Sonochemical coprecipitation

COP = coprecipitation SC = sonochemical Ac = acetate acac = acetylacetonate AOT = bis(2-ethylhexyl) sodium sulfosuccinate BA = benzyl alcohol ... 

The fifth chapter presents detailed review of technological aspects of ferroic nanoparticles fabrication. We present the detailed information about methods of chemical synthesis of above nanoparticles. Among them are hydrothermal, sol-gel and coprecipitation methods. We also present the method of unstable compounds decomposition. The combined synthesis methods have also been discussed. Namely, we consider mechanochemical, sonochemical and template synthesis methods. The main idea of these methods is to control the dispersity and agglomeration degree of nanoparticles by inspection of nucleation and growth of a new phase. Self-assembly and self-organization of ferroic nanoparticles as well as composites formation on their base by means of colloidal processes have also been considered. 

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. 

The synthesis of colloidal paramagnetic nanoparticles is a complex process. The requirements of the produced magnetic nanoparticles are homogeneous composition, narrow size distribution, and repeatable and facile chemical conditions. Magnetic nanoparticles can be synthesized by numerous chemical methods such as microemulsions [113], sol-gel synthesis [114], sonochemical reactions [115], hydrothermal reactions [116], hydrolysis and thermolysis of precursors [117], flow injection syntheses [118], electrospray syntheses [119], and the most commonly used technique chemical coprecipitation of iron salts [120,121],... 

The preparation of nanomaterials is one of the most active fields in material science. Number of techniques have been used for the production of nanoparticles gas-evaporation [11], sputtering [12], sol-gel method [13], hydrothermal [14], microemulsion [15, 16], polyols [17], laser pyrolysis [18], sonochemical synthesis [19], chemical coprecipitation [20-22], and so on. Among them, the surfactant assembly mediated synthesis is attracting more attention because it allows for a good... 

Fes04 nanoparticles are commonly produced via coprecipitation of ferrous (Fe ) and ferric (Fe ) ions by a base, usually NaOH, or NH3, in an aqueous solution [348], or they may be made by thermal decomposition of alkaline solution of Fe chelate in the presence of hydrazine [349] and by sonochemical decomposition of hydrolyzed Fe(II) salt followed by thermal treatment [350]. The disadvantage of these aqueous solution syntheses is that the pH value of the reaction mixture has to be adjusted in both the synthesis and purification steps, and the process toward smaller (<20 nm) monodisperse nanoparticles has only very limited success. 

Synthetic methods of preparing materials are broadly divided into two categories physical and chemical methods, and include coprecipitation, hydrothermal and solvothermal, sol-gel, microemulsion, microwave, sonochemical, impregnation, combustion, ball milling and so on. There are several parameters, which influence the size and morphology of the finished material.By controlling these parameters it is possible to make well-defined ceria-based oxides as shown in Fig. 8.1. 

This method was used for the preparation of nanoparticles with high surface energy and chemical activity. In this procedure sol gel process, coprecipitation, micellar nanoreactor, hydrothermal synthesis, sonochemically and/or microwave and combustion synthesis have been included [39]... 

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