Search

Biodegradable and nontoxic chitosan edible coatings offer a promising alternative to conventional plastic food packaging materials. Recently, there has been significant interest in incorporating green plasticizers into these coatings. Accordingly, response surface methodology was employed to optimize a chitosan coating formulation that integrates Aloe vera extracts and a deep eutectic solvent (choline chloride–citric acid) as a plasticizer. The selection of the optimized formulation was related to quality characteristics of coated blackberries including their weight loss, pH, total phenolic content, total anthocyanin content, and antioxidant activity after 7 days of cold storage. The models demonstrated a high level of significance between the responses and independent variables, with p value less than 0.0001. The optimal coating formulation for blackberry fruits was identified as 2.05% (v/v) aloe rind extract, 1.1% (w/w) aloe gel extract, and 15% (w/w) choline chloride–citric acid. The developed film was characterized by ATR‐FTIR and SEM for its intermolecular interactions and surface morphology, respectively, demonstrating good combability of polymer matrix with the plasticizer and aloe extracts. The optimized film was compared to a pure chitosan film in regard to their physical and mechanical properties. The alternative plasticizer choline chloride–citric acid improved the flexibility of the edible packaging by enhancing its mechanical properties, such as tensile strength, elongation at rupture, and elastic modulus. Additionally, the incorporation of this plasticizer and plant extracts slightly increased the transparency of the film. The coating was then applied to blackberry fruits in order to investigate the potential of the developed coating formulation to maximize the shelf life of food products. The results indicated the ability of the coating to extend shelf life and maintain the quality of the fruits. [ABSTRACT FROM AUTHOR]

Poly(3-hexylthiophene-2,5-diyl) (P3HT)-based semiconducting electrospun nanocomposite fibrous emitters were successfully fabricated by combining P3HT with poly(ethylene oxide) (PEO) and commercially available CsPbBr3 perovskite quantum dots (PQDs). The latter were employed as a synergistic photoluminescence emitter of high efficiency within the P3HT/PEO blended polymer matrix, while PEO was used as an auxiliary polymer to assist the electrospinnability of P3HT. The produced materials were characterized with respect to their chemical composition and morphology by scanning electron microscopy (SEM) and transmission electron microscopy/energy-dispersive x-ray analysis (TEM/EDX) whereas fluorescence microscopy and spectroscopy were employed to study their optical properties. Based on the obtained results, it was confirmed that the PQDs were successfully encapsulated within the electrospun fibers at a high percentage (10 wt.%), retaining at the same time their optical properties and nanoscale dimensions. Moreover, the experimental data obtained suggested the existence of inter-material interactions between P3HT and PQDs. Consequently, this study creates new pathways in the development of innovative fibrous nanocomposites with unique optoelectronic features, rendering them highly interesting in light-harvesting, sensing and optoelectronic applications. [ABSTRACT FROM AUTHOR]

The present work reports on the synthesis and characterization of iridium (Ir)-based nanohybrids with variable chemical compositions. More specifically, highly stable polyvinylpyrrolidone (PVP) nanohybrids of the PVP-IrO2 and PVP-Ir/IrO2 types, as well as non-coated Ir/IrO2 nanoparticles, are synthesized using different synthetic protocols and characterized in terms of their chemical composition and morphology via X-ray photoelectron spectroscopy (XPS) and scanning transmission electron microscopy (STEM), respectively. Furthermore, their nonlinear optical (NLO) response and optical limiting (OL) efficiency are studied by means of the Z-scan technique, employing 4 ns laser pulses at 532 and 1064 nm. The results demonstrate that the PVP-Ir/IrO2 and Ir/IrO2 systems exhibit exceptional OL performance, while PVP-IrO2 presents very strong saturable absorption (SA) behavior, indicating that the present Ir-based nanohybrids could be strong competitors to other nanostructured materials for photonic and optoelectronic applications. In addition, the findings denote that the variation in the content of IrO2 nanoparticles by using different synthetic pathways significantly affects the NLO response of the studied Ir-based nanohybrids, suggesting that the choice of the appropriate synthetic method could lead to tailor-made NLO properties for specific applications in photonics and optoelectronics. [ABSTRACT FROM AUTHOR]

The lifecycle of a material and the environmental trace is becoming a dominant parameter on material's selection process. The present study focuses on the fabrication and thermomechanical characterization of fully recycled composite materials based on high‐density polyethylene (HDPE) reinforced with bio‐natural inclusions of carbonized Luffa cylindrica (c‐LC). Materials fabrication was realized by applying the twin roll mill process, which enabled the production of a series of polymer composites with variable c‐LC content. The morphological and thermomechanical characteristics were investigated by means of scanning electron microscopy and dynamic mechanical analysis, respectively. Morphological results indicate a reinforcing geometry of the inclusions, while the thermomechanical characterization verifies the reinforcement of HDPE thermoplastic with the biochar inclusions thus paving the way to the use of such fully‐recycled biochar thermoplastic composite materials on structural and semi‐structural applications. [ABSTRACT FROM AUTHOR]