Nanoparticles relation

Okitsu K, Yue A, Tanabe S, Matsumoto H, Yobiko Y, Yoo Y (2002) Sonolytic control of rate of gold(III) reduction and size of formed gold nanoparticles relation between reduction rates and sizes of formed nanoparticles. Bull Chem Soc Jpn 75 2289-2296... 

A considerable amount of development has happened in the last two decades in the area of measurements, dispersion modelling and exposure assessment studies related to airborne nanoparticles. This is clearly evident from the ever-increasing number of published studies in Europe, and elsewhere in general. This study presented PNCs over 45 sampling locations covering about 30 cities and 15 European countries. While reviewing the literature, it was felt that there are still a number of European countries where nanoparticle-related studies are scarce. 

Obradovic MD, Rogan JR, Babic BM, Tripkovic AV, Gautam ARS, Radmilovic VR, Gojkovic SL (2012) Formic acid oxidatitm on Pt-Au nanoparticles relation between the catalyst activity and the poistming rate. J Power Sources 197 72-79... 

Bae E, Park HI, Lee J, Kim Y, Yoon J, Park K, Choi K, Yi J (2010) Bacterial cytotoxicity of the silver nanoparticle related to physicochemical metrics and agglomeration properties. Environ Toxicol Chem 29 2154-2160... 

Incidental nanoparticles are produced as a side product of anthropogenic processes such as in automobile exhausts. One interesting but unexpected source of incidental nanoparticles relates to the discovery that silver and copper metallic nanoparticles are formed spontaneously on the surface of manmade objects (made of Ag and Cu) that humans have long been in contact with and that macroscale objects represent a potential source of nanoparticles in the environment. 

Chapter 1 contains a review of carbon materials, and emphasizes the stmeture and chemical bonding in the various forms of carbon, including the foui" allotropes diamond, graphite, carbynes, and the fullerenes. In addition, amorphous carbon and diamond fihns, carbon nanoparticles, and engineered carbons are discussed. The most recently discovered allotrope of carbon, i.e., the fullerenes, along with carbon nanotubes, are more fully discussed in Chapter 2, where their structure-property relations are reviewed in the context of advanced technologies for carbon based materials. The synthesis, structure, and properties of the fullerenes and... 

In a common method for the production of tubular carbon fibers, the growth is initiated by submicrometer size catalytic metal particles[19]. Tube growth out of a graphite rod during arc-discharge might also be related to nanoparticle-like seeds present... 

In this paper, our present knowledge and understanding with regard to nanoparticles, filled nanocapsules, and the related carbon materials are described. 

The formation of semiconductor nanoparticles and related stmctures exhibiting quantum confinement within LB films has been pmsued vigorously. In 1986, the use of the metal ions in LB films as reactants for the synthesis of nanoscale phases of materials was described [167]. Silver particles, 1-2 mn in size, were produced by the treatment of silver be-henate LB films with hydrazine vapor. The reaction of LB films of metal salts (Cd, Ag, Cu, Zn, Ni, and Pb ) of behenic acid with H2S was mentioned. The use of HCl, HBr, or HI was noted as a route to metal halide particles. In 1988, nanoparticles of CdS in the Q-state size range (below 5 mn) were prepared inside LB films of cadmium arachi-... 

PL spectra of Mn-doped ZnS nanoparticles optically annealai in air (a) and in vacuum (b) are shown in Fig. 2. For Mn-doped ZnS nanoparticles, the PL band is seen at around 585mn. When Mn-doped ZnS nanoparticles were annealed in air, PL intensity is increased more significantly with UV irradiation time compared with ones ann ed in vacuum. PL spectra of Pr-doped ZnS nanoparticles axe shown in Fig. 3. The broad emission at 430 nm corresponds to the emission of the undoped ZnS nanoparticles. The other peak is relaftrii to the Pr-related complexes. The effect of the optical aimealing in air is more notable than in vacuum on the enhancement of luminescent intensity. The incre e of PL intensity for Pr-doped ZnS nanoparticles in mr is more rapid than undoped or Mn-doped ZnS nanoparticles. 

Fig. 4 shows PL spectra of Mn and Pr-codoped ZnS nanoparticles opdcaily aimealed in air and vacuum. Mn and Pr-codoped ZnS nanoparticles emit light of white color. The PL intoisity of the Pr-related peaks incirasrf more rapidly than that of Mn-related peak, for the codoped ZnS nanoparticles ann ed in air. The different rates may be assodated with the luminescent ions. Pr-related oimplaces are incaeased with the incrrasing UV irradiation time, but Mn ions are constant. In case of the arni ing in vacuum, Pr-related peaks are initially weaker in intensity than Mn-related peaks due to small Pr-related complexes. 

Spatially resolved measurements, based on the confocal laser microscope and related techniques, have recently enabled direct detection of individual molecules, single nanoparticles, and molecular assemblies, leading to elucidation of the heterogeneous nature of these systems and its dependence on the individual environments. 

The temperature of investigation is a most important variable. In some cases it is strictly related with the method applied, in others not. In any case, the temperature has a significant influence on the electronic behaviour of a nanoparticle. Usually, investigations at low temperatures allow significantly more detailed answers than those at elevated temperatures. 

The nature of the element under investigation is certainly of some relevance, but not decisive for related elements, say noble metals. On the other hand, it is still not yet known how far the properties of two metal nanoparticles of different elements, but identical size really differ with respect to their quantum size behaviour. 

On the other hand, the XPS data near the Fermi level provide us the valuable information about the band structures of nanoparticles. XPS spectra near the Fermi level of the PVP-protected Pd nanoparticles, Pd-core/ Ni-shell (Ni/Pd = 15/561, 38/561) bimetallic nanoparticles, and bulk Ni powder were investigated by Teranishi et al. [126]. The XPS spectra of the nanoparticles become close to the spectral profile of bulk Ni, as the amount of the deposited Ni increases. The change of the XPS spectrum near the Fermi level, i.e., the density of states, may be related to the variation of the band or molecular orbit structure. Therefore, the band structures of the Pd/Ni nanoparticles at Ni/Pd >38/561 are close to that of the bulk Ni, which greatly influence the magnetic property of the Pd/Ni nanoparticles. 

In Section 2 the general features of the electronic structure of supported metal nanoparticles are reviewed from both experimental and theoretical point of view. Section 3 gives an introduction to sample preparation. In Section 4 the size-dependent electronic properties of silver nanoparticles are presented as an illustrative example, while in Section 5 correlation is sought between the electronic structure and the catalytic properties of gold nanoparticles, with special emphasis on substrate-related issues. 

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