Nanoparticles in microemulsions

Fig. 13 Synthesis of nanoparticles in microemulsions using a double inverse microemulsions b inverse microemulsion plus a trigger c inverse microemulsion plus reactant [122]...

Fig. 15 Formation of PbS-coated CdS nanocomposite in microemulsion a mixing of a microemulsion containing Cd(N03)2 aqueous solution with a microemulsion containing (NH4)2S aqueous solution b formation of CdS nanoparticle in microemulsion c,d Pb + ions in a third microemulsion replace the Cd + in the Cd-S band and diffuse through the PbS layer to form the PbS shell [142]...

Further examples that deal with the preparation and catalytic activity of unsupported palladium nanoparticles in microemulsion are reported by Spiro de Jesus... 

Chen, J., Wang, X., and Zhang, Z. 2008b. In situ fabrication of mesoporous CdS nanoparticles in microemulsion by gamma ray irradiation. Mater. Lett. 62 787-790. 

A report in the same line [380] involves suspension of ZnS.Mn nanoparticles in microemulsions, with the surface modified by polyoxyethylene(l)laurylether phosphoric acid or polyoxyethylene(4.5)laurylether acetic acid. The coated particles exhibited several times higher photoluminescence intensity and quantum efficiency compared to the uncoated ones. The phosphate group P = O or the carboxyl group C = O, with their luminescent centers, were functional in this improvement, thus opening new routes for imparting superior optical properties on microemulsion-synthesized particles. Gan etaL [376] used four routes for the synthesis of ZnS Mn (i) the relatively new route that involved hydrothermal... 

Santra, S. Tapec, R. Theodoropoulou, N. Dobson, J. Hebard, A. Tan, W. (2001), Synthesis and characterization of silica-coated iron oxide nanoparticles in microemulsion the effect of nonionic surfactants. Langmuir, 17 2900-2906. 

The computer simulation of the formation of nanoparticle in microemulsions was carried out using the model previously reported [7-9]. Briefly, each simulation began with a random... 

Tojo, C., Blanco, M.C., and Lopez-Quintela, M.A. 1997. Preparation of nanoparticles in microemulsions A Monte Carlo study of the influence of the synthesis variables. Langmuir, 13,4527-4534. 

Husein, M., Rodil, E., and Vera, J.H. 2003. Formation of silver chloride nanoparticles in microemulsions by direct precipitation with the surfactant counterion. Langmuir, 19, 8467-8474. 

T1O2 Nanoparticles in Microemulsion Photophysical Properties and Interfacial Electron Transfer Dynamics... 

Optical Absorption and Emission of T1O2 Nanoparticles IN Microemulsion... 

H. N. Ghosh and S. Adhikari, 2001. Trap state emission from Ti02 nanoparticles in microemulsion solutions. Langmuir 17,4129-4130. 

Microemulsions can be considered as true nanoreactors, which can be used to synthesize nanomaterials. The main idea behind this technique is that by appropriate control of the synthesis parameters one can use these nanoreactors to produce tailor-made products down to a nanoscale level Chapter 16 by Tojo and coworkers describes the use of Monte Carlo simulations to study the influence of the critical nucleus size and the chanical reactim rate on the frxmation of nanoparticles in micro-emulsions. Chjpter 17 by Husein and Nassar focuses on exploring ways of maximizing the concentration of stable colloidal nanoparticles, nanoparticle uptake, in single (w/o) microemulsions. Chjpter 18 by Ghosh describes the photophysical and interfacial electron transfer behavior of anatase TrOj nanoparticles in microemulsions. 

In recent years, the use of supercritical solvents has offered a new alternative in the synthesis of nanoparticles in microemulsions which presents several advantages over conventional organic solvents, because their solvation properties can be easily controlled... 

The synthesis of nanoparticles in microemulsions allows one to obtain monodisperse size of the particles and in some cases to control the size of the particles by variation of the size of the microemulsion droplet radius and of the precmsor concentrations. 

In the numerous studies concerning the synthesis of nanoparticles in microemulsion media, the location of water after the nanoparticle synthesis has never been determined. Two models can be proposed (Eig. 13). In the first one the particles are surrounded by a layer of water, and in the second the surfactant molecules (the AOT) are directly adsorbed onto the particles and only a small amount of water molecules is present. 

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