Special Issue "Inorganic Syntheses Assisted by Microwave Heating"
A special issue of Inorganics (ISSN 2304-6740).
Deadline for manuscript submissions: 30 May 2014
Prof. Dr. Cristina Leonelli
Dipartimento di Ingegneria "Enzo Ferrari", Universita' degli Studi di Modena e Reggio Emilia, Via Vignolese 905/A, 41125 Modena, Italy
Interests: microwave assisted synthesis; hydrothermal synthesis; combustion synthesis; nanoparticles preparations; electrophoretic deposition; materials chemistry; geopolymers and glasses from inorganic wastes
Prof. Dr. Sridhar Komarneni
College of Agricultural Sciences,The Pennsylvania State University, PA 16802, USA
Interests: Crystal chemistry of clays and zeolites; chemistry of hydrous metal oxides in relation to cation separations and purification; water sorption and desorption, nuclear and hazardous waste disposal; kinetics and thermodynamics of cation exchange processes in minerals; Low temperature nanophase and nanocomposite materials; sol-gel chemistry of high-performance ceramics; hydrothermal and microwave-hydrothermal processing; new materials preparation and characterization
Microwave irradiation has been used for many years to accelerate chemical reactions. Nevertheless, over the years a more complex view has emerged because of detailed work by many researchers, primarily in the field of organic chemistry. Inorganic chemists have exploited the advantages of microwave heating not only for its accelerated temperature ramp up, but also for shortening reaction times which could lead to metastable phases or high purity products. The most investigated preparation procedure is, undoubtedly, the solvothermal and hydrothermal synthesis of powders where a drastic reduction of treatment time, from hours to minutes, have been clearly shown. The effects of microwave irradiation on the different crystal morphologies and sizes and crystallinity have been thoroughly investigated but challenges still remain, for example, in the preparation of mixed oxides, hydrated minerals, and many others. The second most investigated area is in the field of nanoparticle preparation, where homogeneous growth rate may occur. In this regard, we should also consider the selective heating of microemulsions where microwaves have played a unique role. Again speaking of nanoparticles, some of the most known preparation techniques are based on ignition by plasma torches ignited and sustained by microwaves. This particular synthetic approach has not yet been applied to all classes of compounds. Of great importance are also all the solid state reactions which are favoured by microwaves especially when low thermal conductive pellets are used. In these cases, diffusion studies are still at their beginning. Also sol–gel preparation of novel compounds can be greatly improved by the volumetric heating which is typical of microwave irradiation. At the end of the list, but not in terms of their importance, are the combustion syntheses which could take advantage of the microwave electromagnetic energy even though they are amongst the most exothermic reactions. The prolongation of a combustion until the consumption of the reactant is possible only under microwaves where combustion temperatures could be prolonged with significant effects on the final morphology of the products.
Microwave apparatuses and reactors with temperature and pressure monitoring devices have been under development in recent years, although several commercial outfits are actively supplying such equipment. The combination of different techniques being the most advanced trends: the combination of microwave irradiation with UV light or ultrasound stimulation, and pressure and laser excitations are just a few of the possibilities. These combinations represent a unique possibility to realize extreme environments with non- expensive devices which are not yet well known to the general synthesis community. Furthermore, the new developments in flow reactors with the advent of microreactors make microwaves even more interesting as a clean and sustainable heating source.
This special issue would deal with the state of the art in inorganic syntheses under microwave irradiation, and welcomes comprehensive reviews and research articles to bring out the widest information available to date, in all of the above areas and beyond; the primary requisite being a basic understanding of the heating mechanism and a complete monitoring of the reaction parameters.
Prof. Dr. Cristina Leonelli
Prof. Dr. Sridhar Komarneni
Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. Papers will be published continuously (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.
Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are refereed through a peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Inorganics is an international peer-reviewed Open Access quarterly journal published by MDPI.
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- dielectric heating
- microwave reactors
- microwave ignition
- microwave plasma
- microwave-hydrothermal syntheses
- microwave-ultrasonic combined syntheses
The below list represents only planned manuscripts. Some of these manuscripts have not been received by the Editorial Office yet. Papers submitted to MDPI journals are subject to peer-review.
Type of Paper: Article
Title: Microwave-Assisted Synthesis of Boron-Modified TiO2 Nanocrystals
Authors: Claudia Carlucci 1 and Giuseppe Ciccarella 2 et al.
1 CNR Istituto Nanoscienze, Lecce, Italy
2 Dipartimento di Ingegneria dell'Innovazione Universita' del Salento, Lecce, Italy
Abstract: An efficient microwave-assisted synthesis of [TiO2:(B)] nanorods, using titanium tetraisopropoxide (TTIP), benzyl alcohol as solvent, together with boric acid and oleic acid as additive reagents, has been developed. Chemical modification of TTIP by oleic acid was demonstrated as a rational strategy to tune the shape of TiO2 nanocrystals toward nanorod formation. The differently shaped [TiO2:(B)] nanocrystals were characterized in detail by Transmission Electron Microscopy (TEM), Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES), X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Raman Spectroscopy and Nitrogen Absorption-Desorption. The photocatalytic activity of TiO2 nanocrystals, under visible light irradiation, was also evaluated.
Title: High-Energy-Low-Temperature Technologies for the Synthesis of Nanoparticles and their Consolidation: Microwaves, Ultrasounds, High Pressure
Authors: Witlold Lojkowski, Cristina Leonelli, Tadeusz Chudoba, JacekWojnarowicz, Sylwia Kusnieruk, Aleksandra Kedzierska, Elzbieta Pietrzykowska, Dariusz Smolen, Agnieszka Opalinska, Andrzej Majcher and Adam Mazurkiewicz
1 Polish Academy of Sciences, Sokolowska 29, 01-142, Warsaw, Poland
2 Dipartimento di Ingegneria "Enzo Ferrari", Universita' degli Studi di Modena e Reggio Emilia, Via Vignolese 905/A, 41125 Modena, Italy
Abstract: Microwave Solvothermal Synthesis (MSS) is a solvothermal synthesis process with microwave heating. Besides possible effects of microwaves on the chemical reaction paths, microwave heating permits first of all to plan precisely a time-temperature schedule, as well as to achieve high super-saturation of the reagents uniformly in the reactor vessel volume. Thus, it is suitable for the production of nanoparticles with small grain size distribution and a high degree of crystallinity. A further advantage of the technology is a much lower synthesis temperature than for gas phase, plasma or sol-gel technologies. New reactors are being developed to permit to exploit these advantages of the MSS technology of nanoparticles synthesis and scale up the production rate. The nanoparticles produced using the MSS technology need to be either consolidated into bulk materials or used to modify the properties of other materials, both at temperatures well below grain growth temperature or, in case of functionalised nanoparticles, at a temperature where the molecules attached to the surface do not undergo dissociation. For consolidation of nanoparticles into bulk nanomaterials, we use extreme pressures reaching 8 GPa. To form a strong coating to a surface, we use the ultrasonic technology and exploit the cavitation phenomenon. All these methods have one factor in common: the processing temperatures are low enough to ensure that the nano-sized structure is preserved, and high local energy density ensures high quality of the final product: nanoparticles, coatings, bulk nanomaterials.
Confirmed author list:
Duncan Gregory University of Glasgow
Cristina Leonelli Universita' degli Studi di Modena e Reggio Emilia
Claudia Carlucci CNR Istituto Nanoscienze
Witold Lojkowski Polish Academy of Sciences
Last update: 24 March 2014