Nanoparticle morphology/shape

Many different topics are involved in the study of metallic nanoparticles and many fundamental issues can be present for example, which is the infiuence of the nanoparticle size, shape and composition on the chemical activity of heterogeneous catalysts Or, considering another problem, at what size does a small particle behave like the bulk material, for example, changing from an insulator to a semiconductor [9-12] An enormous amount of literature is published on metallic nanoclusters this review is focusing on the relevant problem concerning the characterization of metallic nanosized materials from the morphological and... 

Figure 8.8 Effect of nanoparticle precursor shape on morphology (colloidal vs. polymeric) and strength of the gel network generated by oxidative treatment of thiolate-capped CdSe nano-particles with tetranitromethane. Note that the nanodot gels undergo s3meresis and contract during aging, whereas the nanorod gels are firm, take the shape of their container, and can be inverted. (Reproduced with permission from H. Yu et al., J. Am. Chem. Soc. 2008, 130, 5054. Copyright 2008 American Chemical Society.)...

The control of nanoparticle morphology becomes a very important aspect, since morphology profoundly influences the material performance. As a longterm goal the development of synthesis schemes able to control particle size, shapes, and composition independently from one another is very important, in order to allow tuning of nanocomposite properties. 

Table 1 provides a siunmaiy of the wealth of experimental techniques utilized in the study of catalysts, which allow for the investigation of nanoparticle morphology, nanoparticle shape and / or adsorption at the atomic level. 

These relationships are particularly significant in micro- and nanofluidics as well as in other aspects of polymer rheology. Although recent advances in the development of colloidal dispersions at sub-nano-diameter levels are promising, colloidal nanoparticles with versatile morphologies, shapes, and bioactive attributes are of particular interest. 

The intensity, number, and width of the surface plasmon resonances are very sensitive to the nanoparticle morphology. For metal nanoparticles whose shape deviates from that of a sphere, exact analj ic solutions of the extinction cross section are not available. Here we will describe, examples of absorption and scattering spectra obtained by discretizing the targets within the DDA framework... 

But the chemical reactions provide only half of the information on the way to establishing a complete nanoparticle formation mechanism. The other half includes all types of crystallization processes such as prenucleation, nucleation and growth, and assembly and agglomeration. Size, shape, and size distribution of the nanoparticles are strongly dominated by crystallization processes. The tremendous variety of nanoparticle morphologies and architectures made it necessary to expand classical crystallization theory to new concepts such as oriented attachment, particle-based crystallization, or mesocrystal formation [154]. 

This species has been used as precursor of nanogold particles by electrodeposition. When the electrodeposition is induced from the isotropic state at 117 °C, the nanoparticles obtained are nanodots aggregated in a spherical-like shape. In contrast, the morphology of the nano particles prepared from the SmA mesophase at 111 °C consist of leaf-like forms interlocked in rosettes. 

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