Your browser does not fully support modern features. Please upgrade for a smoother experience.
Subject:
All Disciplines Arts & Humanities Biology & Life Sciences Business & Economics Chemistry & Materials Science Computer Science & Mathematics Engineering Environmental & Earth Sciences Medicine & Pharmacology Physical Sciences Public Health & Healthcare Social Sciences
Sort by:
Most Viewed Latest Alphabetical (A-Z) Alphabetical (Z-A)
Filter:
All Topic Review Biography Peer Reviewed Entry Video Entry
Topic Review
Plastic Waste into Supports for Nanostructured Heterogeneous Catalysts
Plastics are ubiquitous in our society and are used in many industries, such as packaging, electronics, the automotive industry, and medical and health sectors, and plastic waste is among the types of waste of higher environmental concern. The increase in the amount of plastic waste produced daily has increased environmental problems, such as pollution by micro-plastics, contamination of the food chain, biodiversity degradation and economic losses. The selective and efficient conversion of plastic waste for applications in environmental remediation, such as by obtaining composites, is a strategy of the scientific community for the recovery of plastic waste. The development of polymeric supports for efficient, sustainable, and low-cost heterogeneous catalysts for the treatment of organic/inorganic contaminants is highly desirable yet still a great challenge; this will be the main focus of this work. Common commercial polymers, like polystyrene, polypropylene, polyethylene therephthalate, polyethylene and polyvinyl chloride, are addressed herein, as are their main physicochemical properties, such as molecular mass, degree of crystallinity and others. Additionally, we discuss the environmental and health risks of plastic debris and the main recycling technologies as well as their issues and environmental impact. The use of nanomaterials raises concerns about toxicity and reinforces the need to apply supports; this means that the recycling of plastics in this way may tackle two issues. Finally, we dissert about the advances in turning plastic waste into support for nanocatalysts for environmental remediation, mainly metal and metal oxide nanoparticles.
  • 1.4K
  • 18 Jan 2022
Topic Review
Parameters Affecting Zeolite T Crystallization
Zeolites are well-known porous crystal systems that exist in various sizes (nano-, micro-, etc.) and have been widely incorporated in different applications. They consist of a uniform size of pore distributions which are also known as voids. Voids and cavities within the zeolite system are the factors that contribute to the unique properties of the zeolite. These voids and cavities are controlled by the type of crystals that grow and intergrowth within the zeolite membrane. Nanoporous zeolite T is identified to have within it an intergrowth framework that makes zeolite type T an exceptional species in the zeolite family.
  • 1.4K
  • 18 Jun 2021
Topic Review
Magnetic Polymer Nanocomposites for Aerospace Applications
Polymers have had an enormous impact on science and technology, and their interest relating to the development of new macromolecular materials has exponentially increased. Polymer nanocomposites, materials based on a polymeric matrix covalently coupled to reinforcement, display properties of both components. In the aerospace industry, polymer nanocomposites are attractive due to their promising characteristics, among which lightness, mechanical and thermal resistance, radiation and corrosion resistance, and conductive and magnetic properties stand out. The use of them, instead of metal-based materials, has allowed the optimization of design processes and applications in order to provide safer, faster, and eventually cheaper transportation in the future. 
  • 1.4K
  • 25 Oct 2022
Topic Review
Fiber Attrition and Micro-Voids
A discontinuous fiber-reinforced polymer composite (DFRPC) provides superior mechanical performances in material extrusion additive manufacturing (MEAM) parts, and thus promotes their implementations in engineering applications. The process-induced structural defects of DFRPCs increase the probability of pre-mature failures as the manufactured parts experience complicated external loads. The process-induced fiber length attrition and micro-voids formations in MEAM applications is provided. By gaining a clearer view of the correlations between the MEAM processing parameters, and tooling and the resulting microstructures of produced DFRPCs, it is expected to manufacture composites parts with more preferable mechanical properties via MEAM.
  • 1.3K
  • 24 Nov 2022
Topic Review
Polymer/Enzyme Composite Materials
A significant interest was granted to enzymes, which are versatile catalysts characterized by natural origin, with high specificity and selectivity for particular substrates. Additionally, some enzymes are involved in the production of high-valuable products, such as antibiotics, while others are known for their ability to transform emerging contaminates, such as dyes and pesticides, to simpler molecules with a lower environmental impact. Nevertheless, the use of enzymes in industrial applications is limited by their reduced stability in extreme conditions and by their difficult recovery and reusability. Rationally, enzyme immobilization on organic or inorganic matrices proved to be one of the most successful innovative approaches to increase the stability of enzymatic catalysts. By the immobilization of enzymes on support materials, composite biocatalysts are obtained that pose an improved stability, preserving the enzymatic activity and some of the support material’s properties. Of high interest are the polymer/enzyme composites, which are obtained by the chemical or physical attachment of enzymes on polymer matrices.
  • 1.3K
  • 31 Oct 2022
Topic Review
Biomedical Compositions Containing Hydroxyapatite
Regenerative medicine is becoming a rapidly evolving technique in today’s biomedical progress scenario. Scientists around the world suggest the use of naturally synthesized biomaterials to repair and heal damaged cells. Hydroxyapatite (HAp) has the potential to replace drugs in biomedical engineering and regenerative drugs. HAp is easily biodegradable, biocompatible, and correlated with macromolecules, which facilitates their incorporation into inorganic materials. 
  • 1.3K
  • 08 May 2021
Topic Review
Gelatin and Bioactive Glass Composites
Nano-/micron-sized bioactive glass (BG) particles are attractive candidates for both soft and hard tissue engineering. They can chemically bond to the host tissues, enhance new tissue formation, activate cell proliferation, stimulate the genetic expression of proteins, and trigger unique anti-bacterial, anti-inflammatory, and anti-cancer functionalities. Composites based on biopolymers and BG particles have been developed with various state-of-the-art techniques for tissue engineering. Gelatin, a semi-synthetic biopolymer, has attracted the attention of researchers because it is derived from the most abundant protein in the body, viz., collagen. It is a polymer that can be dissolved in water and processed to acquire different configurations, such as hydrogels, fibers, films, and scaffolds.
  • 1.3K
  • 28 Jan 2023
Topic Review
Applications of Bio-Epoxies in Composites
Despite the reliability of traditional epoxy systems, the increasing demand for sustainability has driven researchers and industries to explore new bio-based alternatives. Additionally, natural fibers have the potential to serve as environmentally friendly substitutes for synthetic ones, contributing to the production of lightweight and biodegradable composites. Enhancing the mechanical properties of these bio-composites also involves improving the compatibility between the matrix and fibers. In this sense, the use of bio-epoxy resins facilitates better adhesion of natural composite constituents, addressing sustainability and environmental concerns.
  • 1.3K
  • 11 Jan 2024
Topic Review
MNPs@QDs
The presence of food contaminants can cause foodborne illnesses, posing a severe threat to human health. Therefore, a rapid, sensitive, and convenient method for monitoring food contaminants is eagerly needed. The complex matrix interferences of food samples and poor performance of existing sensing probes bring significant challenges to improving detection performances. Nanocomposites with multifunctional features provide a solution to these problems. The combination of the superior characteristics of magnetic nanoparticles (MNPs) and quantum dots (QDs) to fabricate magnetic fluorescent quantum dots (MNPs@QDs) nanocomposites are regarded as an ideal multifunctional probe for food contaminants analysis.
  • 1.3K
  • 22 Apr 2022
Topic Review
Metal Hydrides and Graphene Supports
Energy production, distribution, and storage remain paramount to a variety of applications that reflect on our daily lives, from renewable energy systems, to electric vehicles and consumer electronics. Hydrogen is the sole element promising high energy, emission-free, and sustainable energy, and metal hydrides in particular have been investigated as promising materials for this purpose. While offering the highest gravimetric and volumetric hydrogen storage capacity of all known materials, metal hydrides are plagued by some serious deficiencies, such as poor kinetics, high activation energies that lead to high operating temperatures, poor recyclability, and/or stability, while environmental considerations related to the treatment of end-of-life fuel disposal are also of concern. Graphene is a 2D material with very appealing properties, highlighting its potential use as support for various reactive species, including metals and metal hydrides. By embedding hydride species into graphene supports, valuable nanocomposites can be obtained with direct use for energy storage applications.
  • 1.3K
  • 01 Jun 2023
Topic Review
Structures of Mechanoresponsive Smart Windows
Mechanically responsive smart windows have the advantages of simple structure, low cost and good stability.
  • 1.3K
  • 06 Mar 2023
Topic Review
Amine Type in CO2 Separation
Efficient CO2 capture technologies such as absorption/adsorption of CO2 sorbents, cryogenic separation, and membrane separation, have been developed experimentally and industrially. Among them, membrane technology is attracting growing attention owing to its inherent advantages that include energy-efficiency, ease of operation and scale-up, and a small footprint.
  • 1.3K
  • 27 Sep 2022
Topic Review
Cathodes for Magnesium-Sulfur Batteries
Large-scale energy storage with high performance and at a reasonable cost are prerequisites for promoting clean energy utilization. With a high theoretical energy density of 1722 Wh·kg−2, high element abundance (e.g., Mg of 23,000 ppm, S of 950 ppm on earth), and low theoretical cost, Mg-S batteries offer considerable potential as candidates for electrical energy storage.
  • 1.3K
  • 18 Apr 2023
Topic Review
Cement-Based Piezoelectric Ceramic Composites
Compatibility, a critical issue between sensing material and host structure, significantly influences the detecting performance (e.g., sensitive, signal-to-noise ratio) of the embedded sensor. To address this issue in concrete-based infrastructural health monitoring, cement-based piezoelectric composites (piezoelectric ceramic particles as a function phase and cementitious materials as a matrix) have attracted continuous attention in the past two decades, dramatically exhibiting superior durability, sensitivity, and compatibility.
  • 1.3K
  • 13 May 2021
Topic Review
Polyhydroxyalkanoates and Poly(lactic acid)'s Biodegradation
The synthesis process for two types of biopolymer: PHAs and PLA. Synthesis of PHAs involves bacteria fermentation and extraction procedure. PLA is chemically synthesised via condensation polymerization of lactic acid (LA).
  • 1.3K
  • 04 Jun 2021
Topic Review
Applications of Wind Turbine Blade Recycling Materials
The rapid growth of the wind energy industry has resulted in a significant increase in Wind Turbine Blade (WTB) waste, posing challenges for recycling due to the composite materials used in their construction. Each recycling technique employs distinct approaches, all to reclaim the valuable fibres in these blades. Mechanical recycling yields resin-rich, fibre-rich, and other qualities of byproducts, while pyrolysis generates fibres, fillers, gas, and oil.
  • 1.3K
  • 24 Nov 2023
Topic Review
Self-Healable Lithium-Ion Batteries
The inner constituents of lithium-ion batteries (LIBs) are easy to deform during charging and discharging processes, and the accumulation of these deformations would result in physical fractures, poor safety performances, and short lifespan of LIBs. The introduction of self-healing (SH) materials into electrodes or electrolytes can bring about great enhancements in their mechanical strength, thus optimizing the cycle stability of the batteries. Due to the self-healing property of these special functional materials, the fractures/cracks generated during repeated cycles could be spontaneously cured. 
  • 1.2K
  • 24 Nov 2022
Topic Review
Glass-Ceramic Solid-State Electrolytes for Lithium Batteries
The all-solid-state lithium battery (ASSLIB) is one of the key points of future lithium battery technology development. Because solid-state electrolytes (SSEs) have higher safety performance than liquid electrolytes, and they can promote the application of Li-metal anodes to endow batteries with higher energy density. Glass-ceramic SSEs with excellent ionic conductivity and mechanical strength are one of the main focuses of SSE research. 
  • 1.2K
  • 21 Apr 2023
Topic Review
Magnetic Properties and Magnetocaloric Effect of Pr2Co7 Compound
The Pr2Co7 compound has interesting magnetic properties, such as a high Curie temperature TC and uniaxial magnetocrystalline anisotropy. It crystallizes in a hexagonal structure (2:7 H) of the Ce2Ni7 type and is stable at relatively low temperatures (Ta ≤ 1023 K), or it has a rhombohedral structure (2:7 R) of the Gd2Co7 type and is stable at high temperatures (Ta ≥ 1223 K). Studies of the magnetocaloric properties of the nanocrystalline Pr2Co7 compound have shown the existence of a large reversible magnetic entropy change (ΔSM) with a second-order magnetic transition. 
  • 1.2K
  • 15 Jun 2023
Topic Review
Graphene-Based Nanomaterials for Lithium-Sulfur Batteries
The global energy crisis and environmental problems are becoming increasingly serious. It is now urgent to vigorously develop an efficient energy storage system. Lithium-sulfur batteries (LSBs) are considered to be one of the most promising candidates for next-generation energy storage systems due to their high energy density. Sulfur is abundant on Earth, low-cost, and environmentally friendly, which is consistent with the characteristics of new clean energy. Although LSBs possess numerous advantages, they still suffer from numerous problems such as the dissolution and diffusion of sulfur intermediate products during the discharge process, the expansion of the electrode volume, and so on, which severely limit their further development. Graphene is a two-dimensional crystal material with a single atomic layer thickness and honeycomb bonding structure formed by sp2 hybridization of carbon atoms. Since its discovery in 2004, graphene has attracted worldwide attention due to its excellent physical and chemical properties. 
  • 1.2K
  • 29 Apr 2021
  • Page
  • of
  • 12
Featured Entry Collections
>>

Featured Reprints

>>
Encyclopedia of Digital Society, Industry 5.0 and Smart City
Encyclopedia of Engineering
Encyclopedia of Social Sciences
Encyclopedia of Medieval Royal Iconography
Academic Video Service
Feedback

Quick Survey

Encyclopedia MDPI is conducting a targeted survey to identify the specific barriers hindering efficient research. We invite you to spend 3 minutes defining the priorities for our next generation of structured knowledge tools.
Take Survey