Metallic nanoparticles history

Colloidal dispersions of fine metal particles have a long history. Metal nanoparticles are now in the spotlight because of recent developments in nanometer-scale science and technology. Especially the precise structure of the monodispersed bimetallic nanoparticles has become clear quite recently, thanks to the development of EXAFS technology. The mechanism of formation, growth, and structure control is not completely clear yet. In some parts, especially in Section 9.1.4, the discussion may be speculative but is based on the experience of the present author for over 20 years. 

Intrinsic approaches focus on the detection of trace of chemicals and molecules with unique Raman spectra that are small enough to bind at SERS hot spots such as tips and crevices of metal nanoparticles. Direct measurement of small chemicals has a long history in SERS. The SERS phenomenon itself was discovered by the measurement of pyridine molecules adsorbed to a silver electrode that had been electro-chemically roughened to increase the surface area and therefore the signal [16]. 

The studies of metal-dielectric nanocomposites and methods of their manufacture also have a long history (see review [1]). Recently, the technological progress has ensured the development of a wide collection of new methods and techniques suitable for production of nanoparticles and nanomaterials, including nanocomposites. It is possible to classify these methods as the following ... 

One of synthetic approaches for the iron nanoparticles is based on the widely used decomposition of iron pentacarbonyl [19, 361, 362], The novelty of the approach is the surfactant system used. Studies with a number of strongly bound surfactants have resulted in decreased magnetic response, due to surface oxidation, disturbing the electronic structure of the surface atoms, or some other mechanism. With this in mind, ones chose to work with a weak surfactant, a p-diketone. P-diketones do have a history as adhesion promoters in bonds between metals and polymers [363], The limited reactivity of p-diketones is as an advantage the P-diketone is much weaker oxidizer than carboxylic acids or alcohols and will not oxidize iron, it is not as nucleophilic as phosphines, yet it is known to be capable of chelating iron. 

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