Second generation spherical particles

Fullerenes and carbon onions can be produced by various processes [2-6]. TEM pictures show a wide shape diversity of these particles polyhedral, spherical, highly defected fullerenes with various sizes and number of layers. The spherical structures may contain many defects like (Stone-Wales [7]). In this study we deal with icosahedral regular fullerenes [8] and with very Stone-Wales defective structures that lead to spherical particles [9]. These structures have been optimized with second-generation reactive empirical bond order potential energy (REBO2) [10]. The static dielectric properties are calculated using the RMD... 

The first of these asymptotic expressions corresponds to an outgoing spherical wave the second corresponds to an incoming spherical wave. If, on physical grounds, the scattered field is to be an outgoing wave at large distances from the particle, then only should be used in the generating functions. When we consider the scattered field at large distances we shall also need the asymptotic expression for the derivative of h it follows from the identity... 

The trajectories of the M reflected fictitious particles are further generated by means of Eqs. [43] and [44] until either (i) the particle collides again with the reflecting spherical surface or (ii) the particle escapes the potential well (Region II) and enters region I. If the fictitious particle is incident upon the reflecting surface for the second time (i.e., event (i) as described above), as explained earlier, a coagulation event has occurred. 

Synthesis of a new modification of silica soluble in THF is described. At the first synthetic step, a hyperbranched polyethoxysiloxane (HBPES) is synthesized by heterofunctional condensation using triethoxysilanol previously generated in reaction mixture by neutralization of correspondent sodium salt with acetic acid. At this step, the process was monitored by IR spectroscopy, SEC, and Si NMR spectroscopy. At the second step, hydrolysis and intramolecular condensation involving silanol groups is carried out to yield silica sol macromolecules. A SAXS method was used to determine the size and fractal coefficient of trimethylsilated derivatives and silica sols obtained. An atomic-force microscopy imaging of silica sol supported on a mica substrate showed the silica sol particles to be predominantly spherical in shape. Prospects for theoretical, experimental and practical applications of silica sols are discussed. 

In the second chapter (Preparation of polymer-based nanomaterials), we summarize and discuss the literature data concerning of polymer and polymer particle preparations. This includes the description of mechanism of the radical polymerization of unsaturated monomers by which polymer (latexes) dispersions are generated. The mechanism of polymer particles (latexes) formation is both a science and an art. A science is expressed by the kinetic processes of the free radical-initiated polymerization of unsaturated monomers in the multiphase systems. It is an art in that way that the recipes containing monomer, water, emulsifier, initiator and additives give rise to the polymer particles with the different shapes, sizes and composition. The spherical shape of polymer particles and the uniformity of their size distribution are reviewed. The reaction mechanisms of polymer particle preparation in the micellar systems such as emulsion, miniemulsion and microemulsion polymerizations are described. The short section on radical polymerization mechanism is included. Furthermore, the formation of larger sized monodisperse polymer particles by the dispersion polymerization is reviewed as well as the assembling phenomena of polymer nanoparticles. 

---