Microemulsion-microwave synthesis

The chemical methods have been used for the synthesis of bismuth nanoparticles by vapor flow condensation [6] and microemulsion process [7]. It is generally accepted that the microwave synthesis and sintering (MS) processes [8-10] can concentrate ceramic materials at a very rapid rate and at a substantially lower temperature than the conventional sintering (CS) process. 

Liquid-phase synthesis takes place in the following synthetic approaches (1) coprecipitation, (2) sol-gel, (3) microemulsion, (4) hydrothermal/solvothermal synthesis, (5) microwave synthesis, (6) sonochemical synthesis, (7) template synthesis, and (8) biometric synthesis. 

Recent scientific literature demonstrates a growing interest in new methods of nanoparticle synthesis, driven primarily by an ever-increasing awareness of the unique properties and technological importance of nanostructured materials. The fabrication of nanoparticles within reverse microemulsions [40, 146] has been shown to be a convenient route to monodisperse particles of controllable size. A recognised goal of these synthetic approaches is to achieve control over the composition, size, surface species, solubility, stability, isolability and other functional properties of the nanostructures. The combination of reverse microemulsion and microwave heating has the added advantage that the oil phase in the reverse microemulsion system is transparent to microwave so that the aqueous domains are heated directly, selectively and rapidly. 

Esterification. The lipase-mediated esterification is promoted by microwave (90°, 15 min.). Four lipases immobilized in microemulsion-based gels retain their activity in catalyzing esterification. Resolution by selective acetylation of ethyl 6-hydroxy-1-cyclohexenecarboxylate gives access to a chiral intermediate for a synthesis of the spirocyclic alkaloids (+)-nitramine, (+)-isonitramine, and (-)-sibirine. 

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