Charge static redistribution

Such a charge static redistribution due to the deposition of an adsorbate on the particle surface and the respective change in the electron concentration in the MNPs were also observed in the SPR absorption spectra [2, 59]. In metals (silver, sodium, aluminum, etc.), where free conduction electrons dominate, the SPR spectral maximum depends on the concentrations of electrons, N, in nanoparticles as... 

In this chapter, we studied the formation of silver nanoparticles in PMMA by ion implantation and optical density spectra associated with the SPR effect in the particles. Ion implantation into polymers carbonizes the surface layer irradiated. Based on the Mie classical electrodynamic theory, optical extinction spectra for silver nanoparticles in the polymeric or carbon environment, as well as for sheathed particles (silver core -l- carbon sheath) placed in PMMA, as a function of the implantation dose are simulated. The analytical and experimental spectra are in qualitative agreement. At low doses, simple monatomic silver particles are produced at higher doses, sheathed particles appear. The quantitative discrepancy between the experimental spectra and analytical spectra obtained in terms of the Mie theory is explained by the fact that the Mie theory disregards the charge static and dynamic redistributions at the particle-matrix interface. The influence of the charge redistribution on the experimental optical spectra taken from the silver-polymer composite at high doses, which cause the carbonization of the irradiated polymer, is discussed. Table 8.1, which summarizes available data for ion synthesis of MNPs in a polymeric matrix, and the references cited therein may be helpful in practice. 

When analyzing the optical properties of nanoparticles embedded in a medium, one should take into account effects arising at the particle-matrix interface, such as the static and dynamic redistributions of charges between electronic states in the particles and the environment in view of their chemical constitution [59]. 

The more advanced, dsmamic coordination or functional approach considers the solute-solvent or ion-solvent interactions as a result of electron pair donor-acceptor interactions, and inductive and mesomeric effects. According to this theory, the equihbriiun between nonionized species and solvent-separated ion pairs is a function of the dsmamic electron pair acceptor and donor properties of the solvent, not simply their static polarity (73,74). Ionization may be affected by a nucleophilic attack of a donor (D) or by an electrophilic attack of an acceptor (A) directed to the substrate R—Y. The strong donor-acceptor interactions first lead to charge redistribution between and within the molecules (pile-up and spillover effects), and ultimately to the heterolytic scission of the covalent R—Y bond (eq. 8) ... 

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