier for electrocatalysis.

Sodium alginate-based indicator film with enhanced physicochemical properties induced by cellulose nanocrystals and monitor the freshness of chilled meat

Intelligent indicator films with colorimetric pH indicator properties were developed, incorporating black soybean seed coat anthocyanin (BA), cellulose nanocrystals (CNC), and sodium alginate (SA) to monitor meat freshness. The effect of different CNC additions on the microstructure, water barrier properties of the films, and BA release kinetics were comprehensively investigated. The results showed that with the increasement of CNC addition, the mechanical properties of SA/BA/CNC films were improved, the water contact angle significantly increased from 51.6° to 69°. Moreover, water solubility, vapor adsorption, and permeability significantly decreased, indicating enhanced water barrier properties. The release kinetic results showed that BA was released rapidly within 72 h and slowly thereafter, and its release process was described by Fick's model. Films with 7 % and 10 % CNC had lower BA diffusion coefficients. Their diffusions were formulated as linear regression equations (y = nx + a), where R2 was >0.80 and n was <0.50. Structural characterization showed that CNC immobilized BA mainly through hydrogen bonding, forming compact network microstructures with SA and BA. Meat freshness monitoring results showed that the film containing 7 % CNC showed visible color changes with increasing total volatile basic nitrogen and pH, along with low BA release, high water barrier and mechanical properties. Therefore, CNC has great potential for improving the physicochemical properties of indicator films, and the intelligent colorimetric indicator film could be applied to various food product.