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This study demonstrates the successful synthesis of Ni/Y[sub.2]O[sub.3] nanocomposite particles through the application of ultrasound-assisted precipitation using the ultrasonic spray pyrolysis technique. They were collected in a water suspension with polyvinylpyrrolidone (PVP) as the stabiliser. The presence of the Y[sub.2]O[sub.3] core and Ni shell was confirmed with transmission electron microscopy (TEM) and with electron diffraction. The TEM observations revealed the formation of round particles with an average diameter of 466 nm, while the lattice parameter on the Ni particle’s surface was measured to be 0.343 nm. The Ni/Y[sub.2]O[sub.3] nanocomposite particle suspensions were lyophilized, to obtain a dried material that was suitable for embedding into a polylactic acid (PLA) matrix. The resulting PLA/Ni/Y[sub.2]O[sub.3] composite material was extruded, and the injection was moulded successfully. Flexural testing of PLA/Ni/Y[sub.2]O[sub.3] showed a slight average decrease (8.55%) in flexural strength and a small decrease from 3.7 to 3.3% strain at the break, when compared to the base PLA. These findings demonstrate the potential for utilising Ni/Y[sub.2]O[sub.3] nanocomposite particles in injection moulding applications and warrant further exploration of their properties and new applications in various fields.

The present work analyzes the influence of modified, epoxidized and maleinized corn oil as a plasticizing and/or compatibilizing agent in the PLA–PHB blend (75% PLA and 25% PHB wt.%). The chemical modification processes of corn oil were successfully carried out and different quantities were used, between 0 and 10% wt.%. The different blends obtained were characterized by thermal, mechanical, morphological, and disintegration tests under composting conditions. It was observed that to achieve the same plasticizing effect, less maleinized corn oil (MCO) is needed than epoxidized corn oil (ECO). Both oils improve the ductile properties of the PLA–PHB blend, such as elongation at break and impact absorb energy, however, the strength properties decrease. The ones that show the highest ductility values are those that contain 10% ECO and 5% MCO, improving the elongation of the break of the PLA–PHB blend by more than 400% and by more than 800% for the sample PLA.

Alginate, a promising biopolymer in the food, biomedical, pharmaceutical, and electronic materials industries, is characterized by its biodegradability, biocompatibility, low toxicity, and gel-forming properties. It is most abundantly found in brown algae. However, conventional dilute acid and alkali extraction methods face limitations in commercialization due to their long processing time, low throughput, and high solvent requirements. In this study, a microwave-assisted extraction (MAE) process for sodium alginate was designed to improve extraction efficiency. The solid/liquid ratio, extraction temperature, and extraction solvent concentration were major variables affecting sodium alginate extraction from Undaria pinnatifida (sea mustard). They were then statistically optimized using response surface methodology. Under optimal conditions (13.27 g/L, 91.86 °C, 2.51% (w/v), and 15 min), the yield was 38.41%, which was 93.43% of the theoretical content of sodium alginate in Undaria pinnatifida. Our work has confirmed the productivity and industrial feasibility of the efficient extraction of sodium alginate from marine biomass, and we hope that it will serve as an encouraging case for the application of biopolymers as one of the desirable options for alternative petrochemicals to construct a sustainable society.

Transient Robotics As described by Fabian Wiesemüller, Mirko Kovač, and colleagues in article number 2300037, transient robots are biodegradable tools for assessing environmental health and autonomously creating ecological models. After collecting the targeted environmental data, the aerial robot lands and completes its service life. The structure of the robot, made from renewable biopolymers, degrades and the stored nutrients are reintroduced into the carbon cycle. This circular economy approach towards robot manufacturing minimizes the environmental footprint.

In this work, FeSiAl-Fe.sub.3O.sub.4-GR/PLA composite printed wires were prepared by a two-step process of ball-mill mixing and melt extrusion using polylactic acid (PLA) as the base material, graphene (GR), FeSiAl and Fe.sub.3O.sub.4 as microwave absorbing enhancers. The results show that when the mass percentages of FeSiAl and Fe.sub.3O.sub.4 are 15 wt% and 15 wt% and the thickness is 5.3 mm, the composite material obtains the largest finite absorption bandwidth, at which time, the minimum reflection loss is - 48.08 dB and the absorption bandwidth is 3.52 GHz. When the mass percentages of FeSiAl and Fe.sub.3O.sub.4 are 20 wt% and 10 wt% and the thickness is 5.7 mm, the composite material has the strongest reflection loss, and the minimum reflection loss is - 50.62 dB and the absorption bandwidth is 3.28 GHz. Effective absorption of S, C, X and Ku band microwaves can be achieved by adjusting the thickness of the composite material. The excellent microwave absorption performance of the composites is mainly attributed to the effective synergy of the dual magnetic media, which enhances the absorption effects of interfacial polarization, dipole polarization, natural resonance, eddy current loss, and multiple reflections. Our research provides an effective way to prepare lightweight and efficient microwave absorbing materials in a green and simple process.

Packaging is an integral part of food products, allowing the preservation of their quality. It plays an important role, protecting the packed product from external conditions, maintaining food quality, and improving properties of the packaged food during storage. Nevertheless, commonly used packaging based on synthetic non-biodegradable polymers causes serious environmental pollution. Consequently, numerous recent studies have focused on the development of biodegradable packaging materials based on biopolymers. In addition, biopolymers may be classified as active packaging materials, since they have the ability to carry different active substances. This review presents the latest updates on the use of silver nanoparticles in packaging materials based on biopolymers. Silver nanoparticles have become an interesting component of biodegradable biopolymers, mainly due to their antimicrobial properties that allow the development of active food packaging materials to prolong the shelf life of food products. Furthermore, incorporation of silver nanoparticles into biopolymers may lead to the development of materials with improved physical-mechanical properties.

Key Points Formation of the biofilm matrix induces a unique environment for bacteria that allows the dynamic biofilm mode of life. Biofilms, and the resulting lifestyle, are built in specific, defined steps, producing a bacterial community that is heterogeneous in space and time. Extracellular polymeric substances (EPS) immobilize biofilm cells, keeping them in long-term close proximity and, thus, allowing intense interactions to occur, including cell–cell communication, horizontal gene transfer and the formation of synergistic microconsortia. Owing to the retention of extracellular enzymes in the matrix, a versatile external digestive system is generated: dissolved and particulate nutrients imported through the water phase of the matrix can be sequestered, accumulated and utilized. The matrix acts as an ultimate recycling yard, keeping all the components of lysed cells available, including DNA, and possibly therefore serving as a large genetic archive. Gradient formation creates a wide range of very different habitats, contributing to biodiversity in biofilms. The matrix protects organisms in the biofilm from desiccation, biocides, antibiotics, heavy metals, ultraviolet radiation, host immune defences and many protozoan grazers. Eventually, EPS can serve as a nutrient source, but — as for many other structural polymers in biology — some EPS components are only slowly biodegradable. The vast variety of EPS components means that their complete degradation requires a wide range of enzymes. Ecologically, competition and cooperation in the confined space of the EPS matrix, and competition for the limited nutrients in particular, lead to constant adaptation of population fitness. Most bacteria live in biofilms, the structure of which depends on the biofilm matrix. This matrix is composed of extracellular polymeric substances, which are compounds that are produced by the bacteria. Here, Flemming and Wingender describe the properties of the matrix and provide an overview of the individual matrix components. The microorganisms in biofilms live in a self-produced matrix of hydrated extracellular polymeric substances (EPS) that form their immediate environment. EPS are mainly polysaccharides, proteins, nucleic acids and lipids; they provide the mechanical stability of biofilms, mediate their adhesion to surfaces and form a cohesive, three-dimensional polymer network that interconnects and transiently immobilizes biofilm cells. In addition, the biofilm matrix acts as an external digestive system by keeping extracellular enzymes close to the cells, enabling them to metabolize dissolved, colloidal and solid biopolymers. Here we describe the functions, properties and constituents of the EPS matrix that make biofilms the most successful forms of life on earth.

During the last decades, biopolymers experienced a renaissance. The increasing limitation of fossil resources in combination with a public demand for environmental-friendly and sustainable processes has led to the formation of a market for biobased plastics. Especially non-biodegradable bioplastics are very interesting materials, as they combine the benefits of reduced carbon footprint during production and increased resource efficiency with the persistence to microbial degradation. Consequently, persistent biomass-derived plastic materials are highly promising to substitute conventional fossil-based plastics in applications, which require durability and longevity. Non-biodegradable bioplastics derived from renewable resources represent 57% of all bioplastics with partially biobased polyethylene terephthalate currently leading the market, followed by biobased polyamides and fully biomass-derived polyethylene. An exceptional biopolymer with thermoplastic properties was discovered only two decades ago, when—for the first time—polythioesters were synthesized by microbial fermentation. Though synthesized by bacteria, it turned out that polythioesters are non-biodegradable by microorganisms in contrast to all other biopolymers and thus, represent a novel non-biodegradable bioplastic material. This review gives an overview about the recent development and progress regarding bioplastics with special focus on persistent bioplastics. We describe the generation of the respective monomers from biomass-derived substrates and summarize the current status of production, which range from the laboratory-scale up to large-scale industrial processes.

Pickering emulsions stabilized by food-grade colloidal particles have attracted increasing attention in recent years due to their \"surfactant-free\" nature. In this study, the alkali-treated zein (AZ) was prepared via restricted alkali deamidation and then combined with sodium alginate (SA) in different ratios to obtain AZ/SA composite particles (ZS), which were used to stabilize Pickering emulsion. The degree of deamidation (DD) and degree of hydrolysis (DH) of AZ were 12.74% and 6.58% respectively, indicating the deamidation occurred mainly in glutamine on the side chain of the protein. After the treatment with alkali, AZ particle size decreased significantly. Moreover, the particle size of ZS with different ratios was all less than 80 nm. when the AZ/SA ratio was 2:1(Z2S1) and 3:1(Z3S1), the three-phase contact angle (θ[sub.o/w]) were close to 90°, which was favorable for stabilizing the Pickering emulsion. Furthermore, at a high oil phase fraction (75%), Z3S1-stabilized Pickering emulsions showed the best long-term storage stability within 60 days. Confocal laser scanning microscope (CLSM) observations showed that the water-oil interface was wrapped by a dense layer of Z3S1 particles with non-agglomeration between independent oil droplets. At constant particle concentration, the apparent viscosity of the Pickering emulsions stabilized by Z3S1 gradually decreased with increasing oil phase fraction, and the oil-droplet size and the Turbiscan stability index (TSI) also gradually decreased, exhibiting solid-like behavior. This study provides new ideas for the fabrication of food-grade Pickering emulsions and will extend the future applications of zein-based Pickering emulsions as bioactive ingredient delivery systems.