Synthesis polyol process

Li, D.S. and Komarneni, S. (2006) Microwave-assisted polyol process for synthesis of Ni nanoparticles. Journal of the American Ceramic Society, 89 (5), 1510-1517. 

Cheng, W.T. and Cheng, H.W. (2009) Synthesis and characterization of cobalt nano-particles through microwave polyol process. AIChEJournal, 55 (6), 1383-1389. 

Tanase, M. and Laughlin, D. (2004) Polyol process synthesis ofmonodispersed FePt nanoparticles. Journal of Physical Chemistry B, 108 (20), 6121-6123. 

When we consider the metals of nanoscopic size, fine metal particles from micrometer to nanometer size can be synthesized by both physical and chemical methods. The former method provides the fine metal particles by decreasing the size by addition of energy to the bulk metal, while in the latter methods, fine particles can be produced by increasing the size from metal atoms obtained by reduction of metal ions in solution. Since chemical reactions usually take place in homogeneous solution in any case, this chapter includes most of the cases of synthesis and growth of fine metal particles. However, the polyol process, reaction in microemulsions, and formation in the gas phase are omitted, since they are described in later chapters by specialists in those fields. 

Polymer-protected bimetallic clusters were also formed using a modified polyol process. The modification included addition of other solvents and sodium hydroxide. In the synthesis of Co-Ni with average diameters between 150 and 500 nm, PVP and ethylene glycol were mixed with either cobalt or nickel acetate with PVP. The glycol and organic solvents were removed from solution by acetone or filtration. The PVP-covered particles were stable in air for extended periods of time (months). 

A popular method for the synthesis of metal nanowires is the use of the polyol process,lal wherein the metal salt Is reduced in the presence of PVP to yield nanowires of the desired metal. For example, Ag nanowires have been rapidly synthesized using a microwave-assisted polyol method.161 CoNi nanowires are obtained by heterogeneous nucleation in liquid polyol.162 While Bi nanowires have been prepared employing NaBiO, as the bismuth source.161 Pd nanobars are synthesized by varying the type and concentration of reducing agent as well as reaction temperature.1 ... 

Silvert, P., et al. (1996) Preparation of colloidal silver dispersions by the polyol process. Part 1—Synthesis and characterization. J. Mater. Chem. 6 573-577. 

Higher concentrations of bromide result in increased etching and, as mentioned for chloride, the single crystal morphology is preferred. However, unlike with chloride, the nanoparticles formed are not cubes but are elongated into nanorod-like structures, termed nanobars [60]. This is discussed in more detail in Section 11.4 1.3 2, which deals with the synthesis of nanocubes by the polyol process. 

The synthesis of silver nanocubes by the reduction of Ag with glucose in the presence of CTAB has also been reported, see Figure 11.29 [85]. In this synthesis there is no separate seed preparation step. The Ag combines with the Bf of the CTAB to produce AgBr which maintains a low concentration of Ag in solution. During the reaction, single crystal silver seed nanoparticles are formed. The CTAB stabilizes the less stable 100 faces of these, as PVP does in the polyol process, and so nanocubes are the preferred final morphology. 

Sun, Y. and Xia, Y. (2002). Large-scale synthesis of uniform silver nanowires through a soft, self-seeding, polyol process. Adv. Mater. 14 833-837. 

Fievet, F., Polyol Process in T. Sugimoto, Fine Particles Synthesis, Characterization, and Mechanisms of Growth, Marcel Dekker, NY, pp. 460-496, 2000... 

In this work, the novel polyol process was developed to support highly dispersed Pt particles on carbon support with more than 60 wt% in a single reduction step. The synthesis parameters were controlled to optimize the preparation method. Further the continuous polyol process was investigated to obtain an ultra high loading (> 75 wt %), where the reduction steps were repeated two or three times in the polyol process. Thus prepared highly dispersed Pt catalysts were applied to the cathode catalyst of DMFC. The relationship between the structure of R in the catalyst and performance of the DMFC was suggested. 

D. Lewis, R. W. Bruce, S. Gold, A. W. Fliflet, Microwave-Assisted Continous Synthesis of Nanocrystalline Powders and Coatings Using the Polyol Process, Patent Application, Navy Case No. 83,975,2003. 

Fievet F. Polyol process. Sugimoto T, editor. Fine particles, synthesis, characterization and mechanism growth. New York, NY Marcel Dekker 2000. 

The hollow ATO-PANI spheres obtained via the Pickering approach were decorated by Pt nanoparticles using a standardized polyol process. The chosen synthesis protocol for Pt decoration used mild conditions, which hence did not impact the hollow sphere structure. The hollow spheres were then sprayed onto a commercial Nation membrane and applied at the cathode side of an MEA. Figure 7.14a depicts a cross-sectional SEM image of the oxidic hollow spheres. It can be clearly observed that the sphere structure is maintained after the polyol process for Pt decoration. Single cell tests of the novel electrode design showed a maximum power density of 58 mW cm and a platinum utilization... 

Cable R.E., Schaak R.E. Low-temperature solution synthesis of nanocrystalline binary intermetal-lic compounds using the polyol process. Chem. Mater. 2005 17 6835-6841. 

Magnetite particles are quite intriguing, due to their catalytic and magnetic properties strongly dependent on the chosen synthesis method. Several methods are described in the literature, but in the present manuscript we are going to focus on the most common ones iron salts co-precipitation (Massart, 1981 Martinez-Mera et al, 2007), sol-gel reaction, microemulsion (Woo et al., 2003), reaction in mass without solvent (Ye et al., 2006), polyols process (Feldmann Jungk, 2001), decomposition of iron pentacarbonyl (Shafi et al., 2001), etc. 

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