Rational design of active packaging films based on polyaniline-coated polymethyl methacrylate/nanocellulose composites

Nanocellulose-stabilized nanocomposites for effective Hg(II) removal and detection: a comprehensive review

Mercury pollution, with India ranked as the world's second-largest emitter, poses a critical environmental and public health challenge and underscores the need for rigorous research and effective mitigation strategies. Nanocellulose is derived from cellulose, the most abundant natural polymer on earth, and stands out as an excellent choice for mercury ion remediation due to its remarkable adsorption capacity, which is attributed to its high specific surface area and abundant functional groups, enabling efficient Hg(II) ion removal from contaminated water sources. This review paper investigates the compelling potential of nanocellulose as a scavenging tool for Hg(II) ion contamination. The comprehensive examination encompasses the fundamental attributes of nanocellulose, its diverse fabrication techniques, and the innovative development methods of nanocellulose-based nanocomposites. The paper further delves into the mechanisms that underlie Hg removal using nanocellulose, as well as the integration of nanocellulose in Hg detection methodologies, and also acknowledges the substantial challenges that lie ahead. This review aims to pave the way for sustainable solutions in mitigating Hg contamination using nanocellulose-based nanocomposites to address the global context of this environmental concern.

Sustainable cellulose-based multifunctional material for electromagnetic shielding, flame retardancy and antibacterial

Biomass-based multifunctional electromagnetic shielding materials have attracted extensive interest in academia and industry due to the sustainability of biomass and the environmental adaptability of multifunctional materials. After removing lignin and hemicellulose wood become a porous substrate with aligned cellulose, which is a good platform for building cellulose-based materials. In this work, a cellulose composite with sandwich-like structure was constructed by in-situ polymerization of aniline on delignified wood and coating a PDMS/CNT layer. Benefiting from the natural porous hierarchical structure and the constructed multilayer continuous conductive network, the PDMS/CNT/PANI WA exhibits excellent electrical conductivity (18.6 S/m) and electromagnetic shielding performance (shielding efficiency value of 26 dB at the X band (8.2-12.4 GHz)). The synergistic effect of PANI and CNT endowed the material with excellent flame retardancy (HRR, THR and HRC decreased by 84 %, 53.4 % and 83.3 %) and significant antibacterial activity. Moreover, PDMS imparts a water contact angle of 105° to the material, which acts as a protective layer, further improves the durability of the material. This work provides a new strategy for developing sustainable and multifunctional electromagnetic shielding materials.

Emerging Applications of Versatile Polyaniline-Based Polymers in the Food Industry

Intrinsically conducting polymers (ICPs) have been widely studied in various applications, such as sensors, tissue engineering, drug delivery, and semiconductors. Specifically, polyaniline (PANI) stands out in food industry applications due to its advantageous reversible redox properties, electrical conductivity, and simple modification. The rising concerns about food safety and security have encouraged the development of PANI as an antioxidant, antimicrobial agent, food freshness indicator, and electronic nose. At the same time, it plays an important role in food safety control to ensure the quality of food. This study reviews the emerging applications of PANI in the food industry. It has been found that the versatile applications of PANI allow the advancement of modern active and intelligent food packaging and better food quality monitoring systems.

Synthesis of a new hydrophobic coating film from stearic acid of buffalo fat

This experiment involved the chemical conversion of pure stearic acid from buffalo adipose tissue to a waxy stearyl stearate, which was subsequently applied as a coating film to extend the shelf life of recently harvested fruits. Fat was extracted from minced adipose tissue using the dry rendering procedure, and it was then characterized. The extracted fat was hydrolyzed into a mixture of free fatty acids and glycerol. The supercritical CO₂ extractor was used for stearic acid individual extraction in pure form from the free fatty acid mixture, and it was confirmed according to its melting point (69.2-70.0 °C), elemental analysis, GC-MS for esterified fatty acids. The isolated stearic acid was used for the synthesis of a new hydrophobic wax named stearyl stearate. The chemical structure of the prepared compound was established according to its elemental analysis and spectral data. The new hydrophobic wax was used as a coating film to enhance the shelf life of freshly harvested tomato fruits. Therefore, stearyl stearate solution (2.00% w/v diethyl ether) was used for tomato coating and compared to chitosan-coated tomatoes, where weight loss, pH, fruit firmness, ascorbic acid concentration, and total soluble solids were studied for a period of 15 days at 23 ± 1.0 °C and 65 ± 2.0% relative humidity. The results revealed that coating with stearyl stearate solution (2.00% w/v diethyl ether) could delay tomatoes' ripening during the experiment condition. A sensory evaluation of the coated tomatoes was carried out and showed acceptable taste for the tomatoes that were coated with stearyl stearate. On the other hand, the acute oral toxicity of stearyl stearate using albino mice showed complete safety up to 25 g/kg mice weight.

Source of Nanocellulose and Its Application in Nanocomposite Packaging Material: A Review

Food packaging nowadays is not only essential to preserve food from being contaminated and damaged, but also to comply with science develop and technology advances. New functional packaging materials with degradable features will become a hot spot in the future. By far, plastic is the most common packaging material, but plastic waste has caused immeasurable damage to the environment. Cellulose known as a kind of material with large output, wide range sources, and biodegradable features has gotten more and more attention. Cellulose-based materials possess better degradability compared with traditional packaging materials. With such advantages above, cellulose was gradually introduced into packaging field. It is vital to make packaging materials achieve protection, storage, transportation, market, and other functions in the circulation process. In addition, it satisfied the practical value such as convenient sale and environmental protection, reduced cost and maximized sales profit. This review introduces the cellulose resource and its application in composite packaging materials, antibacterial active packaging materials, and intelligent packaging materials. Subsequently, sustainable packaging and its improvement for packaging applications were introduced. Finally, the future challenges and possible solution were provided for future development of cellulose-based composite packaging materials.

Biocidal activity of curcumin and cationic polymer possessing composites

There is a growing interest in new type of biocidal compounds with antibacterial properties against bacteria. In this study, new antibacterial synthetic materials bearing curcumin and cationic polymers were synthesized. In the synthesis stage, the methacrylate functional cationic monomer was synthesized via the Michael addition route by using 3-acryloxy-2-hydroxypropyl methacrylate and 3-amino pyridine to obtain Monomer 1. Monomer 1 was further quaternized with hexyl bromide to obtain a cationic methacrylate functional monomer. Free-radical polymerization of Monomer 1 and methyl acrylate was conducted in the presence of azobisisobutyronitrile under dimethylformamide solvent. The composite formulation was conducted by using turmeric extract Curcuma longa (curcumin), hydroxyapatite, montmorillonite, and silver nitrate. The materials were analyzed by using the methods of X-ray diffraction, nuclear magnetic resonance, Fourier transform infrared spectroscopy, and scanning electron microscopy. The biocidal activities against the bacteria Escherichia coli, Listeria monocytogenes, Salmonella, and Staphylococcus aureus were analyzed using agar well diffusion method. From the Fourier transform infrared, X-ray diffraction, and scanning electron microscopy analysis results of the synthesized nanocomposites, it is seen that they form strong connections with the components added to the composites and form an exfoliated structure. According to the antibacterial analysis results, the nanocomposites obtained have showed a strong antibacterial resistance against E.coli, L.monocytogenes, Salmonella, and S. aureus bacteria, and the high inhibition zone areas were obtained.