Methods for the Synthesis of Endohedral Fullerenes

2021 ◽  
Vol 21 (4) ◽  
pp. 2446-2459
Author(s):  
Nazym Yerlanovna Akhanova ◽  
Dmitry Viktorovich Shchur ◽  
Anatoly Petrovich Pomytkin ◽  
Alexander Dmitrievich Zolotarenko ◽  
Anatoly Dmitrievich Zolotarenko ◽  
...  

In the present manuscript the authors show the progress recorded regarding the main synthesis methods of metal endo-fullerenes. Shown, that nowadays, the most productive and common method of producing endohedral fullerenes is the electric arc process due to the fact that (a) it is simple enough to introduce atoms into the plasma from solids and gases; (b) its performance is the highest among other methods; (c) gives a wide range of produced types of metallofullerenes in an inert atmosphere-mono-, di-, tri-metalfullerenes, metal carbide clusters, in a reactive atmosphere (N2, NH3)-metal nitride and cyanide clusters, heterofullerenes; (d) provides the greatest energy potential, which is likely to allow the introduction into the cells of fullerene molecules metal atoms with higher ionization energies than titanium (≥7 eV). The yield of metal endofullerenes is substantially higher than the “empty” fullerenes. In this case, the stabilization of both metal atoms and fullerene cells occurs. The quantitative and qualitative output of MEF is significantly affected by: (a) conditions of the process in the reactor: the gas pressure, its flow rate, temperature, amperage; the distance between the electrodes, and others, that is, those factors that determine the plasma temperature and the residence time of the reaction particles in it; (b) the composition of solid additives (salts, oxides, metal alloys) in the graphite anode and their quantitative (mol) ratio with carbon; (c) replacement of the inert atmosphere of the synthesis with the active one (helium-with nitrogen, ammonia, water vapor, CO and other gases).

2021 ◽  
Author(s):  
Patrick M. Woodward ◽  
Pavel Karen ◽  
John S. O. Evans ◽  
Thomas Vogt

This comprehensive textbook provides a modern, self-contained treatment for upper undergraduate and graduate level students. It emphasizes the links between structure, defects, bonding, and properties throughout, and provides an integrated treatment of a wide range of materials, including crystalline, amorphous, organic and nano- materials. Boxes on synthesis methods, characterization tools, and technological applications distil specific examples and support student understanding of materials and their design. The first six chapters cover the fundamentals of extended solids, while later chapters explore a specific property or class of material, building a coherent framework for students to master core concepts with confidence, and for instructors to easily tailor the coverage to fit their own single semester course. With mathematical details given only where they strengthen understanding, 400 original figures and over 330 problems for hands-on learning, this accessible textbook is ideal for courses in chemistry and materials science.


2014 ◽  
Vol 16 (43) ◽  
pp. 23869-23873 ◽  
Author(s):  
G. Raggi ◽  
A. J. Stace ◽  
E. Bichoutskaia

Calcium containing endohedral fullerenes are representative of a large group of molecular cages, which can be reversibly toggled between two stable states defined by the distribution of the polarisation charge.


Author(s):  
Totka Dodevska ◽  
Dobrin Hadzhiev ◽  
Ivan Shterev ◽  
Yanna Lazarova

Recently, the development of eco-friendly, cost-effective and reliable methods for synthesis of metal nanoparticles has drawn a considerable attention. The so-called green synthesis, using mild reaction conditions and natural resources as plant extracts and microorganisms, has established as a convenient, sustainable, cheap and environmentally safe approach for synthesis of a wide range of nanomaterials. Over the past decade, biosynthesis is regarded as an important tool for reducing the harmful effects of traditional nanoparticle synthesis methods commonly used in laboratories and industry. This review emphasizes the significance of biosynthesized metal nanoparticles in the field of electrochemical sensing. There is increasing evidence that green synthesis of nanoparticles provides a new direction in designing of cost-effective, highly sensitive and selective electrode-catalysts applicable in food, clinical and environmental analysis. The article is based on 157 references and provided a detailed overview on the main approaches for green synthesis of metal nanoparticles and their applications in designing of electrochemical sensor devices. Important operational characteristics including sensitivity, dynamic range, limit of detection, as well as data on stability and reproducibility of sensors have also been covered. Keywords: biosynthesis; green synthesis; nanomaterials; nanotechnology; modified electrodes


Author(s):  
Divya Zindani

Different biomaterials in the form of ceramics, metal alloys, composites, glasses, polymers, etc. have gained wide-range acceptance in the realm of medical sciences. Bioimplants from such biomaterials have been constructed and used widely for different clinical applications. With the continual progress, biomaterials that may be resorbed inside the body have been developed. These have done away with the major challenge of removal of an implant after it has served its intended function. Important factors are taken into consideration in design and development of implants from such biomaterials are mechanical properties, degradation rate, surface modification, rate of corrosion, biocompatibility, and non-toxicity. Given the importance of such materials in clinical applications, the chapter presents an overview of the bioresorable composites and their implants. The related properties and the functions served have been outlined briefly. Further, the challenges associated and the remedies to overcome them have also been delineated.


Author(s):  
Divya Zindani

Different biomaterials in the form of ceramics, metal alloys, composites, glasses, polymers, etc. have gained wide-range acceptance in the realm of medical sciences. Bioimplants from such biomaterials have been constructed and used widely for different clinical applications. With the continual progress, biomaterials that may be resorbed inside the body have been developed. These have done away with the major challenge of removal of an implant after it has served its intended function. Important factors are taken into consideration in design and development of implants from such biomaterials are mechanical properties, degradation rate, surface modification, rate of corrosion, biocompatibility, and non-toxicity. Given the importance of such materials in clinical applications, the chapter presents an overview of the bioresorable composites and their implants. The related properties and the functions served have been outlined briefly. Further, the challenges associated and the remedies to overcome them have also been delineated.


Nanomaterials ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 145 ◽  
Author(s):  
Angela De Bonis ◽  
Mariangela Curcio ◽  
Antonio Santagata ◽  
Agostino Galasso ◽  
Roberto Teghil

Transition metal carbide nanoparticles are a class of technological interesting materials with a wide range of applications. Among metal carbides, tantalum carbides have good compatibility with the biological environment while molybdenum carbides are used as catalyst in electrochemical reactions. Laser ablation of bulk transition metal targets in some liquids is here reported and laser ablation in organic solvents is used as simple synthetic strategy for the production of carbide nanostructures. Herein, the nanoparticles produced by ultra-short laser ablation of tantalum and molybdenum in water, acetone, ethanol and toluene have been characterized by TEM, XRD and XPS analysis. The combined effect of metal and solvent chemical and physical properties on the composition of the nanomaterials obtained has been pointed out. In particular, the different reactivity of Ta and Mo with respect to oxidizing species determines the composition of particles obtained in water, on the other hand the organic solvents decomposition allows to obtain transition metal carbide (TMC) nanoparticles. The observed carbonaceous shell formed on TMC allows to protect the particle’s carbidic core and to improve and tailor the applications of these nanomaterials.


Author(s):  
Duncan Coppersthwaite ◽  
Howard Greenwood ◽  
Tahera Docrat ◽  
Sarah Allinson ◽  
Ruqayyah Sultan ◽  
...  

Organic compounds of various kinds have been used in the nuclear industry for numerous duties in uranium chemical, metal and ceramic processing plants. In the course of the various operations undertaken, these organic compounds have become contaminated with uranic material, either accidentally or as an inevitable part of the process. Typically, the chemical/physical form and/or concentration of the uranic content of the organics has prevented disposal. In order to address the issue of contaminated liquid organic wastes, the National Nuclear Laboratory (NNL) has developed a suite of treatments designed to recover uranium and to render the waste suitable for disposal. The developed processes are operated at industrial scale via the NNL Preston Laboratory Residue Processing Plant. The Oil Waste Leaching (OWL) Process is a fully industrialised process used for the treatment of contaminated oils with approximately 200 tonnes of uranium contaminated oil being treated to date. The process was originally developed for the treatment of contaminated tributyl phosphate and odourless kerosene which had been adsorbed onto sawdust. However, over the years, the OWL process has been refined for a range of oils including “water emulsifiable” cutting oils, lubricating oils, hydraulic oils/fluids and “Fomblin” (fully fluorinated) oils. Chemically, the OWL process has proved capable of treating solvents as well as oils but the highly volatile/flammable nature of many solvents has required additional precautions compared with those required for oil treatment. These additional precautions led to the development of the Solvent Treatment Advanced Rig (STAR), an installation operated under an inert atmosphere. STAR is a small “module” (100 dm3 volume) which allows the treatment of both water miscible and immiscible solvents. This paper discusses the challenges associated with the treatment of liquid organic wastes and the process developments which have allowed a wide range of materials to be successfully treated.


Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1009
Author(s):  
Suresh Thangudu ◽  
Mu Tzu Lee ◽  
Sami Rtimi

Molybdenum Sulfide nanosheets (MoS2 NSs) have unique properties that allow its use in a wide range of applications. Unfortunately, a lack of green synthesis methods to achieve a high yield remains a challenge after decades. Herein we report a simple, ecofriendly, green and cost-effective approach to synthesize water soluble MoS2 NSs via probe/Tip sonication method. The sequential batch manner pathway allows us to attain a high yield of MoS2 NSs (~100%). The prepared MoS2 NSs were characterized using up-to-date surface science techniques. UV-visible-NIR spectroscopy allowed us to visualize the doublet peaks of pristine MoS2 at 610 and 680 nm concomitant with the inter-band transitions at 394 nm and 460 nm. Using Transmission Electron Microscopy (TEM) and Dynamic Light Scattering (DLS), the crystallites’ sizes were estimated. X-ray diffraction (XRD) and Raman Spectroscopy were performed with respect to the bulk MoS2. The energy difference between the Raman peaks revealed that our NSs are formed of 5–6 layers. Further, we explored enzyme peroxidase mimetic properties of the synthesized MoS2 NSs. Results showed that the present MoS2 NSs offer excellent peroxidase mimicking properties. Most importantly, we observed that the optical properties and characteristics of MoS2 NSs synthesized by the current green method are similar to those of MoS2 NSs synthesized using conventional harsh methods reported in the literature. So that we strongly assume that the present method is a green alternative for the existing low yield and harsh experimental procedures to achieve water soluble MoS2 NSs in high yield. The synthesized soluble NSs are promising catalysts for the detection of toxic chemicals in the environment and/or for following enzymatic chromogenic reactions.


1973 ◽  
Vol 28 (11) ◽  
pp. 1794-1800 ◽  
Author(s):  
Horst Ehrich ◽  
Hans Jürgen Kusch

The profiles of the Stark broadened Balmer lines Hα and Hβ have been measured in a wide range of temperature and electron density. By the use of different light sources (3 wallstabilized arcs of different design, a pulsed discharge tube and a plexiglass-capillary discharge) the range was ex- tended to 1.0·104≦T≦3.2·104 °K for the plasma temperature and to 1·1016≦ne≦55·1016 cm−3 for the electron density in the Hβ-scale. The experimental profiles of the Hα-line agree with generalized impact approximations if the condition: ne2/3/T>2·107 cm−2 grad−1 is fulfilled. Disagreements between the Hα and Hβ electron density scale can be removed applying an empirical correction-factor to the electron density obtained from the half-width of Hα.


Author(s):  
Oana Cadar ◽  
Thomas Dippong ◽  
Marin Senila ◽  
Erika-Andrea Levei

Engineered nanomaterials with tailored properties are highly required in a wide range of industrial fields. Consequently, the researches dedicated to the identification of new applications for existing materials and to the development of novel promising materials and cost effective, eco-friendly synthesis methods gained considerable attention in the last years. Cobalt ferrite is one of the nanomaterials with a wide application range due to its unique properties such as high electrical resistivity, negligible eddy current loss, moderate saturation magnetization, chemical and thermal stability, high Curie temperature and high mechanical hardness. Moreover, its structural, magnetic and electrical properties can be tailored by the selection of preparation route, chemical composition, dopant ions and thermal treatment. This chapter presents the recent applications of nanosized cobalt ferrites doped or co-doped with divalent transition ions such as Zn2+, Cu2+, Mn2+, Ni2+, Cd2+ obtained by various synthesis methods in ceramics, medicine, catalysis, electronics and communications.


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