Nanoparticles mobility

Shah D, Maiti P, Jiang D D, Batt C A and Giannelis E P (2005) Effect of nanoparticle mobility on toughness of polymer uaiiocomposites, Adv Mater 17 525-528. 

Fig. 12.13 High-resolution TEM images resulting from phase contrast (with increasing exposure time), showing the Au nanoparticle mobility and coalescence effects induced by the energy of the incident beam in the material. Acquiring the first image for the third (from left to right), the elapsed time was 1 min (Pyrz Butlrey Langmuir. 2008 24 11350-60 (Adapted with permission) [27]...

From a structural point-of-view the bulk metallic state, that is, fee lattice (with varying densities of defects such as twins and stacking faults) is generally established in gold nanoparticles of about 10 nm diameter and upwards. However, such particles still display many unusual physical properties, primarily as the result of their small size. Shrinking the size of gold particles has an important effect it increases both the relative proportion of surface atoms and of atoms of even lower coordination number, such as edge atoms [49] and these atoms in turn are relatively mobile and reactive. 

An LCD is a ubiquitous electronic display. Now, it is widely distributed among human daily life, like mobile phones, TV, and personal computers. The LCD has, however, a drawback, i.e., slower response than a plasma display or an electroluminescene display. Recently we have first succeeded in combination of a nanoparticle technology with the LCD technology, which realized fast response of the LCD [45,235,236]. Thus we have found a phenomenon, i.e., a frequency modulation of the LCD doped with metallic nanoparticles. Since the frequency modulation, or electro-optic property depends on the kind of metals, we have prepared AgPd bimetallic nanoparticles protected with a typical liquid crystal molecule, 4-cyano-4 -pentylbiphenyl (5CB) to investigate the electro-optic property [45,235,236]. 

Maillard F, Fikerling M, Cherstiouk OV, Schreier S, Savinova FR, Stimnting U. 2004a. Size effects on reactivity of Pt nanoparticles in CO monolayer oxidation The role of surface mobility. Faraday Discuss 125 357-377. 

Figure 15.4 Schematic representation of the Langmuir-Hinshelwood reaction between two adsorbates mobile X (black) and immobile Y (white) on a stepped single-crystalline surface (a) and a facetted nanoparticle (b).

In summary such marked structural differences can be assumed to affect the structure of the initial nanoparticles in the solidification process. Improved peak resolution, deconvolution, Q1 ratio-possible ring structure matching, model calculations, and comparison with NMR and other structural data can make Raman a quite useful, inexpensive, and mobile accessory for studying the structure of silicates both in aqueous solutions and in solid phase. 

Such a hindered mobility would prevent Zr02 nanoparticles from self-aggregating in the state of sol and allow for migration from the core to the surface of condensing (shrinking) silica at high temperatures. 

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