Gold, colloidal Faraday

While the chemical properties of GNPs were first studied by Faraday, the main application of gold colloids in the biomedical field has been related to their electronic and optical properties [8, 9]. At present, there are many synthetic routes to... 

Turkevich, J., Stevenson, P. and Hillier, J. (1951) A study of the nucleation and growth processes in the synthesis of colloidal gold. Discuss. Faraday Soc. 11, 55-59... 

Historically, Michael Faraday must be credited with some of the earliest work on small particles, his gold colloid preparations are still used today over 200 years later. In 1925, Richard Zsigmondy received the Nobel Prize for his study of colloidal metal solutions. Today microclusters of metals constitute one of the most important of man s synthetic materials they are vital in heterogeneous catalysis on which 20% of the GNP of the United States is dependent. Among other numerous applications of small metal particles are thin films and coatings, latent image development, and photographic films. 

Faraday was the first to report what are now described as nanoparticles. He noted in 1847 that properties of gold colloids (clusters ) differed from those of the bulk metal. This might be considered to be the birth of nanoscience. Gold atom aggregates are prominent among metal clusters of current interest. 

The first scientific study of metal nanoparticles is dated back to the seminal work of Michael Faraday around 1850 [14]. Faraday was the first to notice that the red colour of gold colloid was due to the minute size of the Au particles and that one could turn the preparation blue by adding salt to the solution. He was able to obtain gold colloids reducing Audi by phosphorus, following a procedure already reported by Paracelsus in 16 century about the preparation of Aurum Potabile and based on a two phase water / CS2 reaction. It is to be noted that some of Michael Faraday s preparations are still preserved today in the Faraday Museum in London [15]. 

FIGURE 8.45 The stability of colloids is illustrated by this violet liquid, which is a colloid of metallic gold that has survived since it was prepared by Michael Faraday in 1857... 

The topic of gold nanospheres attracted the interest of several famous nineteenth century scientists such as Michael Faraday, Richard Zsigmondy, and Gustov Mie [43]. Interest diminished in the mid-twentieth century although some excellent contributions were made by Turkevich [42, 44], Frens [45], and Brust [46] in that period regarding the controlled preparation of nearly monodisperse colloidal suspensions. 

This relationship permits of experimental verification by direct observation of the diffusion coefficient and the measurement of the radius of the particle. Svedberg Zeit. Phys. Chem. LXVII. 105, 1907 Archiv f Kemi, etc., K. Svmska Vetensk. Akad. Stockholm, B, IV. 12,1911) employed colloidal gold prepared by reduction with phosphorus according to the directions of Faraday and Zsigmondy. 

British scientist Michael Faraday (1791-1867) experiments with colloidal gold—a suspension of extremely small gold particles in a liquid. These... 

It took almost a century from the time Faraday obtained the first monodispersed colloid, his well-known gold sol (22), until the works of Steele (l) and Heller (2,3) mentioned earlier. Therefore, it is even more surprising that all one needs to obtain... 

Faraday prepared a colloidal dispersion of gold fine particles by reduction of gold(lll) ions with white phosphorus. Recently, Turkevich prepared the gold sol by reduction... 

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