Nanocellulose Research Articles

Novel composite film based on cassava starch and poly (diallyldimethylammonium chloride) reinforced with nanocrystalline cellulose for bacteria and coronavirus inactivation

Novel composite film based on cassava starch and poly (diallyldimethylammonium chloride) reinforced with nanocrystalline cellulose for bacteria and coronavirus inactivation

Pickering emulsion stabilized by cellulose nanofibril from pineapple leaves for biofoam manufacture

Cellulose nano fibril (CNF) can be selected as an agent of pickering emulsion in biofoam manufacture. This study thoroughly investigates the pickering emulsion method for producing biofoam, the characterization of CNF from pineapple leaves, the production of biofoam with various concentration of CNF and surfactant, and the effect of these parameters on the properties of wet foam and dry foam. CNF was created by mechanical grinding then the stability and morphology were evaluated. The pickering emulsion mechanism in biofoam manufacture was investigated using foamability and foam stability with various CNF and surfactant concentration. As the results, CNF concentrations will create varying zeta potential values. The morphology of CNF shows that it has a structure-like entangled network. The stability test demonstrates that adding CNF improves the stability and foamability of biofoam by the pickering effect. Biofoam without CNF has an unstable structure and is easily collapse when dried in an oven. The concentration of CNF and the amount of surfactant utilized altered the qualities of both wet and dry foam. The lower concentration of CNF and the addition of surfactant could increases foamability, high porosity, water absorption, and biodegradability; as well as low density, contact angle and bending characteristics. In biofoam that consists of 2 % CNF, the stability of wet foam increases as the amount of surfactant added, resulting in a biofoam with low tensile strength.

Magnetically processed composite material for the production of plywood based on compacted aspen veneer (Populus tremula L.) and a complex binder with nanocrystalline cellulose

Magnetically processed composite material for the production of plywood based on compacted aspen veneer (Populus tremula L.) and a complex binder with nanocrystalline cellulose

Simultaneous removal of Ni2+ and Congo red from wastewater by crystalline nanocellulose - Modified coal bionanocomposites: Continuous adsorption study with mathematical modeling

Due to ultra-fast technological improvement and rapid urbanization nowadays, industries have generated a huge amount of wastewater that is discharged directly into the environment. Resulting in harsh damage to ecology and public safety/security by contaminating the ground/surface water sources. Therefore, it is very crucial to purify this wastewater before discharging/reusing. This study will be devoted to the latest enhancements along with the new route of production of the multifunctional Crystalline Nanocellulose-Modified Bituminous Coal (CNC-MC) bionanocomposites. Besides these, the significant implementation of the fabricated CNC-MC bionanosorbents for the simultaneous removal of Ni2+ and Congo red (CR) from bulk-scale industrial wastewater has been stated. Conversely, influential parameters like inlet concentration (25–45 ppm), flow rate (3–5 mL/min), and adsorbent bed height (0.2–0.8 cm) were explored. The bionanosorbents were characterized by using some state-of-the-art equipment such as FTIR-ATR, XRD, BET, FESEM, and TGA analysis, while the water samples were analyzed by AAS and UV-NIR techniques. Results suggested that the fabricated CNC-MC bionanocomposites possessed a considerable amount of active binding sites/functional groups, showed high thermal stability up to 700°C, and had a high crystallinity index (around 92.41 ± 0.009%). They revealed a noteworthy honeycomb-like mesoporous microstructure with a significant specific surface area. Due to these outstanding features, this multifunctional bionanosorbents has exhibited sensational adsorption performance. Meanwhile, the maximum removal efficiency and percentage were observed at approximately 328.7 and 478.3 mg/g, as well as around 67.95 and 76.65% for Ni2+ and CR. The experimental data was evaluated by three well-known column models, namely the Thomas, Adam-Bohart, and Yoon-Nelson models, and respectable agreement was found. That is similarly appropriate for the justification of the experimental breakthrough curve by supporting the Langmuir isotherm and 2nd-order reversible reaction kinetics. Hence, this novel CNC-MC bionanosorbent could be beneficially used to purify industrial wastewater in an economical and eco-friendly way for sustainable environmental safety.

Folic acid-modified nanocrystalline cellulose for enhanced delivery and anti-cancer effects of crocin

Crocin is a carotenoid compound in saffron with anti-cancer properties. However, its therapeutic application is limited by its low absorption, bioavailability, and stability, which can be overcome through nanocarrier delivery systems. This study used surface-modified Nano-crystalline cellulose (NCC) to deliver crocin to cancer cells. NCC modified with CTAB were loaded with crocin and then conjugated with folic acid (NCF-CR-NPs). The synthesized nanoparticles (NPs) were characterized using FTIR, XRD, DLS, and FESEM. The crystallinity index of NCC was 66.64%, higher than microcrystalline cellulose (61.4%). The crocin loading and encapsulation efficiency in NCF-CR-NPs were evaluated. Toxicity testing by MTT assay showed that NCF-CR-NPs had higher toxicity against various cancer cell lines, including colon cancer HT-29 cells (IC50 ~ 11.6 μg/ml), compared to free crocin. Fluorescent staining, flow cytometry, and molecular analysis confirmed that NCF-CR-NPs induced apoptosis in HT-29 cells by increasing p53 and caspase 8 expression. The antioxidant capacity of NCF-CR-NPs was also evaluated using ABTS and DPPH radical scavenging assays. NCF-CR-NPs exhibited high free radical scavenging ability, with an IC50 of ~ 46.5 μg/ml for ABTS. In conclusion, this study demonstrates the potential of NCF-CR-NPs to deliver crocin to cancer cells effectively. The NPs exhibited enhanced anti-cancer and antioxidant activities compared to free crocin, making them a promising nanocarrier system for crocin-based cancer therapy.

Synthesis of cellulose nano fiber from palmyrah fruit fiber and its applicability as a reinforcement agent on starch based biodegradable film

The global trend in packaging is shifting towards environmentally friendly, natural materials that decompose easily. Among the bio-based packaging materials, starch is a renewable, biodegradable, bio-compatible, and easily accessible source. However, starch-based biodegradable films depict weak mechanical properties compared with synthetic polymers. This problem can be solved by incorporating reinforcement fillers into the starch matrix. Palmyrah fruit (Borassus flabellifer L.) waste can be a good source to obtain fillers due to its high cellulose content. The aim of the study was to investigate the reinforcement of starch-based biodegradable films with the incorporation of pure cellulose nanofiber (CNF) obtained from palmyrah fruit fiber (PFF). Chemical treatments such as alkaline treatment (4% NaOH), bleaching [1% Ca(OCl)2], and acid hydrolysis (10 moldm-3 H2SO4) were done successively to obtain pure CNF from PFF. CNF was characterized using FTIR and particle size distribution (PSD) was analyzed by granulometry. The yield of CNF from PFF was 37.890±0.008 %. The results of FTIR depicted CNF was synthesized successfully. Five different biodegradable films were prepared by varying the amount of palmyrah tuber starch (4.5-2.5 w/w %) and CNF (0.0-2.0 w/w %) while the amount of glycerin (1.5 w/w %) and gelatin (1 w/w %) were kept constant. PSD results revealed that nano-sized CNF (10-100 nm) was synthesized successfully. The optimized film was selected based on the tensile strength and low water vapor transmission rate. Optimized film formulation, with palmyra tuber starch (3 w/w %) and CNF (1.5 w/w %) showed desirable physical, mechanical and optical properties, including the thickness, moisture content, water vapor transmission rate, water uptake, transparency at 600 nm, water activity, water solubility and tensile strength of 0.192±0.004 mm, 11.07±0.04 %, 3.870±0.005 g/m2.day, 22.34±0.05 %, 3.97±0.01 %, 0.440±0.001, 51.68±0.140 % and 9.55 MPa respectively. All films showed excellent soil biodegradability within two weeks. In conclusion, palmyra fruit CNF can be effectively used to reinforce starch-based biodegradable packaging films.

Enhanced Total Contactless Photothermal Desalination by Translucent Thin Film Coating of Crystalline Nanocellulose.

The innovative approach of harnessing abundant solar energy to facilitate water purification holds great potential for addressing a diverse range of water-related challenges. Utilizing the same method of photothermal desalination is highly promising, sustainable, and cost effective. However, in photothermal desalination, generally, steam is generated at the liquid-air interface. Despite its immense potential, this results in a lower evaporation rate and is prone to salt fouling. Therefore, to address two main challenges, (1) fouling and (2) maximum interfacial temperature (100 °C), here, we report total contactless photothermal desalination by a translucent thin film coating of Crystalline Nanocellulose (CNC). In contactless photothermal desalination, the active photothermal layer remains in no physical contact with the saline water; thus, automatic antifouling and a temperature above the boiling point of water can be achieved for water purification. In this report, we have sustainably extracted CNC from waste sawdust by a sonochemical extraction method using minimal chemicals. Additionally, the sonoextraction method through cavitation helps in the desulfation of CNC. These thermally stable and highly crystalline CNCs are used in making active translucent photothermal active layers for photothermal desalination. CNCs were well characterized by both microscopic and spectroscopic techniques. In the photothermal desalination, the results show an augmented evaporation rate of ∼3.30 kg/m2·h and virtually infinite recyclability for longer usability. Moreover, the integrated setup reported here comprises an independent module with a highly flexible design that mimics the greenhouse effect for a high solar-to-steam output.

Functionalized nano cellulose double-template imprinted aerogel microsphere for the targeted enrichment of taxanes

Paclitaxel, a diterpenoid isolated from the bark of Taxus wallichiana var. chinensis (Pilger) Florin, is currently showing significant therapeutic effects against a variety of cancers. Baccatin III (Bac) and 10-Deacetylbaccatin III (10-DAB) are in great demand as important precursors for the synthesis of paclitaxel. This work aims to develop a simple, rapid and highly selective, safe, and non-polluting molecularly imprinted material for 10-DAB and Bac enrichment. In this study, we innovatively prepared molecularly imprinted materials with nanocellulose aerogel microspheres and 2-vinylpyridine (2-VP) as a bifunctional monomer, and 10-DAB and Bac as bis-template molecules. In particular, functionalized nanocellulose dual-template molecularly imprinted aerogel microsphere (FNCAG-DMIM) were successfully synthesized by the bifunctional introduction of functional nanocellulose aerogel microsphere (FNCAG) modified with Polyethyleneimine (PEI) as a carrier and functional monomer, which provided a large number of recognition sites for bimodal molecules. FNCAG-DMIM showed high specificity for 10-DAB and Bac specific assays. Under the optimal experimental conditions, the adsorption capacities of FNCAG-DMIM for 10-DAB and Bac reached 52.27 mg g−1 and 53.81 mg g−1, respectively. In addition, it showed good reliability and practicality in the determination of real samples. The present study extends the research on the synthesis of natural functional monomers by molecularly imprinted materials and opens up new horizons for the targeted isolation of plant compounds by dual-template molecularly imprinted materials.

Advanced Polymer Materials for Protecting Lithium Metal Anodes of Liquid‐State and Solid‐State Lithium Batteries

AbstractLithium metal batteries (LMBs) are considered as one type of the most promising next‐generation energy storage devices with high‐energy‐density, and stabilizing the lithium metal anodes (LMAs) to overcome LMBs’ safety concerns and performance degradation has attracted extensive attention. Introducing advanced polymer materials into the critical components of LMBs has proven to be an effective and promising approach for stabilizing LMAs toward practical application of LMBs. In addressing the lack of a timely review on the emerging progress of advanced polymer materials in LMBs for stabilizing LMAs, a comprehensive article summarizing the most recent developments of multiscale cellulose materials, including micron cellulose (MC) and nanocellulose (NC), in LMBs is reviewed. First, the basic structures of cellulose, characteristics comparison, and the development history of introducing cellulose into LMBs are presented. Furthermore, the roles of multiscale cellulose materials and functional mechanisms in various components of LMBs for stabilizing LMAs are summarized. A general conclusion and a perspective on the current limitations and future research directions of cellulose‐based stable LMBs are proposed. The aim of this review is not only to summarize the recent progress of multiscale cellulose materials in stabilizing LMAs but also to lighten the pathways for realizing LMBs’ practical application.

Nanocellulose extraction from acai bagasse through mixed acid hydrolysis and oxidative techniques

Exploring new biomass sources for nanocellulose (NC) extraction is crucial in elevating the economic value of readily available renewable resources. This study compares NC extracted from acai (Euterpe oleracea) bagasse using different methods: mixed acid hydrolysis, 2,2,6,6-tetramethylpiperidinyl-1-oxy (TEMPO) mediation, and ammonium persulfate (APS) oxidations. A comprehensive analysis investigates the impact of each treatment on the physical-chemical properties of the nanoparticles, including chemical structure, crystallinity, morphology, and thermal and suspension stability. NCs obtained through mixed acid hydrolysis exhibit the highest crystallinity (62 %) and low sulfate groups on their surfaces. Consequently, they demonstrate excellent thermal stability but poor colloidal stability in water. Oxidized NCs undergo chemical modification, converting alcoholic groups into carboxyl, resulting in NCs with zeta potentials ranging between −25.30 ± 0.81 and − 27.49 ± 1.07 mV. APS oxidation produces nanoparticles with superior thermal stability compared to TEMPO oxidation. Atomic Force Microscopy (AFM) images reveal that all nanocelluloses share characteristics of nanofibers (CNFs). This comprehensive characterization highlights the potential of acai bagasse for yielding high-added-value bioproducts suitable for versatile applications.

Recent progress in polyvinyl alcohol (PVA)/nanocellulose composite films for packaging applications: A comprehensive review of the impact on physico‐mechanical properties

AbstractAs society advances, the demand for innovative and sustainable food processing techniques and materials has grown significantly. The food industry, especially the food packaging sector, faces the challenge of developing cost‐effective and sustainable packaging materials to meet consumers' increasing demands. One promising solution for this is the use of biodegradable polymers such as polyvinyl alcohol (PVA), but standalone PVA cannot meet the required properties of packaging materials. The use of nanocellulose (NC) as fillers has been intensively studied recently. This review article provides a comprehensive overview of existing studies focusing on the preparation of PVA/NC composite films for packaging applications. The effects of NC loading on the physico‐mechanical properties of these films, including tensile strength, elongation, water absorption/swelling behavior, barrier properties, and optical properties, have been thoroughly examined. Overall, the general findings suggest that the reinforcement of NC in the PVA polymer matrix leads to improvements in the films' properties. Specifically, the addition of NC enhances tensile strength, reduces O2, CO2, and water vapor transmission rates, and decreases the films' propensity to absorb moisture or swell under wet conditions. However, it is important to note that the presence of NC compromises the optical properties of the films by reducing transparency, and the NC content beyond threshold level reduces the feasibility of the composite film. By synthesizing these findings, this review underscores the potential of PVA/NC composite films as promising materials for packaging applications. Moving forward, further research efforts are warranted to optimize the formulation and processing of these composite films to strike a balance between mechanical strength and optical clarity, thus advancing their practical utility in the packaging industry.

Novel DES- ultrasonication assisted process for nanocellulose synthesis using Box Behnken design

This study aimed to synthesize nanocellulose (NC) from sugarcane bagasse (SCB) and pineapple crown leaves (PCLs) with the use of the DES-ultrasonication technique. The Box Behenken design (BBD) was used as a design of experiment to explain the effects of parameters on the NC yield. The independent variables varied in this study were reaction temperature (80, 95, 110 °C), time (2, 4, and 6 h), and DES 2 ratio (1:1, 2:1, 3:1). A high yield of NCs was obtained from SCB and PCLs through a DES- ultrasonication process. The maximum yield of 76.91 % was obtained at the reaction temperature, reaction time, and DES ratio of 95 °C, 4 h, and 2:1 respectively for SCB-derived NC. In the case of PCLs, the maximum yield of NC of 69 % resulted from the reaction temperature, reaction time, and DES ratio of 80 °C, 4 h, and 3:1. The yield for both raw materials differed due to the structural variations. NCs obtained from SCB and PCLs exhibited a higher crystallinity index of about 58.10 and 62.07 %, slightly higher than reported studies. SEM images showed the rod-like structures of synthesized NCs. The thermal stability of both the synthesized NCs increased compared to raw materials. Hence, due to their high thermal stability and crystallinity, the synthesized NCs can be suitable for reinforcement polymer composite applications.

Biowaste Valorization of Palm Tree Phoenix dactylifera L. for Nanocellulose Production.

The desire to reduce reliance on oil resources arises from the concerns about carbon footprint and nonrenewability. Conversely, the global presence of over 100 million palm trees poses a significant challenge due to the substantial amount of biowaste generated annually. Additionally, the use of nanocellulose (NC) as a cost-effective material is steadily gaining recognition for its growing adaptability over time. The main goal of this study is to biosynthesized NC from Iraqi date palm Phoenix dactylifera leaves waste with low-concentration acid-alkali treatment. The date palm leaves waste yields 20 g of NC from 100 g of leaves before acid hydrolysis treatment. The chemical components of biosynthesized NC were 47.90%, 26.78%, and 24.67% for α-cellulose, hemicellulose, and lignin, respectively. In order to study their properties, NC from raw date palm leaves was studied by microscopic techniques such as scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, and atomic force microscope (AFM). SEM results revealed rod-like structured NC as well as combined long-fine fibrous structures rather than compacted bundles with sizes ranging between 31 and 74 nm. With EDX, all spectra exhibit the peaks of carbon and oxygen as the main elements with 63.8% and 10.44%, respectively, in their compositions, which relate to the typical composition of cellulose. The 3D image of AFM NC with a tapping mode presented a highly uniform distribution of NC with a size of ∼15 nm. The statistical roughness analysis shows that the obtained roughness average is 7.20 nm with the root-mean-square roughness value of 21.56 nm, which corresponded relatively with the micrographs of SEM. The results of this study demonstrate the promise of using date palm waste as raw material to produce NC as green nanocomposite from biodegradable nanomaterials for water purification and sustained drug delivery for biomedical applications. In this regard and because of the insufficient reports about the extraction of NC from palm tree leaves waste, the objective of this study was designed to fabricate NC biologically from fibers sourced from the waste of Iraqi date palm P. dactylifera leaves that left in agricultural lands or burned, which can be an ecological and health problem as a bionanocomposites in the medical and industrial field and as alternative resources of wood materials.

Enhancing biodegradable polymer surface wettability properties through atmospheric plasma treatmsurfaent and nanocellulose incorporation

This study investigates the effects of atmospheric plasma treatment on the surface properties of polylactic acid (PLA)/nanocrystalline cellulose (CNC) composites, aiming to improve their wettability and mechanical properties. The research utilizes a twin-screw extrusion process for fabricating PLA/CNC biocomposites, followed by surface modification using a custom-built, with a tenfold high-voltage atmospheric plasma system. The motivation of this treatment was to improved surface wettability and potential for enhanced adhesive bonding in ecological applications. These findings contribute to developing more sustainable composite materials by providing a method to improve the functionality of biodegradable polymers without compromising their environmental benefits.

Physicochemical Properties of Cellulose Nanocrystals Extracted from Postconsumer Polyester/Cotton-Blended Fabrics and Their Effects on PVA Composite Films.

The utilisation of cotton waste as precursors in the synthesis of nanocrystalline cellulose has gained significant attention. This approach suggests a sustainable solution to address the growing concern of textile waste accumulation while simultaneously producing a valuable material. The main aim of this study is to examine the properties of cellulose nanocrystals (CNCs) obtained from postconsumer polyester-cotton waste and assess the effect of different fabric structures on the extraction and these properties. To acquire nanocellulose, a thorough decolourisation pretreatment process was utilised, which involved the treatment of polyester-cotton waste with sodium dithionite and hydrogen peroxide. Consequently, the postconsumer material was then treated with an acid hydrolysis method employing a 64% (v/v) sulphuric acid solution at 50 °C for 75 min, resulting in the formation of CNCs with average yield percentages ranging from 38.1% to 69.9%. Separation of the acid from the CNC was facilitated by a centrifugation process followed by dialysis against deionised water. Uniform dispersion was then achieved using ultrasonication. A variety of analytical techniques were employed to investigate the morphological, chemical, thermal, and physical properties of the isolated CNCs. Among these techniques, attenuated total reflection-Fourier-transform infrared spectroscopy (ATR-FTIR), energy-filtered transmission electron microscopy (EF-TEM), thermogravimetric analysis (TGA), and X-ray diffraction (XRD) were utilised to analyse the CNCs. The findings indicated that the separated CNCs exhibited a rod-shaped morphology, measuring between 78 and 358 nm in length and 5 and 16 nm in diameter, and also exhibited high crystallinity (75-89%) and good thermal stability. The extracted CNCs were mixed with polyvinyl alcohol (PVA) and glycerol to assess their reinforcing effect on plastic films. The prepared composite film exhibited improved mechanical properties and thermal stability. Incorporating CNCs led to a 31.9% increase in the tensile strength and a 42.33% rise in the modulus of elasticity. The results from this research proved that CNCs can be extracted from postconsumer mixed fabrics as a potential solution to effectively address the mounting concerns surrounding waste management in the textile industry and also provide avenues for enhancing the qualities of eco-friendly composite films.

Highly Cytocompatible Polylactic Acid Based Electrospun Microfibers Loaded with Silver Nanoparticles Generated onto Chestnut Shell Lignin for Targeted Antibacterial Activity and Antioxidant Action.

Electrospun (e-spun) fibers are generally regarded as powerful tools for cell growth in tissue regeneration applications, and the possibility of imparting functional properties to these materials represents an increasingly pursued goal. We report herein the preparation of hybrid materials in which an e-spun d,l-polylactic acid matrix, to which chitosan or crystalline nanocellulose was added to improve hydrophilicity, was loaded with different amounts of silver(0) nanoparticles (AgNP) generated onto chestnut shell lignin (CSL) (AgNP@CSL). A solvent-free mechanochemical method was used for efficient (85% of the theoretical value by XRD analysis) Ag(0) production from the reduction of AgNO3 by lignin. For comparison, e-spun fibers containing CSL alone were also prepared. SEM and TEM analyses confirmed the presence of AgNP@CSL (average size 30 nm) on the fibers. Different chemical assays indicated that the AgNP@CSL containing fibers exhibited marked antioxidant properties (EC50 1.6 ± 0.1 mg/mL, DPPH assay), although they were halved with respect to those of the CSL containing fibers, as expected because of the efficient silver ion reduction. All the fibers showed high cytocompatibility toward human mesenchymal stem cells (hMSCs) representative of the self-healing process, and their antibacterial properties were tested against the pathogens Escherichia coli (E. coli), Staphylococcus epidermidis, and Pseudomonas aeruginosa. Finally, competitive surface colonization as simulated by cocultures of hMSC and E. coli showed that AgNP@CSL loaded fibers offered the cells a targeted protection from infection, thus well balancing cytocompatibility and antibacterial properties.

Application of N/P-rGO composite electrode materials and novel electrolytes in high-performance supercapacitors

Traditional graphene-based electrode materials often can not have excellent gravimetric and volumetric electrochemical properties at the same time. Furthermore, the gel electrolyte widely used at present has the disadvantages of poor water retention, easy solidification, low ionic conductivity, and narrow working temperature range during the working process. In this paper, nanocellulose/N, P co-doped reduced graphene oxide composites (NC-NPrGOs) were synthesized via a simple approach using graphene oxide (GO), ammonium dihydrogen phosphate, and nanocellulose (NC) as raw materials. Meanwhile, a new type of gel electrolyte (SNG) with renewable, wide working temperature range and ultra-high water retention properties was prepared using sodium alginate (SA), NC, GO, and potassium hydroxide as precursors. Benefiting from the unique physical and chemical properties of NC-NPrGOs, the assembled aqueous symmetric supercapacitors assembled by NC-NPrGOs present high gravimetric (303.9 F/g) and volumetric specific capacitance (416.5 F cm−3), large gravimetric (10.5 Wh kg−1) and volumetric energy density (14.6 Wh/L). Due to the multiple interactions of several components in SNG, the flexible solid-state supercapacitors (ASSC) assembled by NC-NPrGO55 and SNG deliver high specific capacitance (240.0 F/g), ultra-long cycling life, excellent bending resistance, a wide range of operating temperatures, and good regenerative performance. In summary, NC-NPrGOs and SNGs are ideal for the investigation of new energy storage devices.

Nanocrystalline cellulose as a reinforcing agent for poly (vinyl alcohol)/ gellan-gum-based composite film for moxifloxacin ocular delivery

Nanocrystalline cellulose (NCC) is a star material in drug delivery applications due to its good biocompatibility, large specific surface area, high tensile strength (TS), and high hydrophilicity. Poly(Vinyl Alcohol)/Gellan-gum-based innovative composite film has been prepared using nanocrystalline cellulose (PVA/GG/NCC) as a strengthening agent for ocular delivery of moxifloxacin (MOX) via solvent casting method. Impedance analysis was studied using the capacitive sensing technique for examining new capacitance nature of the nanocomposite MOX film. Antimicrobial properties of films were evaluated using Pseudomonas aeruginosa and Staphylococcus aureus as gram-negative and gram-positive bacteria respectively by disc diffusion technique. XRD revealed the characteristic peak of NCC and the amorphous form of the drug. Sustained in vitro release and enhanced corneal permeation of drug were noticed in the presence of NCC. Polymer matrix enhanced the mechanical properties (tensile strength 22.05 to 28.41 MPa) and impedance behavior (resistance 59.23 to 213.23 Ω) in the film due to the presence of NCC rather than its absence (16.78 MPa and 39.03 Ω respectively). Occurrence of NCC brought about good antimicrobial behavior (both gram-positive and gram-negative) of the film. NCC incorporated poly(vinyl alcohol)/gellan-gum-based composite film exhibited increased mechanical properties and impedance behavior for improved ocular delivery of moxifloxacin.

Improving the Properties of Gelatin-Based Films by Incorporation of "Pitanga" Leaf Extract and Crystalline Nanocellulose.

Biopolymer-based films can be activated by the incorporation of active compounds into their matrix. Plant extracts are rich in phenolic compounds, which have antimicrobial and/or antioxidant properties. The aim of this study was to produce gelatin-based active films and nanocomposite films incorporated with "pitanga" (Eugenia uniflora L.) leaf extract (PLE) and/or crystalline nanocellulose extracted from soybean straw (CN), and to study the physicochemical, functional, microstructural, thermal, UV/Vis light barrier, and antioxidant properties of these materials. PLE enhanced some film properties, such as tensile strength (from 30.2 MPa to 40.6 MPa), elastic modulus (from 9.3 MPa to 11.3 MPa), the UV/Vis light barrier, and antioxidant activity, in addition to affecting the microstructural, surface, and color properties. These improvements were even more significant in nanocomposites simultaneously containing PLE and CN (59.5 MPa for tensile strength and 15.1 MPa for elastic modulus), and these composites also had lower moisture content (12.2% compared to 13.5-14.4% for other treatments) and solubility in water (from 48.9% to 44.1%). These improvements may be the result of interactions that occur between PLE's polyphenols and gelatin, mainly in the presence of CN, probably due to the formation of a stable PLE-CN-gelatin complex. These results are relevant for the food packaging sector, as the activated nanocomposite films exhibited enhanced active, barrier, and mechanical properties due to the presence of PLE and CN, in addition to being entirely produced with sustainable components from natural and renewable sources.

A versatile bilayer smart packaging based on konjac glucomannan/alginate for maintaining and monitoring seafood freshness

This study introduces a novel multi-functional double-layer intelligent packaging. It focuses on developing a dual-function system capable of real-time monitoring and freshness preservation. Specifically, cellulose nanocrystalline (CNC) was obtained through acid hydrolysis, and then CNC/soybean protein isolate (CNC/SPI) complex colloid particles were prepared via antisolvent method. These particles served as stabilizers to prepare oil-in-water (O/W) cinnamon essential oil Pickering emulsion (CSCEO). The CSCEO was then integrated into the emulsified hydrophobic layer of a konjac glucomannan (Kgm) matrix through intermolecular hydrogen bonding. Finally, alginate (Alg) matrix containing alizarin (Al) as an indicator was added to construct the bilayer structure using a layer-by-layer casting strategy. The inner layer Alg/Al was the pH/NH3-responsive indicator layer, while the outer layer Kgm/CSCEO acted as the high-barrier bacteriostatic layer. The obtained dual-function, double-layer film (Alg/Al-Kgm/CSCEO), which possesses a sensitive, reversible and rapid response towards pH/NH3, shows exceptional antibacterial and antioxidant properties, as well as excellent mechanical property, light-blocking capability and hydrophobicity. For monitoring and maintaining the actual freshness of shrimp, such a bilayer packaging displays smallest change of ∆E and TVB-N (18.65 mg/100 g) even after 72 h, which further highlighting its potential in enhancing food safety and extending shelf life.