Topic Review
Nanoparticle Exsolution on Perovskite-Based Catalysts
In heterogeneous catalysis, surfaces decorated with uniformly dispersed, catalytically-active (nano)particles are a key requirement for excellent performance. Besides standard catalyst preparation routines—with limitations in controlling catalyst surface structure (i.e., particle size distribution or dispersion)—exsolution is a potential novel and time efficient route to precisely tailor catalyst surface morphology and composition of perovskites: Perovskite-type oxides of nominal composition ABO3 with transition metal cations on the B-site can exsolve the B-site transition metal upon controlled reduction. In this exsolution process, the transition metal emerges from the oxide lattice and migrates to the surface where it forms catalytically active nanoparticles. Doping the B-site with reducible and catalytically highly active elements, offers the opportunity of tailoring properties of exsolution catalysts.
  • 1.4K
  • 01 Nov 2020
Topic Review
Poly(Butylene Adipate-Co-Terephthalate)/Calcium Carbonate Films
Poly(butylene adipate-co-terephthalate) (PBAT) is a biodegradable polymer synthesized from petrochemical resources. PBAT has an exceptionally high elongation at break values which makes it one of the most promising substitutes for LDPE packaging films. However, the applicability of PBAT films is still limited by low strength and high production costs. Polyethylene glycol 600 (PEG-600) was used as a coating agent to modify the surface of calcium carbonate and improve compatibility with the polymer matrix. A series of PBAT/CaCO3 composite films having different CaCO3 particle size and content of coating agent was prepared using extrusion blow molding. 
  • 1.4K
  • 28 Feb 2022
Topic Review
Fentanyl and Its New Analogs
Fentanyl is known as a synthetic narcotic analgesic, which can act as an agonist of opioid receptors, being about 100 times more potent than heroin or morphine.
  • 1.4K
  • 29 Mar 2022
Topic Review
Biofouling on Stainless Steel
In humid environments, the formation of biofilms and microfouling are known to be the detrimental processes that first occur on stainless steel surfaces. This is known as biofouling. Subsequently, the conditions created by metabolites and the activity of organisms trigger corrosion of the metal and accelerate corrosion locally, causing a deterioration in, and alterations to, the performance of devices made of stainless steel. The microorganisms which thus affect stainless steel are mainly algae and bacteria.
  • 1.4K
  • 24 Feb 2022
Topic Review
Structure-Based Drug Design
The functionality of a protein is dependent upon its structure, and structure-based drug design (SBDD) relies on the 3D structural information of the target protein, which can be acquired from experimental methods, such as X-ray crystallography, NMR spectroscopy and cryo-electron microscopy (cryo-EM). The aim of SBDD is to predict the Gibbs free energy of binding (ΔGbind), the binding affinity of ligands to the binding site, by simulating the interactions between them.
  • 1.4K
  • 09 Jan 2023
Topic Review
Composite Material Recycling Technology
The recycling of fiber reinforced composite materials will therefore play an important role in the future, in particular for the wind energy, but also for aerospace, automotive, construction and marine sectors to reduce environmental impacts and to meet the demand.
  • 1.4K
  • 18 Feb 2021
Topic Review
Hollow-Core Photonic Crystal Fibers
This entry briefly introduces hollow-core photonic crystal fibers (HC-PCF), and mainly discusses their applications in  fiber gas Raman lasers (FGRL) at 1.7μm band. A 1.7 μm pulsed laser plays an important role in bioimaging, gas detection, and so on. FGRLs based on HC-PCFs provide a novel and effective method for fiber lasers operating at 1.7 μm. Compared with traditional methods, FGRLs have more advantages in generating high-power 1.7 μm pulsed lasers.
  • 1.4K
  • 08 Feb 2021
Topic Review
NTC-Properties of a Geomorphic Clinoptilolite Sample
Negative temperature coefficient (NTC) materials are usually based on ceramic semiconductors, and electrons are involved in their transport mechanism. A new type of NTC material, adequate for alternating current (AC) applications, is represented by zeolites. Indeed, zeolites are single charge carrier ionic conductors with a temperature-dependent electrical conductivity. In particular, electrical transport in zeolites is due to the monovalent charge-balancing cations, like K+, capable of hopping between negatively charged sites in the aluminosilicate framework. Owing to the highly non-linear electrical behavior of the traditional electronic NTC materials, the possibility to have alternative types of materials, showing linearity in their electrical behavior, is very desirable. Among different zeolites, natural clinoptilolite has been selected for investigating NTC behavior since it is characterized by high zeolite content, a convenient Si/Al atomic ratio, good mechanical strength due to its compact microstructure, and low toxicity. Clinoptilolite has shown a rapid and quite reversible impedance change under heating, characterized by a linear dependence on temperature.
  • 1.4K
  • 11 Jul 2024
Topic Review
Chitosan and Chitosan Modified by Functionalization
The biomedical and therapeutic importance of chitosan and chitosan derivatives is the subject of interdisciplinary research. In this entry, researchers intended to consolidate some of the recent discoveries regarding the potential of chitosan and its derivatives to be used for biomedical and other purposes. Why chitosan? Because chitosan is a natural biopolymer that can be obtained from one of the most abundant polysaccharides in nature, which is chitin. Compared to other biopolymers, chitosan presents some advantages, such as accessibility, biocompatibility, biodegradability, and no toxicity, expressing significant antibacterial potential. In addition, through chemical processes, a high number of chitosan derivatives can be obtained with many possibilities for use. 
  • 1.4K
  • 02 Apr 2022
Topic Review
Titanium Dioxide for Water Purification
Titanium dioxide (TiO2), one of the most frequently used materials in general, has emerged as an excellent photocatalytic material for environmental applications. Here, principles and mechanisms of the photocatalytic activity of TiO2 have been analyzed. Structural and physical specificities of TiO2 nanoparticles, such as morphology, crystal structure, and electronic and optical properties, have been considered in the context of photocatalytic applications.
  • 1.4K
  • 16 Jan 2023
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