Nanostructured materials ultrasound

Ultrasonic irradiation of a liquid leads to the generation of cavitation phenomenon which comprised of unique reaction fields in addition to physical and mechanical effects the formation of micro-meter sized bubbles, formation of bubbles with high temperature and high pressure conditions, formation of shock waves, and strong micro-stirring effects are produced. Table 5.1 shows representative ultrasound techniques to synthesize inorganic and metal nanoparticles and nanostructured materials. 

Table 5.1 Representative ultrasound techniques to synthesize inorganic and metal nanoparticles and nanostructured materials...

Suslick KS, Hyeon T, Fang M (1996) Nanostructured materials generated by high-intensity ultrasound sonochemical synthesis and catalytic studies. Chem Mater 8 2172-2179... 

High power ultrasound applied to an alkoxide/water mixture makes it possible to obtain nanostructured materials. The process is driven by the acoustic cavitation phenomenon. The cavities act as nanoreactors, where the hydrolysis reaction starts. The products (alcohol, water, and silanol) help continue the dissolution of that immiscible mixture. 

Ultrasonication is an important method in the preparation of nanostructured materials (Bang and Suslick 2010), and it may be mild when performed on an ultrasound bath, or severe when performed in an ultrasonic processor (ultrasonic probe). The main effect of ultrasound is the cavitation, which consists of a cycle of... 

Abstract In the last decade, the sonoelectrochemical synthesis of inorganic materials has experienced an important development motivated by the emerging interest in the nanostructures production. However, other traditional sonoelectrochemical synthesis such as gas production, metal deposits and metallic oxide films have also been improved with the simultaneous application of both electric and ultrasound fields. In this chapter, a summary of the fundamental basis, experimental set-up and different applications found in literature are reported, giving the reader a general approach to this branch of Applied Sonoelectrochemistry. 

H. Zhou et al. [6] developed a novel bacteria-templated sonochemical route for the controllable assembly of ZnS nanoparticles into desired hollow nanostructures. It is based on artificial mineralization and cell disruption under ultrasound. Two shapes of bacteria cocci and bacillus were used as templates to direct the formation of corresponding ZnS hollow spheres and hollow nanotubes, respectively. The inorganic replicas retain the original morphologies of the templates faithfully. This bacteria-templated sonochemical method can be extended to the synthesis of various ZnS hollow assemblies by templating other shapes of bacterium such as vibrios, spirillum, square bacteria, etc. Meanwhile, this method is expected to be a generic means to the siiiple synthesis of hollow assemblies of various materials. 

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