Improved performance of metal-organic frameworks loaded cellulose acetate based film for packaging application

Full life cycle green preparation of collagen-based food packaging films using Halocynthia roretzi as raw material

The extraction of collagen for packaging films typically requires a time-consuming process and the use of substantial chemicals. Herein, we present a full life cycle green preparation method for rapidly producing collagen-based food packaging films using Halocynthia roretzi (HR), a collagen-rich marine organism, as raw material. We first prepared the micro/nano-sized collagen fibers from HR tissue by utilizing urea and sonication as effective hydrogen-bond breakers. Subsequently, the collagen fiber was rapidly fabricated into a film through vacuum filtration. The resulting collagen fiber film (CFF) exhibited a uniform and dense surface, along with good tensile properties, water resistance, and biodegradability. In addition, the deposition of chitosan (CS) on the surface of CFF resulted in a remarkable preservation effect for both strawberries and pork. This full life cycle preparation method for collagen-based films provides a promising and innovative approach to the sustainable preparation of food packaging films.

Derivation of porous cellulose propionate using hydrated hydroxyl groups and hydraulic pressure

This study aimed to enhance the thermal stability of microporous separators by introducing cellulose propionate (CP) as an innovative polymer matrix material, supplemented with glycerin as an additive. CP/glycerin composite membranes were created using hydraulic pressure techniques to reinforce essential separator properties. SEM analysis unveiled interconnected pores crucial for efficient ion transport, initiating water flux measurements at 5 bar. These measurements showcased improved mechanical strength, resulting in a porosity of 74.1 %. FT-IR spectroscopy illustrated CP-glycerin interactions, inducing plasticization and facilitating pore formation. Thermal Gravimetric Analysis (TGA) demonstrated superior thermal stability in CP/glycerin composite membranes compared to cellulose acetate (CA). Differential Scanning Calorimetry (DSC) revealed a slight reduction in thermal stability within a specific temperature range due to glycerin-induced plasticization effects. Nonetheless, the melting temperature (Tm) of CP/glycerin membranes increased to 188.4 °C, indicating heightened stability at elevated temperatures. Despite pressure-induced pore formation, CP/glycerin membranes exhibited enhanced thermal stability, suggesting reinforced molecular interactions. Overall, this study introduces a novel CP/glycerin composite membrane featuring improved thermal stability, enhanced strength, and controlled pore structures essential for efficient lithium-ion battery applications.

Exploring sustainable food packaging: Nanocellulose composite films with enhanced mechanical strength, antibacterial performance, and biodegradability

Food packaging films play a vital role in preserving and protecting food. However, due to their non-biodegradability, conventional packaging materials have led to significant environmental pollution. To overcome this hurdle, we have developed safe, innovative, sustainable and biodegradable packaging materials that can effectively extend the shelf life of food. In this study, two types of cellulose materials cellulose nanofibers (CNF) and carboxymethyl cellulose (CMC) with complementary roles were combined to prepare nanocellulose composite films with high transparency (90.3 %) of a certain thickness (30 ± 0.019 μm) by solution casting method, and their mechanical properties were further optimized by the addition of plasticizer-glycerol (Gly) and cross-linking agent-glutaraldehyde (GA), so as to maintain the strong tensile strength (≈112.60 MPa) and better malleability (4.12 %). In addition, we loaded the natural active agent tea polyphenols (TPs) with different concentrations to study the inhibition effect on E.coli and S.aureus and to simulate food packaging. Finally, we also found that the synthesized nanocellulose composite films can also achieve rapid degradation in a short time through soil burial, water flushing and immersion. The excellent performance demonstrated in this study provides reference value for further replacing petroleum-based materials with biomass materials in the field of food packaging.

Fabrication of UiO-66/GCN, a Hybrid Photocatalyst, for Effective Degradation of Ciprofloxacin, Toxicity Estimation, and Its Antibacterial Activity

Fabrication of a metal-organic framework-based photocatalyst has been gaining much interest due to its higher surface area and reasonable band gap, enhancing its photocatalytic activity. This study attempted a facile synthesis of the hybrid photocatalyst UiO-66 doped with graphitic carbon nitride (GCN) by a simple solvothermal method. This composite minimized the drawback related to photogenerated charge transfer and recombination and helped the absorption of visible light. The material was investigated by using various instrumental techniques. In this work, ciprofloxacin (CIP), a fluoroquinolone drug, was chosen as a target micropollutant, and a photodegradation experiment was carried out by using UiO-66, GCN, and UiO-66/GCN under a visible light source, which exhibited 81.85, 69.48, and 93.60% of degradation, respectively. Finally, liquid chromatography mass spectrometry analysis and theoretical computation were carried out to identify the CIP degradation mechanism, and T.E.S.T. software was used to investigate the toxicity of the intermediate products. Apart from photocatalytic activity, the prepared material was also tested for its antibacterial properties against Staphylococcus aureus and Escherichia coli.

Multifunctional food packaging materials: Lactoferrin loaded Cr-MOF in films-based gelatin/κ-carrageenan for food packaging applications

In this study, antimicrobial biocomposite films based on gelatin-κ-carrageenan (Gκ) with 1, 2 and 4 % lactoferrin (L) loaded chromium-based metal-organic frameworks (L@Cr-MOFs) nanoparticles were synthesized by casting methods. The addition of L loaded Cr-MOFs into Gκ based films increased elongation at break from 2.19 to 14.92 % and decreased the tensile strength from 65.1 to 31.22 MPa. L@Cr-MOFs addition reduced swelling index (from 105 to 70.8 %), water solubility (from 61.3 to 34.63 %) and water vapor permeability (from 2.46 to 2.19 × 10-11 g. m/m2. s). When the additional amount was 4 wt%, the Gκ/L@Cr-MOFs films showed antibacterial effects against Escherichia coli and Staphylococcus aureus with the inhibition zone of 19.7 mm and 20.2 mm, respectively. In addition, strawberries preservation trial shown that the Gκ/L@Cr-MOFs films delayed the growth of spoilage molds on the surface of fruits. This research indicated that Gκ/L@Cr-MOFs are promising active packaging materials for the preservation of perishable fruits.