Microwave Chemistry in Silicon Carbide Reaction Vials: Separating Thermal from Nonthermal Effects

Obermayer, David; Gutmann, Bernhard; Kappe, C. Oliver

doi:10.1002/anie.200904185

Cited by 233 publications

(136 citation statements)

References 20 publications

(12 reference statements)

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“…50 There is an ongoing debate whether the enhancement of chemical reactions driven by microwave irradiation is due to rapid heating or whether it is due to selective interaction of electromagnetic field with polar molecules. Our microfluidic -microwave droplet heater, due to its ability to separate conventional heat transfer 55 mechanisms from dielectric heating 44 , can help shine light onto these questions. To separate the affects of conventional heating from dielectric heating, we utilize infrared imaging to visualize the heat distribution through the device.…”

Section: Temperature Within the Benzyl Alcohol Dropletsmentioning

confidence: 99%

Microwave dielectric heating of non-aqueous droplets in a microfluidic device for nanoparticle synthesis

et al. 2013

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We describe a microfluidic device with an integrated microwave heater specifically designed to dielectrically heat non-aqueous droplets using time-varying electrical fields with the frequency range between 700 and 900 MHz. The precise control of frequency, power, temperature and duration of the applied field opens up new vistas for experiments not attainable by conventional microwave heating. We 10 use a non-contact temperature measurement system based on fluorescence to directly determine the temperature inside a single droplet. The maximum temperature achieved of the droplets is 50°C in 15 ms which represents an increase of about 25°C above the base temperature of the continuous phase. In addition we use an infrared camera to monitor the thermal characteristics of the device allowing us to ensure that heating is exclusively due to the dielectric heating and not to other effects like non-dielectric 15 losses due to electrodes or contacts imperfection. This is crucial for illustrating the potential of dielectric heating of benzyl alcohol droplets for the synthesis of metal oxides. We demonstrate the utility of this technology for metal oxide nanoparticle synthesis, achieving crystallization of tungsten oxide nanoparticles and remarkable microstructure, with a reaction time of 64 ms a substantial improvement over conventional heating methods.

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Section: Temperature Within the Benzyl Alcohol Dropletsmentioning

confidence: 99%

Microwave dielectric heating of non-aqueous droplets in a microfluidic device for nanoparticle synthesis

et al. 2013

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“…A single-mode high field-density microwave reactor (2.45 GHz, 850 W) along with internal fiber-optic temperature control had been used in the reactions to monitor the reaction temperature accurately in a small scale(0.5-2 mL) (Obermayer, Gutmann, & Kappe, 2009;Gutmann et al, 2010). Most of the researchers have carried out the microwave-assisted proteomics studies in domestic microwave ovens without reliable reaction temperatures (Vaezzadeh et al, 2010;Hahn et al, 2009;Lesur et al, 2010).…”

Section: Applications In Proteomicsmentioning

confidence: 99%

Microwave Assisted Reactions in Organic Chemistry: A Review of Recent Advances

Jacob¹

2012

IJC

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Revolution in organic compound synthesis has been promoted by microwave assisted organic syntheses (MAOS) by which small molecules are built up into large polymers in a fraction of time. The need for different organic compound libraries for drug discovery, biomaterial development, automated library screening; proteomics etc has supported the emergence of innovative technologies for rapid combinatorial organic synthesis using MAOS synthesis. In previous reviews on this subject the focus of MAOS has been on the process of MAOS reactions rather than the importance given to the related applications. This review focuses on solid-phase synthesis, biopolymer synthesis, applications in proteomics, parallel processing in microwave reactors and automated library generation by means of sequential microwave irradiation methods. This article has discussed the different applications of Microwave assisted synthesis of organic polymeric compounds most thoroughly by focusing on aspects of speed, reproducibility and scalability. From this review it is clearly identified that independent on the type of organic material, data consistently points out to MW as a novel and powerful tool which has enable synthesis of a number of new compounds and presents the need for future research in this area.

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“…50,51 Resta então o aquecimento muito mais rápido na região inteira do recipiente e de forma muito mais eficiente. Um aspecto importante na utilização de micro-ondas é a limitação de escala, o que está sendo superado agora.…”

Section: Micro-ondasunclassified