This study demonstrates the successful synthesis of Ni/Ysub.2Osub.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 Ysub.2Osub.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/Ysub.2Osub.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/Ysub.2Osub.3 composite material was extruded, and the injection was moulded successfully. Flexural testing of PLA/Ni/Ysub.2Osub.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/Ysub.2Osub.3 nanocomposite particles in injection moulding applications and warrant further exploration of their properties and new applications in various fields.
Biocomposites were fabricated utilizing polylactic acid (PLA) combined with native starch sourced from mountain’s yam (Dioscorea remotiflora Knuth), an underexplored tuber variety. Different starch ...compositions (7.5, 15.0, 22.5, and 30.0 wt.%) were blended with PLA in a batch mixer at 160 °C to produce PLA/starch biocomposites. The biocomposites were characterized by analyzing their morphology, particle size distribution, thermal, X-ray diffraction (XDR), mechanical, and dynamic mechanical (DMA) properties, water absorption behavior, and color. The results showed that the amylose content of Dioscorea remotiflora starch was 48.43 ± 1.4%, which corresponds to a high-amylose starch (>30% of amylose). Particle size analysis showed large z-average particle diameters (Dz0) of the starch granules (30.59 ± 3.44 μm). Scanning electron microscopy (SEM) images showed oval-shaped granules evenly distributed throughout the structure of the biocomposite, without observable agglomeration or damage to its structure. XDR and DMA analyses revealed an increase in the crystallinity of the biocomposites as the proportion of the starch increased. The tensile modulus (E) underwent a reduction, whereas the flexural modulus (Esub.flex) increased with the amount of starch incorporated. The biocomposites with the highest Esub.flex were those with a starch content of 22.5 wt.%, which increased by 8.7% compared to the neat PLA. The water absorption of the biocomposites demonstrated a higher uptake capacity as the starch content increased. The rate of water absorption in the biocomposites followed the principles of Fick’s Law. The novelty of this work lies in its offering an alternative for the use of high-amylose mountain’s yam starch to produce low-cost bioplastics for different applications.
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.
Trends in biopolymer science applied to cosmetics Mendoza‐Muñoz, Néstor; Leyva‐Gómez, Gerardo; Piñón‐Segundo, Elizabeth ...
International journal of cosmetic science,
December 2023, Letnik:
45, Številka:
6
Journal Article
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The term biopolymer refers to materials obtained by chemically modifying natural biological substances or producing them through biotechnological processes. They are biodegradable, biocompatible and ...non‐toxic. Due to these advantages, biopolymers have wide applications in conventional cosmetics and new trends and have emerged as essential ingredients that function as rheological modifiers, emulsifiers, film‐formers, moisturizers, hydrators, antimicrobials and, more recently, materials with metabolic activity on skin. Developing approaches that exploit these features is a challenge for formulating skin, hair and oral care products and dermatological formulations. This article presents an overview of the use of the principal biopolymers used in cosmetic formulations and describes their sources, recently derived structures, novel applications and safety aspects of the use of these molecules.
Résumé
Le terme biopolymère fait référence aux matériaux obtenus par modification chimique des substances biologiques naturelles ou ceux qui surviennent des processus biotechnologiques. Ils sont biodégradables, biocompatibles, et non‐toxiques. Du à leur avantages, les biopolymères ont de larges applications dans les cosmétiques conventionnels ainsi que dans les nouvelles tendances, et se placent comme des ingrédients essentiels qui peut être utilise comme modificateurs rhéologiques, émulsifiants, producteurs de films, humectants, hydratants, antimicrobiens, et, plus récemment, comme matériaux avec activité métabolique sur la peau. Le développement d'approches compte tenu de ces caractéristiques constitue un défi pour la création de produits de soins capillaires, dermatologiques et buccodentaires. Cet article présente une vision sur l'utilisation des principaux biopolymères dans les produits cosmétiques, et décrit leurs sources, leur structures dérivées, les nouvelles applications, ainsi que les aspects de sécurité lies à leur utilisation comme molécules cosmétiques.
Abbreviated : Biopolymers offer a wide range of advantages that, properly applied, can have a huge impact on new cosmetic trends. This review focuses on polysaccharide‐ and protein‐based biopolymers, describing sources of obtention, newly derived molecules, trends in cosmetic products and safety aspects.
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.
Bacterial polyhydroxyalkanoates: Still fabulous? Możejko-Ciesielska, Justyna; Kiewisz, Robert
Microbiological research,
November 2016, 2016-Nov, 2016-11-00, 20161101, Letnik:
192
Journal Article
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Bacterial polyhydroxyalkanoates (PHA) are polyesters accumulated as carbon and energy storage materials under limited growth conditions in the presence of excess carbon sources. They have been ...developed as biomaterials with unique properties for the past many years being considered as a potential substitute for conventional non-degradable plastics. Due to the increasing concern towards global climate change, depleting petroleum resource and problems with an utilization of a growing number of synthetic plastics, PHAs have gained much more attention from industry and research. These environmentally friendly microbial polymers have great potential in biomedical, agricultural, and industrial applications. However, their production on a large scale is still limited. This paper describes the backgrounds of PHAs and discussed the current state of knowledge on the polyhydroxyalkanoates. Ability of bacteria to convert different carbon sources to PHAs, the opportunities and challenges of their introduction to global market as valuable renewable products have been also discussed.
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.
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 (θsub.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.
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