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Topic Review
Silicones Renewed for Emerging Applications
Polydimethylsiloxane (PDMS) is the basis of the vast majority of silicone products that have found use in almost all areas of human activity, from cosmetics to the nuclear or aerospace industry. After 80 years from the first direct synthesis of silicones (2020), they still enjoy great interest, both scientific and applicative, being extremely versatile. Polydimethylsiloxane (PDMS), in spite of its well-defined helical structure, is an amorphous fluid even at extremely high molecular weights. The cause of this behavior is the high flexibility of the siloxane backbone and the lack of intermolecular interactions attributed to the presence of methyl groups. These make PDMS incompatible with almost any organic or inorganic component leading to phase separation in copolymers and blends. The material itself is hydrophobic and permeable to gases, with low viscosity, solubility parameters, low glass transition temperature and very low surface tension. This makes the silicones spread very easily, distinguished by their ability to form temporary films and thin coatings to more substantial durable films or with self-leveling and adhesive capacities as stand-alone sheets of different sizes and thickness, from a few micrometers to a few millimeters. One application that is based on this property is the formation of free standing, flexible submicrometric films of interest as active elements in certain devices, such as dielectric elastomer transducers (DETs). Dielectric elastomers (DEs), three-dimensional networks of long and flexible polymer chains, are soft active materials showing promising properties that mimic natural muscle for use in advanced robotics and smart prosthetics, as well as in haptic and microfluidic devices. They enjoy great interest due to their inherent flexibility, large strain, high efficiency, high energy density, and fast response of the material. In addition, some of their properties can be adjusted as required by chemical, physical or combined approaches. 
  • 1.1K
  • 23 Jun 2021
Topic Review
Aliphatic Polyesters by ADMET Polymerization and Hydrogenation
The recent developments of the synthesis of bio-based long-chain aliphatic polyesters by the acyclic diene metathesis (ADMET) polymerization of α,ω-dienes, derived from plant oils and bio-based chemicals, like bis(10-undecenoate) with isosorbide, using ruthenium-carbene catalysts. The development of subsequent (one-pot) tandem hydrogenation produced saturated polyesters under mild conditions.
  • 1.1K
  • 06 Feb 2024
Topic Review
Synthesis of Polymers for Electrospun Nanofiber Membranes
The use of nanofiber a filtering medium is well established, and the electrospun nanofiber have several applications such as electrospun fibers for air purification and air filtration media. The different characteristics of nanofibers as morphologies, mechanical and optical properties, thermal stability, electrical conductivity, photocatalytic activity and bioactivity underlie their macromolecular structure and chemical composition. 
  • 1.0K
  • 08 Feb 2023
Topic Review
Simultaneous Production of Cellulose Nitrates and Bacterial Cellulose
The scientific hypothesis about the possibility of simultaneous production of two independent of each other products from Miscanthus giganteus, namely the product of chemical modification of cellulose - cellulose nitrates and the product of biosynthesis - bacterial cellulose was tested.
  • 1.0K
  • 27 Dec 2023
Topic Review
Microplastics Derived from Food Packaging Waste
Plastics are commonly used for packaging in the food industry. The most popular thermoplastic materials that have found such applications are polyethylene (PE), polypropylene (PP), poly(ethylene terephthalate) (PET), and polystyrene (PS). Unfortunately, most plastic packaging is disposable. As a consequence, significant amounts of waste are generated, entering the environment, and undergoing degradation processes. They can occur under the influence of mechanical forces, temperature, light, chemical, and biological factors. These factors can present synergistic or antagonistic effects. As a result of their action, microplastics are formed, which can undergo further fragmentation and decomposition into small-molecule compounds. During the degradation process, various additives used at the plastics’ processing stage can also be released. Both microplastics and additives can negatively affect human and animal health.
  • 1.0K
  • 29 Jan 2023
Topic Review
PEDOT-based Catalytic Counter Electrode Material
Dye-sensitized solar cells (DSSCs) emerged in the early 1990s as a promising alternative to the classic silicon-based solar cell due to their unique combination of low cost, ease of fabrication, color palette for building integration, and high efficiency in indoor applications. 
  • 1.0K
  • 08 May 2021
Topic Review
Directed Assembly of Particle-Polymer Composites
Particle-polymer dispersions are ubiquitous in additive manufacturing (AM), where they are used as inks to create composite materials with applications to wearable sensors, energy storage materials, and actuation elements. It has been observed that directional alignment of the particle phase in the polymer dispersion can imbue the resulting composite material with enhanced mechanical, electrical, thermal or optical properties. 
  • 1.0K
  • 17 Aug 2021
Topic Review
Supercritical Carbon-di-Oxide Technology for Polymeric-Particles
Supercritical carbon dioxide (SC-CO2)  based techniques can be exploited for the formulation of polymeric nanocarriers, limiting the use of toxic organic solvent. The currently approved FDA pharmaceutical polymers like PLA and PLGA particles can be obtained in the micro-and nanometer range by techniques that involve SC-CO2 as solvent (RESS, RESOLV), anti-solvent (SAS, SEDS, SAILA) or extractant (SFEE), depending on the SC-CO2 compatibility with the system materials and the final product.
  • 1.0K
  • 27 Apr 2021
Topic Review
Covalent Organic for Solar Fuel
Harnessing solar energy and converting it into renewable fuels by chemical processes, such as water splitting and carbon dioxide (CO2) reduction, is a highly promising yet challenging strategy to mitigate the effects arising from the global energy crisis and serious environmental concerns. In recent years, covalent organic framework (COF)-based materials have gained substantial research interest because of their diversified architecture, tunable composition, large surface area, and high thermal and chemical stability. Their tunable band structure and significant light absorption with higher charge separation efficiency of photoinduced carriers make them suitable candidates for photocatalytic applications in hydrogen (H2) generation, CO2 conversion, and various organic transformation reactions. 
  • 1.0K
  • 13 Jul 2021
Topic Review
Natural Polymer-Based Hydrogels for Glaucoma Therapy
Biopolymers have been extensively investigated in a number of medical fields, including tissue engineering and drug delivery. This is largely due to the fact that they are biodegradable within the body, and do not induce an inflammatory reaction. Polynucleotides such as nucleic acids (DNA and RNA), proteins such as polypeptides, and polyesters derived from both plants and animals are also used. When compared to synthetic polymers, naturally occurring biopolymers and their derivatives have acquired preference, and have a comprehensive range of applications in pharmaceutical as well as biomedical research. Natural biopolymers are preferred for medical applications due to their biodegradability, biostability, biocompatibility, and non-toxicity. Additionally, natural polymers have the advantage of being readily available, economically friendly, and ecofriendly. Hydrogels designed from natural polymers exhibit high potential as drug delivery systems for biomaterials to treat ocular impairments.
  • 1.0K
  • 28 Jun 2022
Topic Review
Polymer Membranes in Contamination Situations
Depending on the type of contamination, various methods are used, including sorption, biodegradation, separation, or ion exchange processes in which membranes play an important role. The type of membrane is selected in respect of both the environment and the type of neutralized pollutants.
  • 1.0K
  • 17 Jun 2021
Topic Review
Weak Polyelectrolytes for Nanoarchitectonic Design Tools
The ionization degree, charge density, and conformation of weak polyelectrolytes can be adjusted through adjusting the pH and ionic strength stimuli. Such polymers thus offer a range of reversible interactions, including electrostatic complexation, H-bonding, and hydrophobic interactions, which position weak polyelectrolytes as key nano-units for the design of dynamic systems with precise structures, compositions, and responses to stimuli. From surface platforms to colloids and gels, weak polyelectrolytes have enabled the development of a wide range of functional materials owing to their intrinsic response to stimuli, including solvents, temperature, pH, and salt.
  • 1.0K
  • 30 May 2022
Topic Review
Biocomposite Based on Natural Polymers
Biopolymers are materials obtained from renewable resources. Despite the exciting properties of biopolymers, such as biocompatibility and environmental sustainability, they do not present antimicrobial properties (except chitosan). However, this lack of antimicrobial properties can be solved by incorporating or encapsulating antimicrobial agents. Natural polymers possess low stability in aqueous media and limited mechanical strength, which could be improved through cross-linking strategies. Hydrogels are biocompatible materials that can be synthesized from natural polymers, forming a cross-linking material. Alginate, collagen, fibrin, chitosan, gelatin, and hyaluronic acid are some natural polymers used to synthesize hydrogels.
  • 1.0K
  • 12 Jul 2022
Topic Review
Crosslinked nanogel for cancer theranostics
Crosslinked nanogels the structures of which are covalently crosslinked have better physiological stability than micelles and liposomes, making them more suitable for cancer theranostics. The applications of nanogels in drug and gene delivery as well as development of novel cancer therapeutic methods are first introduced, followed by the introduction of applications in optical and multimodal imaging, and imaging-guided cancer therapy. 
  • 1.0K
  • 01 Sep 2020
Topic Review
Mucoadhesive and Mucopenetrating Polymer-Based Adjuvants
Mucus is a viscoelastic gel that acts as a protective barrier for epithelial surfaces. The mucosal vehicles and adjuvants need to pass through the mucus layer to make drugs and vaccine delivery by mucosal routes possible. The mucoadhesion of polymer particle adjuvants significantly increases the contact time between vaccine formulations and the mucosa; then, the particles can penetrate the mucus layer and epithelium to reach mucosa-associated lymphoid tissues.
  • 1.0K
  • 23 May 2023
Topic Review
Crosslinking Density in Imprinting Polymerization
The crosslinking density of a material determines its physical properties, such as the porosity of the material. In imprinting polymerizations, the porosity determines access to internal binding sites and thus the capacity of the imprinted material. This entry is about effect of the commonly used crosslinking density in imprinting polymerization for a variety of applications.
  • 1.0K
  • 30 Sep 2021
Topic Review
Chemical Recycling for Plastic Waste
Plastics play an integral role in shaping our modern society and are ubiquitous in our daily lives. Their superior material characteristics, performance, and low production cost make them desirable for vast consumer and industrial applications. Chemical or feedstock recycling refers to any reprocessing technology directly affecting the formulation of polymeric waste or the polymer itself.  The recycling plastic waste through chemical means are explored.
  • 1.0K
  • 23 May 2023
Topic Review
Microplastics Invading Human Organs and Bodily Fluids Systems
Microplastics (MPs), small plastic particles resulting from the degradation of larger plastic items and from primary sources such as textiles, engineered plastic pellets, etc., have become a ubiquitous environmental pollutant. As their prevalence in the natural environment grows, concerns about their potential impacts on human health have escalated.
  • 1.0K
  • 20 Nov 2023
Topic Review
Glass–fibre–reinforced Polymer
Wind barrier structures are usually installed on railway bridges to reduce wind effects on travelling trains for safety considerations. This however adversely transfers wind loads and causes associated aerodynamic effects to the bridge. An innovative concept of wind barriers using glass fibre reinforced polymer (GFRP) composites is proposed in this work with experimental investigations and numerical modelling. This work provides a solution to mitigate the wind and associated aerodynamic loads. With an appropriate design of bending stiffness, the proposed barriers may deform adaptively in strong wind scenarios and let the wind to pass through their deformed shape and therefore transfer less load to the bridge. Wind-tunnel experiments and numerical studies are conducted on the aerodynamic responses of the train-barrier-bridge system under crosswind with various speeds. The influences of barrier height, air-flow speed and location of the train on the aerodynamic responses of the system were clarified. Both reduced-scale and full-scale finite element models were established for the train-barrier-bridge system and the results were validated with the experimental results to further support the research findings.
  • 1.0K
  • 22 Oct 2020
Topic Review
Solid-State Zinc Secondary Batteries with Alkaline Electrolytes
Aqueous zinc-ion batteries (ZIBs) have gained significant recognition as highly promising rechargeable batteries for the future due to their exceptional safety, low operating costs, and environmental advantages. Alkaline electrolytes have a long history of application in zinc-ion batteries. Alkaline electrolytes offer several advantages compared to neutral and acidic electrolytes. The benefits of alkaline electrolytes encompass a high operating voltage, rapid reaction kinetics, and enhanced ionic conductivity. KOH is the preferred alkaline electrolyte in rechargeable zinc batteries due to its notable characteristics such as the high solubility of zinc salt in KOH solution and the superior ionic conductivity of K+ (73.5 S cm−2) compared to Na+ (50.1 S cm−2) and Li+ (38.7 S cm−2). 
  • 996
  • 17 Oct 2023
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