Inorganics 2014, 2(2), 191-210; doi:10.3390/inorganics2020191
Review

Direct Energy Supply to the Reaction Mixture during Microwave-Assisted Hydrothermal and Combustion Synthesis of Inorganic Materials

Received: 22 November 2013; in revised form: 23 January 2014 / Accepted: 28 April 2014 / Published: 5 May 2014
(This article belongs to the Special Issue Innovative Inorganic Synthesis)
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract: The use of microwaves to perform inorganic synthesis allows the direct transfer of electromagnetic energy inside the reaction mixture, independently of the temperature manifested therein. The conversion of microwave (MW) radiation into heat is useful in overcoming the activation energy barriers associated with chemical transformations, but the use of microwaves can be further extended to higher temperatures, thus creating unusual high-energy environments. In devising synthetic methodologies to engineered nanomaterials, hydrothermal synthesis and solution combustion synthesis can be used as reference systems to illustrate effects related to microwave irradiation. In the first case, energy is transferred to the entire reaction volume, causing a homogeneous temperature rise within a closed vessel in a few minutes, hence assuring uniform crystal growth at the nanometer scale. In the second case, strong exothermic combustion syntheses can benefit from the application of microwaves to convey energy to the reaction not only during the ignition step, but also while it is occurring and even after its completion. In both approaches, however, the direct interaction of microwaves with the reaction mixture can lead to practically gradient-less heating profiles, on the basis of which the main observed characteristics and properties of the aforementioned reactions and products can be explained.
Keywords: energy transfer; microwaves; hydrothermal synthesis; combustion synthesis; nanomaterials
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MDPI and ACS Style

Rosa, R.; Ponzoni, C.; Leonelli, C. Direct Energy Supply to the Reaction Mixture during Microwave-Assisted Hydrothermal and Combustion Synthesis of Inorganic Materials. Inorganics 2014, 2, 191-210.

AMA Style

Rosa R, Ponzoni C, Leonelli C. Direct Energy Supply to the Reaction Mixture during Microwave-Assisted Hydrothermal and Combustion Synthesis of Inorganic Materials. Inorganics. 2014; 2(2):191-210.

Chicago/Turabian Style

Rosa, Roberto; Ponzoni, Chiara; Leonelli, Cristina. 2014. "Direct Energy Supply to the Reaction Mixture during Microwave-Assisted Hydrothermal and Combustion Synthesis of Inorganic Materials." Inorganics 2, no. 2: 191-210.

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