Log in/Sign up
Arts & Humanities
Biology & Life Sciences
Business & Economics
Chemistry & Materials Science
Computer Science & Mathematics
Environmental & Earth Sciences
Medicine & Pharmacology
Public Health & Healthcare
Two-dimensional (2D) materials are generally defined as crystalline substances with a few atoms thickness.Two-dimensional transition metal dichalcogenide (2D-TMDs) semiconducting (SC) materials have exhibited unique optical and electrical properties. The layered configuration of the 2D-TMDs materials is at the origin of their strong interaction with light and the relatively high mobility of their charge carriers, which in turn prompted their use in many optoelectronic applications, such as ultra-thin field-effect transistors, photo-detectors, light emitting diode, and solar-cells. Generally, 2D-TMDs form a family of graphite-like layered thin semiconducting structures with the chemical formula of MX2, where M refers to a transition metal atom (Mo, W, etc.) and X is a chalcogen atom (Se, S, etc.). The layered nature of this class of 2D materials induces a strong anisotropy in their electrical, chemical, mechanical, and thermal properties. In particular, molybdenum disulfide (MoS2) is the most studied layered 2D-TMD.
28 Sep 2021
GeSn Alloys for Photonic and Electronic Applications
GeSn materials have attracted considerable attention for their tunable band structures and high carrier mobilities, which serve well for future photonic and electronic applications.
28 Mar 2022
Polycrystalline materials can be defined as the counterpart of single crystals. These latter arise from solution crystallization by transfer of a solute from the liquid phase to the crystalline phase. Crystallization from melt originates instead crystallites or grains, that is regular crystalline regions randomly oriented and separated one anoher by borders with geometric shapes, Polycrystalline materials are the result of a multiple nucleation process, whereas monocrystals are ideally obtainable by dipping a seed crystal into a supercooled melt. Polycrystalline materials often consist of spherulites, i.e. crystalline aggregates growing with a rounded shape up to impingment with adjacent spherulites. The borders amongst spherulites and the size and the final shape of spherulites affect considerably the properties of polycrystalline materials.
12 May 2021
Dimensionality of materials
As generally known dimensionality of materials is a crucial factor to determine functions and properties of the materials. In addition to zero-dimensional, one-dimensional, three-dimensional, and further integrated functional materials, various two-dimensional materials have been paid special attention. Two-dimensional materials have their unique electronic propertiesand play important roles in interfacial sciences.
12 Aug 2021
Gold and Silver Nanoparticle-Based Colorimetric Sensors
Gold and Silver nanoparticles (AuNPs and AgNPs) are perfect platforms for developing sensing colorimetric devices thanks to their high surface to volume ratio and distinctive optical properties, particularly sensitive to changes in the surrounding environment. These characteristics ensure high sensitivity in colorimetric devices. Au and Ag nanoparticles can be capped with suitable molecules that can act as specific analyte receptors, so highly selective sensors can be obtained.
23 Nov 2021
Clinoptilolite Characterization and EDS Analysis
Zeolites are materials of biomedical interest, in particular owing to their ability to remove metabolic products such as uremic toxins (i.e., urea, uric acid, creatinine, p-cresol, and indoxul sulfate); they are used for the regeneration of dialysis solutions and as in vivo membranes for artificial kidney. Zeolites have further important applications in the biomedical field, in fact they are used as hemostats (due to their ability to absorb water), antiseptics (when modified with silver or zinc ions), carriers for drugs and genes (adjuvant in vaccines), glucose absorbers, etc. Here, EDS microanalysis in the study of a sample of natural clinoptilolite is reported.
28 Sep 2021
Design Challenges and Limitations of Injectable Hydrogels
Injectable hydrogels (IHs) are smart biomaterials and are the most widely investigated and versatile technologies, which can be either implanted or inserted into living bodies with minimal invasion. Their unique features, tunable structure and stimuli-responsive biodegradation properties make these IHs promising in many biomedical applications, including tissue engineering, regenerative medicines, implants, drug/protein/gene delivery, cancer treatment, aesthetic corrections and spinal fusions. Regarding their current prospective and ongoing research, hydrogel formulations have some limitations in their applications, clinical practices and sustainability. Many hydrogel systems (natural/synthetic), such as thermosensitive hydrogels, are free-flowing sols at a low temperature, while upon raising to body temperature (physiological temperature), they are converted to a stable visco-elastic gel phase, such as poly (phosphazene), pluronic and poly (N-isopropyl acrylamide).
08 Apr 2022
High Temperature Tribology
High temperature tribology is considered to begin from a minimum temperature of 300–350 °C, where organic base oils and polymers begin to decompose, until a temperature of 1000 °C. In this field of tribology, tests are typically run under dry or solid-state friction, unless a solid lubricant is used, since most lubricants will oxidize or break down when exposed to these extreme temperatures. Therefore, this form of tribotesting is useful to determine the friction, wear, and other tribological characteristics of coatings, ceramics, alloys, cermets, and similar materials.
30 Apr 2021
Nanomaterials for Industrial Wastewater Treatment
Industrial wastewater originating from various industries contributes as a major source of water pollution. This pollutant poses a severe threat to the environment. Recent years saw nanomaterials as a potential candidate for pollutants removal. Nowadays, a range of cost-effective nanomaterials is available with unique properties.
22 Jul 2021
Particle-Bound Mercury Characterization
Particulate Bound Hg (PBM) consists of all airborne particulate containing Hg, including both stable condensed and gaseous forms adsorbed on atmospheric particulate matter (PM); it is operationally sampled and quantified by pulling air through a glass fiber or a quartz filter. PBM usually includes all those particles with a diameter <2.5 μm, even if its characterization depends on the pore size of the filter used for its collection. The accurate dimensional characterization is then essential to estimate the dry deposition of PBM, as well as any other particulate pollutant; the particles diameters directly influence gravitational sedimentation and the PBM residence time in the atmosphere. In addition, PBM chemical speciation, as well as for the other Hg forms, is fundamental to understand PBM bioavailability and therefore the effects on human .
05 Jul 2021
Featured Entry Collections
Encyclopedia of Social Sciences
Encyclopedia of ZEMCH Research and Development
Encyclopedia of Engineering
Encyclopedia of Piezoelectrics
Log in/Sign up
Terms and Conditions
Browse our user manual, common Q&A, author guidelines, etc.
Rate your experience
Let us know your experience and what we could improve.
Report an error
Is something wrong? Please let us know!
Other feedback you would like to report.
Did you find what you were looking for?
Do you agree to share your valuable feedback publicly on
Yes, I agree. Encyclopedia can post it.
No, I do not agree. I would not like to post my testimonial.
Upload a screenshot
(Max file size 2MB)