Preparation and characterization of sodium carboxymethyl cellulose/cotton linter cellulose nanofibril composite films

Sodium carboxymethyl cellulose hydrogels containing montmorillonite-NaClO2 for postharvest preservation of Chinese bayberries

Owing to their lack of outer skin, Chinese bayberries are highly susceptible to mechanical damage during picking, which accelerates bacterial invasion and rotting, shortening their shelf life. In this study, montmorillonite (MMT) was used to absorb an aqueous sodium chlorite solution embedded in a carboxymethyl cellulose sodium hydrogel after freeze drying, and the hydrogel was crosslinked by Al3+ ions. Al3+ hydrolyzed to produce H+, creating an acidic environment within the hydrogel and reacting with NaClO2 to slowly release ClO2. We prepared a ClO2 slow-release hydrogel gasket with 0.5 wt% MMT-NaClO2 and investigated its storage effect on postharvest Chinese bayberries. Its inhibition rates against Escherichia coli and Listeria monocytogenes were 98.84% and 98.96%, respectively. The results showed that the gasket preserved the appearance and nutritional properties of the berries. The antibacterial hydrogel reduced hardness loss by 26.57% and ascorbic acid loss by 46.36%. This new storage method could also be applicable to other fruits and vegetables.

Cellulose nanofiber-based multifunctional composite films integrated with zinc doped-grapefruit peel-based carbon quantum dots

This study aimed to develop a multifunctional active composite film to extend the shelf life of minced pork. The composite film was prepared by incorporating zinc-doped grapefruit peel-derived carbon quantum dots (Zn-GFP-CD) into a cellulose nanofiber (CNF) matrix. The resulting film significantly improved UV-blocking properties from 39.0 % to 85.7 % while maintaining the film transparency. Additionally, the CNF/Zn-GFP-CD5% composite film exhibits strong antioxidant activity with ABTS and DPPH radical scavenging activities of 99.8 % and 77.4 %, respectively. The composite film also showed excellent antibacterial activity against both Gram-negative and Gram-positive bacteria. When used in minced pork packaging, the composite films effectively inhibit bacterial growth, maintaining bacterial levels below 7 Log CFU/g after 15 days and sustaining a red color over a 21-day storage period. Additionally, a significant reduction in the lipid oxidation of the minced pork was observed. These CNF/Zn-GFP-CD composite films have a great potential for active food packaging applications to extend shelf life and maintain the visual quality of packaged meat.

Safe and sustainable food packaging: Argemone albiflora mediated green synthesized silver-carrageenan nanocomposite films

Silver-Carrageenan (Ag/Carr) nanocomposite film for food packing application by the green method using Argemone albiflora leaf extract has been developed in this study. Different plant parts of Argemone albiflora (blue stem prickly poppy) are used all over the world for the treatment of microbial infections, jaundice, skin diseases etc. GC-MS analysis was used to examine the phytochemical found in the Argemone albiflora leaf extract which reduces the metal ions to nanoscale. The biopolymer employed in the synthesis of nanocomposite film was carrageenan, a natural carbohydrate (polysaccharide) extracted from edible red seaweeds. We developed a food packing that is biodegradable, eco-friendly, economical and free from harmful chemicals. These films possess better UV barrier and mechanical and antimicrobial properties with 1 mM AgNO3 solution. The presence of silver nanoparticles in the carrageenan matrix was evident from FESEM. The mechanical properties were analysed by a Universal testing machine (UTM) and different properties like water vapour permeability (WVP), moisture content (MC) and total soluble matter (TSM) important for food packing applications were also analysed. The antimicrobial properties of the synthesized film samples were studied against E. coli and S. aureus pathogenic bacteria. These films were employed for the storage of cottage cheese (dairy product) and strawberries (fruit). This packing increased the shelf life of the packed food effectively. Ag/Carr films are biodegradable within four weeks.

Efficient photocatalytic remediation of lerui acid brilliant blue dye using radiation- prepared carboxymethyl cellulose/acrylic acid hydrogel supported by ZnO@Ag

Organic dye pollution from textiles and other industries presents a substantial risk to people and aquatic life. The use of photocatalysis to decolorize water using the strength of UV light is one of the most important remediation techniques. In the present study, a novel nanocomposites hydrogel including carboxymethyl cellulose (CMC), acrylic acid (AAc), Zinc oxide (ZnO), and silver (Ag) nanoparticles was produced using an eco-friendly γ-irradiation technique for photocatalytic decolorization applications. ZnO and Ag nanoparticles were distributed in the CMC/AAc hydrogel matrix without significant aggregation. SEM, XRD, EDX, TEM, and FTIR analyses were used to assess the physicochemical characteristics of the nanocomposite samples. Carboxymethyl cellulose/acrylic acid/Zinc oxide doped silver (CMC/PAAc/ZnO@Ag) nanocomposite hydrogels were developed and utilized in the photocatalytic decolorization of the lerui acid brilliant blue dye (LABB) when exposed to ultraviolet (UV) radiation. UV- Vis spectrophotometry was utilized to analyze the optical properties of the produced nanostructure. Regarding the decolorization of the LABB, the impacts of operational variables were investigated. The optimum conditions for decolorization (93 %) were an initial concentration of 50 mg/L, pH = 4, catalyst dosage of 50 g/L, and exposure time of 90 min. The results illustrated that the LABB acidic dye from wastewater was remarkably decolored.

Resource utilization of wastepaper and bentonite: Cu(II) removal in the aqueous environment

Contamination of heavy metals has always been a pressing concern. The dry-wet alternately treated carboxymethylcellulose bentonite (DW-CB) was successfully prepared by intercalating bentonite (BT) with carboxymethyl cellulose (CMC) obtained by solvent processes using enzymatically digested wastepaper as cellulosic raw material, and the adsorption capacity of Cu2+ on DW-CB in aqueous solution was investigated. A 98.18 ± 2.31 % removal efficiency was achieved by 4 g/L of DW-CB after 8 h in a solution containing 100 mg/L of Cu2+, which were 4.1 times and 1.5 times of that of BT and adsorbent prepared without alternating dry-wet process, respectively. The introduction of -COOH groups during the preparation of DW-CB enhanced the electrostatic interaction between DW-CB and Cu2+, which was the main driving force for Cu2+ removal. The pseudo-first-order kinetic model and Langmuir model better described the adsorption process and adsorption capacity of Cu2+ on DW-CB. DW-CB still showed high removal of Cu2+ (19.61 ± 0.99 mg/g) in the presence of multiple metal ions, while exhibiting the potential for removal of Zn2+, Mg2+ and K+, especially Mg2+ (22.69 ± 1.48 mg/g). However, the interactions of organics with Cu2+ severely affected the removal of Cu2+ by DW-CB (removal efficiency: 17.90 ± 4.17 % - 95.33 ± 0.27 %). In this study, an adsorbent with high targeted adsorption of Cu2+ was prepared by utilizing wastepaper and BT, which broadened the way of wastepaper resource utilization and had good economic and social benefits.

Antibacterial Activity of Modified Sesbania Gum Composite Film and Its Preservation Effect on Wampee Fruit (Clausena lansium (Lour.) Skeels)

The primary challenges in fruit and vegetable preservation include extending storage duration while preserving sensory quality and nutritional value. In this study, sesbania gum (SG) was oxidized to prepare oxidized sesbania gum (OSG). An OSG/ZnO composite film was subsequently prepared, combining OSG, sodium carboxymethyl cellulose (CMC), and nano-zinc oxide (nano-ZnO). The preparation technology was determined via a response surface optimization experiment. When the addition amount of nano-ZnO exceeded 0.3 mg/mL, the composite films exhibited an antibacterial rate of over 90% against E. coli and S. aureus. For wampee (Clausena lansium (Lour.) Skeels) preservation, a OSG/ZnO-0.3 film was directly applied as a coating. The findings demonstrated favorable results in terms of the rate of rotting, soluble solids, and titrable acidity, effectively prolonging wampee fruit storage. This suggests the potential of an OSG composite film with nano-ZnO as a promising fruit packaging material, thereby expanding the application of SG and wampee fruit preservation.

Cellulose nanocrystals extracted from rice husk using the formic/peroxyformic acid process: isolation and structural characterization

Cellulose derived from biomass is a renewable resource with numerous applications. Using formic/peroxyformic acid at atmospheric pressure, cellulose nanocrystals (CNC) were isolated from rice husk (RH) in this study. This method was an excellent way to get rid of lignin and hemicelluloses from RH. The cellulose was subsequently acid hydrolyzed by H2SO4 (64%) for 30 minutes at 45 °C. The chemical and microstructure analysis showed that the lignin and hemicellulose contents of raw RH had been eliminated, and the crystallinity content of CNC was 67.16%. According to transmission electron microscopy (TEM) morphological analysis, CNC measured 19 ± 3.3 nm in diameter, 195 ± 24 nm in length, and 10.2 ± 6.8 in aspect ratio. The thermal stability of RH and CNC was also investigated using thermogravimetric analysis (TGA). These encouraging findings demonstrated the potential for reusing RH agricultural waste to create CNC and include nanocomposites as a reinforcing material.

Sodium alginate/carboxymethyl cellulose films embedded with liposomes encapsulated green tea extract: characterization, controlled release, application

To maintain the freshness of the fruit during storage, sodium alginate/carboxymethyl cellulose films embedded with pH-senstive liposomes encapsulated green tea extract were developed (SA/CMC/TP-Lip). An orthogonal design was used to optimise the preparation of TP-Lip and SA/CMC/TP-Lip was prepared through response surface. The stability of TP-Lip structure was measured. The morphology of SA/CMC/TP-Lip was characterised by SEM, and the mechanical properties and oxidation resistance of films were measured. Special attention was paid to the pH sensitivity of TP-Lip and the improvement of film properties. The zeta potential and encapsulation rate of TP-Lip were -45.85 ± 2.13 mV and 61.45 ± 0.23%. The average release rate of TP encapsulated into TP-Lip at pH 3 was 41.08%, an increase of 23.07% over pH 6 during 12 h. SEM and FTIR showed that TP-Lip was structurally stable and had good compatibility with SA/CMC. Tensile strength was increased by 30.55% and DPPH radical scavenging capacity was increased by 7.16% with the addition of TP-Lip. SA/CMC/TP-Lip is applied to blueberries to reduce their weight loss and improve the loss of freshness of blueberries during storage. Thus, SA/CMC/TP-Lip could provide a new way to extend active packaging materials and maintain fruit freshness during storage.

Preparation and activity of sodium carboxymethyl cellulose (CMC-Na) and Metarhizium rileyi ZHKUMR1 composite membrane

Improving the adhesion capability of Metarhizium rileyi ZHKUMR1 on leaves enabled by the combination with Carboxymethyl Cellulose (CMCNa) materials is feasible to improve the utilization rate of Metarhizium rileyi. Herein, the CMC-Na-ZHKUMR1 membrane was prepared by simply mixing Carboxymethyl Cellulose (CMCNa) with Metarhizium rileyi. Through compatibility test, it was found that the inhibition rates of spore germination and mycelial growth of ZHKUMR1 were only 1.51 % and 3.13 % when the concentration of Carboxymethyl Cellulose (CMCNa) was 0.5 %. By adding 2 % of Carboxymethyl Cellulose (CMCNa) under UV irradiation for 30 min, the protective rate of spore germination of ZHKUMR1 was up to ~12.44 %, where the wettability on corn leaves was achieved and the retention of ZHKUMR1 spores on corn leaves was increased. After indoor activity determination, it was found that after 3 min of simulated rain washing, the lethal rate of corn leaves pretreated with CMC-Na-ZHKUMR1 on the 2nd instar larvae of Spodoptera frugiperda was 46.67 %, which was much higher than that of ZHKUMR1 spore suspension alone. This work clearly showed that Carboxymethyl Cellulose (CMCNa) effectively improved the field application effect of Metarhizium rileyi ZHKUMR1, and this strategy provided guidance for improving the field efficacy of Metarhizium rileyi ZHKUMR1.

Isolation of cellulose nanofibers from rapeseed straw via chlorine-free purification method and its application as reinforcing agent in carboxymethyl cellulose-based films

In this study, cellulose nanofibers (CNFs) were successfully isolated from rapeseed straw (RS) whose valorization has been rarely investigated to date. A combined bleaching method without chlorine was applied for the purification of cellulose fibers, previously unexplored for RS. Chemical composition analysis and Fourier-transform infrared spectroscopy (FTIR) indicated that the purification method eliminated hemicellulose and reduced lignin content from 24.4 % to 1.8 %. The isolation of CNFs was performed using sulfuric acid hydrolysis under different acid concentrations (55 and 60 % v/v) and hydrolysis times (15, 30, and 45 min). The isolated CNFs were characterized by FTIR, X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The formation of CNFs was confirmed by a significant increase in crystallinity index from 46.45 % of RS to >79.41 % of CNFs, depending on acid concentration and isolation duration. Carboxymethyl cellulose (CMC) films with different contents of CNFs were prepared by casting method. The mechanical properties and cytotoxicity of the prepared films were investigated. The CNFs obtained from RS via a chlorine-free purification method showed promising results for their usage as reinforcement in CMC matrix and film fabrication for various applications such as transdermal medicine and food packaging.

Effect of the Addition of Fique Bagasse Cellulose Nanoparticles on the Mechanical and Structural Properties of Plastic Flexible Films from Cassava Starch

One of the activities most representative of the agricultural sector in Colombia is the production of biodegradable fique fiber. The efficiency of the defiberization process of the fique leaves is very low since a mere 4% of the total weight of the leaf (cabuya) is used and marketed. The remaining 96%, composed of fique juice and bagasse, is considered to be waste and discarded, impacting the environment. The aim of this work was to study fique bagasse as a source of cellulose nanoparticles (CNCs). CNCs were obtained by acid hydrolysis and added at 10% to films made from cassava thermoplastic starch (TPS) by the casting method. Structural changes in the CNCs, TPS, and their mixtures were characterized by FTIR-ATR and their morphology and particle size by SEM and TEM microscopy, respectively. Thermal properties were analyzed using DSC and TGA, along with their effect on mechanical properties. Changes in the FTIR spectra indicated that the chemical method adequately removed hemicellulose and lignin from the fiber surface of fique bagasse. The CNCs showed a diameter and length of 7.5 ± 3.9 and 52.7 ± 18.1 nm, respectively, and TPS 10% CNC obtained an increase in mechanical strength of 116%. The obtainment of CNCs from lignocellulosic materials can thus be viewed as a favorable option for the subsequent reinforcement of a polymeric matrix.

Fabrication of carboxymethyl chitosan films for cheese packaging containing gliadin-carboxymethyl chitosan nanoparticles co-encapsulating natamycin and theaflavins

In this study, gliadin-carboxymethyl chitosan composite nanoparticles (GC NPs) co-encapsulated natamycin (Nata) and theaflavins (TFs) were constructed and added as an antioxidant, antifungal, and structural enhancer to carboxymethyl chitosan (CMCS) films. The stabilized GC NPs with a particle size of 160.7 ± 2.8 nm, a zeta potential of -29.0 ± 0.9 mV, and a protein content in the supernatant of 96 ± 1 % could be fabricated. Tests of pH and salt ions showed that the stability of NPs dispersion was based on electrostatic repulsion. Co-encapsulation of TFs enhanced the photostability of Nata and the antioxidant activity of the NPs dispersion. The interactions between gliadin with Nata and TFs were studied by molecular simulations. As a functional additive, the addition of Nata/TFs-GC NPs could improve the optical properties, mechanical properties, water-blocking capability, and antifungal and antioxidant activities of the CMCS films. The in-vivo test showed that the functional film could be used to inhibit the growth of Aspergillus niger on cheese.

Preparation of Nanocellulose from Coffee Pulp and Its Potential as a Polymer Reinforcement

Coffee is one of the most valued agricultural products regarding its high commercialization rate. During the production of coffee beans, coffee pulp is obtained as one of the main byproducts with a cellulose content of more than 30% of dry weight. This research focused on the value-added potential of coffee pulp fiber as the reinforcement in composite materials. The nanocellulose coffee pulp (NCP) from the coffee pulp (CP) was prepared and subsequently used as a filler to reinforce the polyvinyl alcohol (PVA) matrix for the improvement of PVA composite properties. The CP was treated via alkali and bleaching treatment before the production of NCP using the acid hydrolysis treatment. The TEM result of NCP showed the successful preparation of NCP with an average diameter of 16.03 ± 4.70 nm with increasing crystallinity size and crystallinity index. The effect of glycerol (G) in the PVA matrix was observed. The result showed that glycerol had a play-role as a plasticizer for increased flexibility and decreased hardness and brittleness of PVA nanocomposite film. The nanocomposite film of PVA/G/NCP was fabricated with various ratios of NCP through the casting method. It was shown that the physical properties were improved with the presence of NCP in the PVA matrix compared to the neat PVA film.

Exploring the Potential of Seaweed Derivatives for the Development of Biodegradable Plastics: A Comparative Study

Biodegradable films made from biopolymer materials have the potential to replace conventional plastics, which can reduce waste disposal problems. This study aims to explore the potential of different seaweed derivate films consisting of 2% (w/w) of kappaphycus alverezi (KA), kappa carrageenan (KC), refined carrageenan (RC) and semi-refined carrageenan (SRC) as bio-based materials with 0.9% (w/w) glycerol (G), and reinforced with different concentrations of cellulose nanofibers (CNFs) derived from palm waste. A characterization of the glycerol-plasticized seaweed derivatives containing 0, 5, 10, and 15% (v/w) cellulose nanofiber is carried out. The CNFs were studied based on their mechanical, physical and thermal properties including mechanical properties, thickness, moisture content, opacity, water solubility, water vapor permeability and thermal stability. The hydrogen bonding was determined using the DFT calculation generated by Gauss view software version 9.6. The KA + G + 10%CNF film exhibited a surface with slight cracks, roughness, and larger lumps and dents, resulting in inferior mechanical properties (18.50 Mpa), making it unsuitable for biofilm production. The KC + G + 10%CNF film exhibited mechanical properties 24.97 Mpa and water vapor permeability of 1.42311 × 10^-11 g s^-1 m^-1 Pa^-1. The RC/G/10%CNF film displayed the highest TS (48.23 MPa) and water vapor permeability (1.4168 × 10^-11 g s^-1 m^-1 Pa^-1), but it also had higher solubility in water (66%). In contrast, the SRC + G + 10%CNF film demonstrated excellent mechanical properties (45.98 MPa), low water solubility (42.59%), low water vapor permeability (1.3719 × 10^-11 g s^-1 m^-1 Pa^-1), and a high decomposition temperature (250.62 °C) compared to KA, KC and RC. These attributes develop films suitable for various applications, including food packaging with enhanced properties and stability.

Large-Scale Preparation of Carboxylated Cellulose Nanocrystals and Their Application for Stabilizing Pickering Emulsions

Cellulose nanocrystals (CNCs) with varied unique properties have been widely used in emulsions, nanocomposites, and membranes. However, conventional CNCs for industrial use were usually prepared through acid hydrolysis or heat-controlled methods with sulfuric acid. This most commonly used acid method generally suffers from low yields, poor thermal stability, and potential environmental pollution. Herein, we developed a high-efficiency and large-scale preparation strategy to produce carboxylated cellulose nanocrystals (Car-CNCs) via carboxymethylation-enhanced ammonium persulfate (APS) oxidation. After carboxymethylation, the wood fibers could form unique "balloon-like" structures with abundant exposed hydroxy groups, which facilitated exfoliating fibril bundles into individual nanocrystals during the APS oxidation process. The production process under controlled temperature, time period, and APS concentrations was optimized and the resultant Car-CNCs exhibited a typical structure with narrow diameter distributions. In particular, the final Car-CNCs exhibited excellent thermal stability (≈346.6 °C) and reached a maximum yield of 60.6%, superior to that of sulfated cellulose nanocrystals (Sul-CNCs) prepared by conventional acid hydrolysis. More importantly, compared to the common APS oxidation, our two-step collaborative process shortened the oxidation time from more than 16 h to only 30 min. Therefore, our high-efficiency method may pave the way for the up-scaled production of carboxylated nanocrystals. More importantly, Car-CNCs show potential for stabilizing Pickering emulsions that can withstand changeable environments, including heating, storage, and centrifugation, which is better than the conventional Sul-CNC-based emulsions.

Physico-chemical and antimicrobial characteristics of novel biodegradable films based on gellan and carboxymethyl cellulose containing rosemary essential oil

The purpose of the current investigation was to produce a novel functional composite biodegradable film by Gellan (Gla) and Carboxymethyl cellulose (CMC) biopolymers containing rosemary essential oils (REO) and evaluate their physicochemical and antimicrobial features. The film containing 5 % REO, due to its better mechanical properties (UTS = 13.44 ± 0.30 Mpa and SB = 21.14 ± 1.15 %) compared to other emulsified samples containing REO, was selected as the optimal film. Furthermore, it had less water vapor permeability (WVP = 6.60 ± 0.31 (g/mhPa) × 10^-8) in comparison to control sample (8.21 ± 0.10 (g/mhPa) × 10^-8) and the best color properties among the samples. The Scanning Electron Microscopy (SEM) images didn't show the phenomenon of agglomeration and point accumulation of REO. Also, 5 % of REO contributed to the increased compactness of the film in comparison to the film without the REO. Based on the results of Fourier-transform infrared spectroscopy (FTIR) spectra, no new chemical bonds were created by adding REO to the biopolymer substrate, and the REO was well dispersed and distributed among the Gla-CMC chains throughout the film substrate. Adding 5 % REO showed antioxidant effects. Considering the antimicrobial tests, all films containing REO had antimicrobial effects against the Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, and Pseudomonas fluorescens bacterial strains.

Cellulose nanofiber-based multifunctional films integrated with carbon dots and anthocyanins from Brassica oleracea for active and intelligent food packaging applications

A new generation of carbon dot-based active and intelligent packaging films with UV blocking, antibacterial, and real-time sensing potentials was fabricated using Brassica oleracea (BO) extract. The cellulose nanofiber (CNF) was used to prepare the multifunctional intelligent nanocomposite film integrated with BO anthocyanins (BOA) and BO-biowaste-derived carbon dots (BO-CDs). The incorporation of 1.5 % BO-CD and 6 % BOA in the CNF matrix improved the physicochemical and UV blocking (>189 % increase) properties of the fabricated films. The synthesized BO-CD exhibits high fluorescence, UV absorption, antibacterial and antioxidant functions. It showed strong radical scavenging activity against ABTS (~90 %) and DPPH (~80 %) compared to the neat CNF film. Scanning electron microscopy and X-ray photoelectron spectroscopy (XPS) have shown enhanced compatibility and elemental composition of the BO-CDs/BOA additives in the CNF-polymer matrix. Packaging tests showed that the prepared film worked efficiently and non-destructively and was able to monitor the freshness of minced pork, fish, and shrimp in real-time through a distinct visual change from red to colorless/yellow during storage at 25 °C for 48 h. Active and intelligent films developed based on CNF/BO-CDs/BOA are expected to be applied as multifunctional packaging materials that can indicate quality changes and extend the shelf life of packaged perishable foods.

Nano-chitin: Preparation strategies and food biopolymer film reinforcement and applications

Current trends in food packaging systems are toward biodegradable polymer materials, especially the food biopolymer films made from polysaccharides and proteins, but they are limited by mechanical strength and barrier properties. Nano-chitin has great economic value as a highly efficient functional and reinforcing material. The combination of nano-chitin and food biopolymers offers good opportunities to prepare biodegradable packaging films with enhanced physicochemical and functional properties. This review aims to give the latest advances in nano-chitin preparation strategies and its uses in food biopolymer film reinforcement and applications. The first part systematically introduces various preparation methods for nano-chitin, including chitin nanofibers (ChNFs) and chitin nanocrystals (ChNCs). The nano-chitin reinforced biodegradable films based on food biopolymers, such as polysaccharides and proteins, are described in the second part. The last part provides an overview of the current applications of nano-chitin reinforced food biopolymer films in the food industry.

Enhanced antibacterial effect and biodegradation of coating via dual-in-situ growth based on carboxymethyl cellulose

The lack of antimicrobial effect of commercial paper coating for food packaging makes it difficult to prevent food spoilage and harms the environment by non-biodegradation. Herein, carboxymethyl cellulose (CMC) provides negatively charged sites for anchoring Ag⁺ and Zn²⁺ to grow AgNPs and ZIF-8 in situ on its molecular chains. The ZIF-8/AgNPs@CMC paper coating has excellent synergistic antibacterial activity to prolong the shelf-life of food. It not only has good thermal stability but binds closely to the paper and its adhesion force reaches 628.9 nN. Besides, the ZIF-8/AgNPs@CMC coated paper has better mechanical properties, water vapor barrier, and resists water solubility. Interestingly, due to the confinement effect of ZIF-8, the cumulative release of AgNPs after 168 h is only 2.66 % to avoid possible food safety risks. Especially, the coating can be almost biodegraded in the soil after 30 days, which provides the possibility to replace the non-biodegradable coatings in food packaging.

Anisotropic Wooden Electromechanical Transduction Devices Enhanced by TEMPO Oxidization and PDMS

In order to increase the number and contact probability of electric dipole on cellulose, acid and alkali treatment was employed to extract hemicellulose and lignin from original wood to gain a highly oriented cellulose frame. The combined means with 2,2,6,6-tetramethylpiperidine-1-oxyl-NaBr-NaClO oxidation and impregnation of PDMS with compression was subsequently used to enhance its mechanical performance and electromechanical conversion. The assembled wooden electromechanical device (10 mm × 10 mm × 1 mm) exhibits the maximum open-circuit voltage (V _OC) of 11.75 V and short-circuit current (I _SC) of 211.01 nA as stepped by foot. It can be sliced to fabricate a flexible sensor with high sensitivity displaying V _OC of 2.88 V and I _SC of 210.09 nA under the tapped state. Its highly oriented wood fiber makes it display significant anisotropy in terms of mechanical and electromechanical performance for multidirectional sense. This strategy will exactly provide reference for developing other high-performance piezoelectric devices.

Preparation of garlic stem cellulose nanocrystal/leaf extract/chitosan film for black garlic preservation by electrostatic spraying

In this study, a novel active chitosan (CH) packaging film that incorporates garlic leaf extract (GL) and stem cellulose nanocrystals (CNC) was prepared. The addition of CNC to the CH film increased its tensile strength, hydrophilicity, thermal stability, and water/oxygen barrier and decreased its water contact angle and weight-loss rate, while the addition of GL greatly enhanced its antioxidant and antibacterial activities. SEM and AFM analyses showed that the CNC agglomerates and deposits in the lower layer and the surface roughness of the film was the highest at 1.2 % concentration. The optimal composition of the film was determined to be 0.8 % CNC and 4 % GL by the fuzzy mathematics evaluation method. Then, black garlic was preserved with the optimized coating by electrostatic spraying and was found to slow water loss and migration, while its excellent antioxidant activities decreased the degree of browning during 90 d of storage.

Cellulose nanocrystals isolated from corn leaf: straightforward immobilization of silver nanoparticles as a reduction catalyst

As the most abundant natural biopolymer on earth, celluloses have long-term emerged as a capable platform for diverse purposes. In the context of metal nanoparticles applied to catalysis, the alternatives to traditional catalyst supports by using biomass-derived renewable materials, likely nanocelluloses, have been paid a great effort, in spite of being less exploited. In this study, cellulose nanocrystals were isolated from corn leaf via chemical treatment involving alkalizing, bleaching and acid hydrolysis. The crystallinity of obtained cellulose was evaluated in each step, focusing on the effects of reactant concentration and reaction time. Cellulose nanocrystals were characterized by powder X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), evidencing the presence of cellulose nanospheres (crystallinity index of 67.3% in comparison with 38.4% from untreated raw material) in the size range of 50 nm. Without using any additional surfactants or stabilizers, silver nanoparticles (AgNPs) well-dispersed on the surface of cellulose nanocrystals (silver content of 5.1 wt%) could be obtained by a simple chemical reduction using NaBH4 at room temperature. The catalytic activity was evaluated in the selective reductions of 4-nitrophenol towards 4-aminophenol and methyl orange towards aromatic amine derivatives in water at room temperature. The effects of catalyst amount and reaction time were also studied in both reduction processes, showing near-quantitative conversions within 5 minutes and obeying the pseudo-first-order kinetics, with the apparent kinetic rate constants of 8.9 × 10-3 s-1 (4-nitrophenol) and 13.6 × 10-3 s-1 (methyl orange). The chemical structure of the catalytic system was found to be highly stable during reaction and no metal leaching was detected in reaction medium, evidencing adaptability of cellulose nanocrystals in immobilizing noble metal nanoparticles.

Development of Smart Bilayer Alginate/Agar Film Containing Anthocyanin and Catechin-Lysozyme

Smart packaging can provide real-time information about changes in food quality and impart a protective effect to the food product by using active agents. This study aimed to develop a smart bilayer film (alginate/agar) with a cellulose nanosphere (CNs) from corncob. The bilayer films were prepared using 1.5% (w/w) sodium alginate with 0.25% (w/v) butterfly pea extract incorporated (indicator layer) and 2% (w/w) agar containing 0.5% (w/v) catechin−lysozyme (ratio 1:1) (active layer). The CNs were incorporated into the alginate layer at different concentrations (0, 5, 10, 20, and 30% w/w-based film) in order to improve the film’s properties. The thickness of smart bilayer film dramatically increased with the increase of CNs concentration. The inclusion of CNs reduced the transparency and elongation at break of the smart bilayer film while increasing its tensile strength (p < 0.05). The integration of CNs did not significantly affect the solubility and water vapor permeability of the smart bilayer film (p > 0.05). The smart bilayer film displayed a blue film with a glossy (without CNs) or matte surface (with CNs). The developed bilayer film shows excellent pH sensitivity, changing color at a wide range of pHs, and has a good response to ammonia and acetic acid gases. The film possesses exceptional antimicrobial and antioxidant activities. The integration of CNs did not influence the antibacterial activity of the film, despite the presence of a higher level of DPPH in film containing CNs. The smart bilayer film was effectively used to monitor shrimp freshness. These findings imply that smart bilayer films with and without CNs facilitate food safety and increase food shelf life by monitoring food quality.

3D-Printed Pectin/Carboxymethyl Cellulose/ZnO Bio-Inks: Comparative Analysis with the Solution Casting Method

Bio-inks consisting of pectin (Pec), carboxymethyl cellulose (CMC), and ZnO nanoparticles (ZnO) were used to prepare films by solution casting and 3D-printing methods. Field emission scanning electron microscopy (FE-SEM) was conducted to observe that the surface of samples made by 3D bioprinter was denser and more compact than the solution cast samples. In addition, Pec/CMC/ZnO made by 3D-bioprinter (Pec/CMC/ZnO-3D) revealed enhanced water vapor barrier, hydrophobicity, and mechanical properties. Pec/CMC/ZnO-3D also showed strong antimicrobial activity within 12 h against S. aureus and E. coli O157: H7 bacterial strains compared to the solution cast films. Further, the nanocomposite bio-inks used for 3D printing did not show cytotoxicity towards normal human dermal fibroblast (NDFB) cells but enhanced the fibroblast proliferation with increasing exposure concentration of the sample. The study provided two important inferences. Firstly, the 3D bioprinting method can be an alternative, better, and more practical method for fabricating biopolymer film instead of solution casting, which is the main finding of this work defining its novelty. Secondly, the Pec/CMC/ZnO can potentially be used as 3D bio-inks to fabricate functional films or scaffolds and biomedical applications.

Chemical and Enzymatic Fiber Modification to Enhance the Mechanical Properties of CMC Composite Films

Carboxymethyl cellulose (CMC) is a cellulose derivative that can be obtained from wood, bamboo, rattan, straw, and other cellulosic materials. CMC can be used to produce biofilms for many purposes, but the properties of these resulting films make them unsuitable for some applications. The effects of three kinds of plant fiber addition on CMC film properties was investigated using CMC derived from eucalyptus bark cellulose. Tensile strength (TS) and elongation at break (EB) of CMC/sodium alginate/glycerol composite films were 26.2 MPa and 7.35%, respectively. Tensile strength of CMC composite films substantially increased, reaching an optimum at 0.50 g of fiber. The enhancement due to industrial hemp hurd fiber on CMC composite films was more obvious. Pretreatment with hydrogen peroxide (H₂O₂) and glacial acetic acid (CH₃COOH) produced films with a TS of 35.9 MPa and an EB of 1.61%. TS values with pectinase pretreated fiber films was 41.3 MPa and EB was 1.76%. TS of films pretreated with pectinase and hemicellulase was 45.2 MPa and EB was 4.18%. Chemical and enzymatic treatment both improved fiber crystallinity, but film tensile strength was improved to a greater extent by enzymatic treatment. Surface roughness and pyrolysis residue of the film increased after fiber addition, but Fourier transform infrared spectroscopy (FTIR), opacity, and water vapor transmission coefficients were largely unchanged. Adding fiber improved tensile strength of CMC/sodium alginate/glycerol composite films and broadened the application range of CMC composite films without adversely affecting film performance.

Development of soy-based nanocomposite film: Modeling for barrier and mechanical properties and its application as cheese slice separator

In the current study, soybean aqueous extract (SAE)-based nanocomposite film was developed by incorporating cellulose nanofiber (CNF) at various concentrations (0-10%). Effect of nanoreinforcement on essential properties of the nanocomposite film such as barrier, mechanical, water affinity, and optical properties were evaluated. Homogeneous films with improved barrier and mechanical properties were observed until 6% CNF, beyond which considerable reduction in desirable properties was noticed due to nanoparticle's agglomeration effect. Furthermore, the prediction of the mechanical and barrier properties of nanocomposite film was performed with mathematical models such as modified Halpin-Tsai and modified Nielsen equations, respectively. The model-fitting results reveal that the theoretically predicted values were in close agreement with the experimental values. Hence, these models were well suited for predicting respective properties. Model prediction also implies that the increase in the aspect ratio of fillers can considerably cause a reduction in water vapor permeability and improvement in mechanical properties. Suitability of developed film as cheese slice separator was evaluated: they had equivalent outcomes in terms of easiness in slice separation and wholeness of slices after separation compared to the commercial material.

A Comprehensive Characterization of Biodegradable Edible Films Based on Potato Peel Starch Plasticized with Glycerol

Potatoes are a source of starch, which is an eco-friendly alternative to petrochemicals in plastic production. Increasing potato production also creates agricultural waste that could be converted to potato peel starch (PPS) and developed as films. A response surface method approach was employed to optimize the bioconversion of PPS (2, 4, and 6% w/v) and compared with carboxymethyl cellulose (CMC)-based films. The microstructure analysis of PPSF showed increased thickness, decreased swelling power, water solubility, and vapor permeability, which were linked to increased molecular interactions as a function of PPS increments. However, low-starch PPSF exhibited high transparency, good mechanical properties, and thermal stability (high melting temperature), pliability, and accelerated seawater and soil biodegradation (~90%: 20 and 50 days, respectively). All films exhibited thermal stability at >100 °C and retained similar amorphous characteristics, evidenced by their flexibility, which confirmed the potential use for PPS in packaging perishable and cooled foods.

The Improved Properties of Carboxymethyl Bacterial Cellulose Films with Thickening and Plasticizing

This study aims to improve the thermal stability and mechanical properties of carboxymethyl bacterial cellulose (CMBC) composite films. Experiments were conducted by preparing bacterial cellulose (BC) into CMBC, then parametrically mixing sodium alginate/starch/xanthan gum/gelatin and glycerin/sorbitol/PEG 400/PEG 6000 with CMBC to form the film. Scanning electron microscopy, X-ray diffractometry, infrared spectroscopy, mechanical tests, and thermogravimetric analysis showed that the composite films had better mechanical properties and thermal stability with the addition of 1.5% CMBC (% v/v), 1% sodium alginate, and 0.4% glycerin. Tensile strength was 38.13 MPa, the elongation at break was 13.4%, the kinematic viscosity of the film solution was 257.3 mm²/s, the opacity was 4.76 A/mm, the water vapor permeability was 11.85%, and the pyrolysis residue was 45%. The potential causes for the differences in the performance of the composite films were discussed and compared, leading to the conclusion that CMBC/Sodium alginate (SA)/glycerin (GL) had the best thermal stability and mechanical properties.

Isolation and Characterization of Cellulose Nanocrystals from Date Palm Waste

This study presents the isolation, characterization, and kinetic analyses of cellulose nanocrystals (CNCs) from date palm waste in the United Arab Emirates. After bleaching date palm stem waste with acidified NaClO₂ and delignification via NaOH treatments, cellulose was extracted. Mineral acid hydrolysis (62 wt % H₂SO₄) was performed at 45 °C for 45 min to produce crystalline nanocellulose. Fourier transform infrared (FTIR) and chemical composition analysis confirmed the removal of noncellulosic constituents. The crystallinity index increased gradually with chemical treatments, according to the obtained X-ray diffraction (XRD) results. Thermogravimetric analysis and differential scanning calorimetry results revealed that the CNC has high thermal stability. The Coats-Redfern method was used to determine the kinetic parameters. The kinetic analysis confirmed that CNC has more activation energy than cellulose and thus confirms its compact and resistive crystalline structure. This has been attributable to the stronger hydrogen bonding in CNC crystalline domains than that in cellulose crystalline domains. Scanning electron microscopy revealed that lignin and hemicellulose were eliminated after chemical pretreatments, and CNC with a rodlike shape was obtained after hydrolysis. Moreover, transmission electron microscopy confirmed the nanoscale of crystalline cellulose. ζ potential analysis indicated that the CNC afforded a stable suspension (-29.27 mV), which is less prone to flocculation. Kinetic analyses of cellulose and cellulose nanocrystals isolated from date palm waste are useful for making composites and designing selective pyrolysis reactors.

Composites of cellulose nanocrystals in combination with either cellulose nanofibril or carboxymethylcellulose as functional packaging films

Cellulose nanocrystals (CNC) were mixed with either cellulose nanofibril (CNF) or carboxymethylcellulose (CMC) in variable proportions (0/100, 20/80, 40/60, 50/50, 60/40, 80/20 and 100/0) to obtain cast films with acceptable barrier and mechanical properties as replacements for food packaging plastics. Both CNF and CMC improved tensile strength, elongation, UV opacity, air resistance, hydrophobicity (WCA-water contact angle), water vapor transmission rate (WVTR) and oxygen impermeability in pure CNC. WVTR and oxygen permeability were strongly dependent on relative humidity (RH). Interestingly, the greatest effect on WVTR was observed at RH = 90% in films containing CMC in proportions above 60%. CMC- and CNF-containing films had oxygen impermeability up to an RH level of 80% and 60%, respectively. The previous effects were confirmed by food packaging simulation tests, where CMC-containing films proved the best performers. The composite films studied were biodegradable-which constitutes a major environmental related advantage-to an extent proportional to their content in CMC or CNF.

Antimicrobial, antioxidant, and pH-sensitive polyvinyl alcohol/chitosan-based composite films with aronia extract, cellulose nanocrystals, and grapefruit seed extract

Aronia or black chokeberry (Aronia melanocarpa), cellulose nanocrystals (CNCs), and grapefruit seed extract (GSE) were used for the preparation of multifunctional polyvinyl alcohol/chitosan (PVA/CS) composite films with pH-sensitivity, antimicrobial, antioxidant, and UV-barrier properties. Aronia extract showed total phenolic content of 297 ± 0.5 μg GAE/mg aronia extract, potent antioxidant activity, and high color-response efficiency. Isolated CNCs showed a needle-like structure with a length of 470 nm and a width of 35 nm. The tensile strength of the PVA/CS composite film increased by 74% after the incorporation of CNCs, whereas the film flexibility was enhanced by 75% after adding GSE. The PVA/CS-A (aronia extract) composite film showed a significant color change at different pHs and potent antioxidant activity. At the same time, the PVA/CS-G (GSE) showed the highest antimicrobial activity against Escherichia coli (Gram-negative) and Listeria monocytogenes (Gram-positive) bacteria. The PVA/CS-CGA composite film, reinforced with CNCs/GSE/Aronia extract, showed the highest UV-barrier (95.5%), highest antioxidant activity (95%), potent antimicrobial activity, pH-sensitivity, lowest water vapor permeability (WVP), and desirable mechanical properties. The multifunctional properties of the produced composite films encourage their use as active and intelligent food packaging films to extend shelf life and monitor food quality.

Properties of Cellulose Pulp and Polyurethane Composite Films Fabricated with Curcumin by Using NMMO Ionic Liquid

Cellulose pulp (CP), polyurethane (PU), and curcumin-based biocompatible composite films were prepared using a simple cost-effective method. Significant structural and microstructural changes were studied using FT-IR spectroscopy, XRD, and SEM. The 5% and 10% gravimetric losses of the CP/PU/curcumin composite were found to be in the range 87.2–182.3 °C and 166.7–249.8 °C, respectively. All the composites exhibited single T_g values in the range 147.4–154.2 °C. The tensile strength of CP was measured to be 93.2 MPa, which dropped to 14.1 MPa for the 1:0.5 CP/PU composite and then steadily increased to 30.5 MPa with further addition of PU. The elongation at the break of the composites decreased from 8.1 to 3.7% with the addition of PU. The addition of PU also improved the water vapor permeability (3.96 × 10⁻⁹ to 1.75 × 10⁻⁹ g m⁻¹ s⁻¹ Pa⁻¹) and swelling ratio (285 to 202%) of the CP composite films. The CP/PU/curcumin composite exhibited good antioxidant activity and no cytotoxicity when tested on the HaCat cell line. The visual appearance and UV transmittance (86.2–32.9% at 600 nm) of the CP composite films were significantly altered by the incorporation of PU and curcumin. This study demonstrates that CP/PU/curcumin composites can be used for various packaging and biomedical applications.

Cubosomal Betamethasone-Salicylic Acid Nano Drug Delivery System for Enhanced Management of Scalp Psoriasis

Introduction

Betamethasone dipropionate (BD), a potent corticosteroid, and salicylic acid (SA), a keratolytic agent, have been used in combination to treat scalp psoriasis; however, undesirable side effects associated with their prolonged topical use are inevitable. In this study, BD and SA were loaded into cubosomes, a nanoparticulate system with outstanding biocompatibility, bio-adhesivity and penetration power.

Methods

Design of experiments (DOE) was utilized to prepare thirteen different cubosomal dispersions by emulsification technique using glycerol monoolein (GMO) as a lipid phase and Poloxamer 407 (P407) as a surfactant, sodium carboxymethyl cellulose (SCMC) was added to enhance the dispersions’ rheological properties. The thirteen dispersions were in-vitro characterized for their particle size, polydispersity index (PDI), zeta potential, BD and SA content and rheological behaviour. The desirability of an optimized formula (OF) was set to the smallest particle size, lowest zeta-potential and highest viscosity. The OF was in-vitro characterized for the same parameters in addition to transmission electron microscope imaging and in-vitro drug release. The OF’s anti-psoriatic activity was evaluated in-vivo using an imiquimod-induced psoriasis model.

Results

The OF achieved a particle size of 197.4 ± 9.47 nm, a PDI of 0.443 ± 0.025, a zeta potential of −44.4 ± 0.141mv, BD content of 105.85 ± 2.290%, SA content of 88.855 ± 2.920% with shear-thinning rheological behaviour and completed in-vitro drug release within 2–3 hours. The in-vivo studies confirmed the cubosomes’ higher anti-psoriatic efficacy over the commercial product with lower changes in ear thickness, spleen to body weight ratio, psoriasis area severity index score and improved histopathological findings.

Conclusion

The developed BD SA-loaded cubosomes exhibit promising anti-psoriatic activity attributed to its nano-size and unique lipid content, with enhanced skin penetration and modified rheological properties; increasing the formulation’s in-contact duration with the scalp resulting in lower application frequency and thus reduced BD and SA associated side effects.

Utilization of Waste Textile Cotton by Synthesizing Sodium Carboxymethyl Cellulose: An Approach to Minimize Textile Solid Waste

This research uses waste textile cotton (WTC) from the textile industry as a raw material to synthesize sodium carboxymethyl cellulose (CMC) by adapting a modified etherification methodology. Yields of technical CMC (TCMC), semipurified CMC (SPCMC), and purified CMC (PCMC) were $3.45\pm 0.17$  g, $2.49\pm 0.08$  g, and $1.51\pm 0.016$  g, respectively, per gram of cotton waste. Degree of substitution (DS) values of PCMC, SPCMC, and TCMC was $0.998\pm 0.007$ , $0.79\pm 0.031$ , and $0.561\pm 0.029$ , respectively. For PCMC, SPCMC, and TCMC, the purity of the prepared different grades of CMC was $98.59\pm 0.12$ %, $78.56\pm 1.93$ %, and $61.59\pm 2.31$ %, respectively. Fourier transform infrared spectroscopy (FTIR) peak values were 3437 cm-1, 1609 cm-1, and 1427 cm-1, proving WTC conversion to CMC. Furthermore, $2\theta$ values of X-ray diffraction (XRD) peaks were 9.7 and 20.5, confirming the transformation of WTC to CMC as well. Thermogravimetric analysis (TGA) and scanning electron microscope (SEM) have been assessed to define CMC’s thermal stability and morphology, respectively.

Multifunctional poly(vinyl alcohol) films using cellulose nanocrystals/oregano and cellulose nanocrystals/cinnamon Pickering emulsions: Effect of oil type and concentration

Poly (vinyl alcohol) (PVA) films with high transparency, UV-barrier, antioxidant, and antimicrobial properties were prepared using oregano essential oil (OEO) and cinnamon essential oil (CEO) Pickering emulsions. The effect of Pickering emulsion type and concentration on the PVA film properties was studied. Cellulose nanocrystals (CNCs) were used as a natural stabilizer to prepare OEO and CEO Pickering emulsions. Both emulsions showed spherical droplets with diameters of 155-291 nm, zeta potential of -36.2 to -49.6 mV, minimum inhibition concentration of 6.25-12.5 μL/mL, and inhibition zone of 40-65 mm, depending on oil type. Morphology and FTIR analysis showed that OEO and CEO Pickering emulsions were compatible with the PVA matrix. The UV-transmittance of PVA films decreased from 77.3% to 30.4% and 2.0% without sacrificing the transparency after adding OEO and CEO Pickering emulsions, respectively. Antimicrobial results showed that E. coli was more sensitive to CEO, while S. aureus was sensitive to OEO Pickering emulsion. PVA/CEO film displayed higher properties than PVA/OEO film.

Biobased composites from agro-industrial wastes and by-products

The greater awareness of non-renewable natural resources preservation needs has led to the development of more ecological high-performance polymeric materials with new functionalities. In this regard, biobased composites are considered interesting options, especially those obtained from agro-industrial wastes and by-products. These are low-cost raw materials derived from renewable sources, which are mostly biodegradable and would otherwise typically be discarded. In this review, recent and innovative academic studies on composites obtained from biopolymers, natural fillers and active agents, as well as green-synthesized nanoparticles are presented. An in-depth discussion of biobased composites structures, properties, manufacture, and life-cycle assessment (LCA) is provided along with a wide up-to-date overview of the most recent works in the field with appropriate references. Potential uses of biobased composites from agri-food residues such as active and intelligent food packaging, agricultural inputs, tissue engineering, among others are described, considering that the specific characteristics of these materials should match the proposed application.

A review of trends in the development of bionanocomposites from lignocellulosic and polyacids biomolecules as packing material making alternative: A bibliometric analysis

Contamination caused by the accumulation of petrochemical-based plastics has reached worrying magnitudes and led to the development of biopolymers as an option to mitigate the problem. This work thus presents a bibliometric analysis of all that concerns the development of such bionanocomposite materials, using ScientoPy and SciMAT software to establish associations between the number of published documents, countries, institutions and most relevant topics. The bionanocomposites topic was found to throw up the biggest number of documents associated (2008) with the different types of raw materials and methods used to obtain nanoparticles and their combination with biopolymeric materials, the result known as a "bionancomposite*". Analysis of the documents related to the application for development of packaging materials from biological molecules, carbohydrate polymers, compounds, conjugates, gels, glucans, hydrogels, membranes, mucilage (source unspecified), mucoadhesives, paper, polymers, polysaccharide, saccharides etc, is also presented, emphasizing mechanical, thermal and barrier properties, which, due to the inclusion of nanoparticles mainly from natural sources of cellulose, show increases of up to 30%. The inclusion of nanoparticles, especially those derived from cellulose sources, generally seeks to increase the properties of bionanocomposite materials. Regarding an increase in mechanical properties, specifically tensile strength, inclusions at percentages not exceeding 10 wt% can register increases that exceed 30% were reported.

Waste Materials as a Resource for Production of CMC Superabsorbent Hydrogel for Sustainable Agriculture

Waste materials are receiving more attention as concerns about the future of our planet increase. Cellulose is the most common substance in agricultural waste. Agricultural wastes containing cellulose are misplaced resources that could be reused in various fields for both environmental and economic benefits. In this work, 32 different kinds of waste are investigated for chemical modification in order to obtain carboxymethyl cellulose for the production of a superabsorbent hydrogel that can be applied in agriculture. A brief literature review is provided to help researchers wishing to obtain carboxymethyl cellulose by carboxymethylation starting with waste materials. We also provide details about methods to obtain as well as verify carboxymethylation. Carboxymethyl cellulose (CMC), as a constituent of cellulosic water and superabsorbent hydrogels with applications in agriculture, is described. Superabsorbent hydrogels with CMC are able to absorb huge amounts of water and are biodegradable.

Development of active packaging film from sodium alginate/carboxymethyl cellulose containing shallot waste extracts for anti-browning of fresh-cut produce

Owing to growing concerns about making pollution-free sustainable environment by reducing the dumping of agricultural waste and convert it into valuable product is a key to carry out the present study. The ultimate goal of this study is to convert onion solid wastes (OSWs) into active packaging and evaluating the anti-browning effect due to the OSWs holding rich polyphenols and antioxidants. The active packaging film was fabricated by using sodium alginate (SA) and carboxymethyl cellulose (CMC) along with SOWEs such as peel and stalk at 0.2% and 0.5% concentration. The film made with SA/CMC/SOWEs had good physical, mechanical, optical and barrier property, higher phenolic and antioxidant activity compared to control. In addition, the effect of SA/CMC/SOWEs film packaging on anti-browning and quality of fresh-cut apple and potato stored at 4 °C was studied. The results show the SA/CMC/SOWEs film had better effect on controlling browning index in fresh-cut apple and potato over the storage of 12 days and 5 days. This study concludes that the SA/CMC film developed with shallot stalk extract can be used for wrapping of fresh-cut fruits and vegetables. It also prevents browning and maintains the overall quality than control and shallot peel incorporated film.

Super-hydrophobic Cellulose Nanofiber Air Filter with Highly Efficient Filtration and Humidity Resistance

High-air humidity, especially condensation into droplets under the influence of temperature, can pose a serious threat to air purification filters. This report introduces the use of methyltrimethoxysilane (MTMS) for the silanization hydrophobic modification of cellulose nanofibers (CNFs) and obtains an air filter with super-hydrophobicity (CA = 152.4°) and high-efficiency filtration of particulate matter (PM) through the freeze-drying technology. The antihumidity performance of CNFs filters that undergo hydrophobic modification in high-humidity air is improved. Especially in the case of high-humidity air forming condensed water droplets, the increase in the rate of filtration resistance of the hydrophobically modified CNFs filter is much lower than that of the unmodified filter. In addition, the water-vapor-transmission rate of the hydrophobically modified filter is improved. More importantly, adding MTMS can regulate the porous structure of CNFs filters and improve the filtration performance. The specific surface area and the porosity of the filter are 26.54 m²/g and 99.21%, respectively, and the filtering effects of PM_1.0 and PM_2.5 reach 99.31 and 99.75%, respectively, while a low-filtration resistance (42 Pa) and a quality factor of up to 0.122 Pa^-1 are achieved. This work has improved the application potential of high-performance air-purification devices to remove particulate pollution and may provide useful insights to design next-generation air filters suitable for application in high-air humidity.

Electrical stimulation of neonatal rat cardiomyocytes using conductive polydopamine-reduced graphene oxide-hybrid hydrogels for constructing cardiac microtissues

The development of diversified biomaterials in tissue engineering has been promoted by growing research into carbon-based nanomaterials. Usually, ideal scaffold materials should possess properties similar to the extracellular matrix of natural myocardial tissue. In this study, dopamine-reduced graphene oxide (GO), was prepared and doped into gelatin methacrylate (GelMA) hydrogels, resulting in novel conductive and mechanical properties for controlling cell growth. Cardiomyocytes (CMs) cultured on PDA-rGO-incorporated hydrogels (GelMA-PDA-rGO) had greater cytocompatibility than those cultured on GelMA hydrogels, as evidenced by higher cell survival rates and up-regulation of cardiac-relevant proteins. Finally, electrical stimulation was applied to facilitate the maturation of CMs which was seeded on different hydrogels. The findings revealed that electrical stimulation of conductive hybrid hydrogel scaffolds improved the orientational order parameter of sarcomeres (OOP). In addition, propagation of intercellular pacing signals, which improves the expression of gap junction proteins was noticed, likewise calcium handling capacity was present in conductive hybrid hydrogels compared to those in pure GelMA group. This study has shown that the combination of GelMA-PDA-rGO based conductive hydrogels and electrical stimulation possessed synergistic effects for engineering a more functional and mature myocardium layer as well as further application in drug screening and disease modeling in vitro.