Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Self-affine structure

Within the frameworks of this formalism to account for consistently nonlinear phenomenon complex nature is a success, such as memory effects and spatial correlations. In addition the earlier known solutions are not only reproduced, but their nontrivial generalization is given. Another important feature is connected with fractal structures self-similarity using. Unlike the traditional methods of system description on the basis of averaging different procedures, when microscopic level erasing occurs, in fractal conception medium self-affine structure and thus within the frameworks of this conception system micro and macroscopic description levels are united. Exactly such method is important for complex multicomponent systems, discovered far from thermodynamic equilibrium state [35], which are polymers [12], The authors of Refs. [31, 32] are attempted two indicated trends combination. [Pg.278]

The structure of this review is composed of as follows in Section II, the scaling properties and the dimensions of selfsimilar and self-affine fractals are briefly summarized. The physical and electrochemical methods required for the determination of the surface fractal dimension of rough surfaces and interfaces are introduced and we discuss the kind of scaling property the resulting fractal dimension represents in Section III. [Pg.349]

Otsuka and Iwasald [16] have employed AFM method to observe the self-affine fractal structure of the electrochemically roughened Ag electrode surfaces [17]. Later, they have described the dynamic scaling in recrystallization of this electrode surface in water. [Pg.917]

Electric Double Layer and Fractal Structure of Surface Electrochemical impedance spectroscopy (EIS) in a sufficiently broad frequency range is a method well suited for the determination of equilibrium and kinetic parameters (faradaic or non-faradaic) at a given applied potential. The main difficulty in the analysis of impedance spectra of solid electrodes is the frequency dispersion of the impedance values, referred to the constant phase or fractal behavior and modeled in the equivalent circuit by the so-called constant phase element (CPE) [5,15,16, 22, 35, 36]. The frequency dependence is usually attributed to the geometrical nonuniformity and the roughness of PC surfaces having fractal nature with so-called selfsimilarity or self-affinity of the structure resulting in an unusual fractal dimension... [Pg.201]

Quantitatively, a self-afRne fractal is defined by the fact that a change Ax XAx (and possibly Ay —> XAy) transforms Az into X Az, where H lies between 0 and 1. The case H — 1 corresponds to a self-similar fractal. Self-affine fractal structures are no longer characterised by just one (mass or boundary) fractal dimension they require two. The first is local and can be determined by the box-counting method, for example it describes the local scale invariance and its value lies between 1 and 2. The second is global and its value is a simple whole number describing the asymptotic behaviour of the fractal. In the case of a mountain, this global dimension is simply 2. When viewed from a satellite, even the Himalayas blend into the surface of the Earth. [Pg.60]

We have discussed the self-assembly of nonionic surfactants that occurs in RTILs. Overall, the self-assembly properties in RTILs are largely similar to the aqueous medium. Notable differences between the aqueous and nonaqueous systems are sometimes seen when nonionic surfactants form micelles or lyotropic liquid crystals at certain compositions and temperatures, and this mainly results from the different affinity of the nonionic surfactants with the liquids. In other words, it may be possible to expect the formation of micelles or lyotropic liquid crystals to a certain degree by considering the solvophobic or solvophilic nature of the nonionic surfactants in the RTILs. An interesting feature of RTILs is their self-assembly in bulk liquids and at interfaces. This feature also makes a significant impact on the self-assembly of nonionic surfactants in RTILs. Particularly, we have demonstrated the importance of this feature when nonionic surfactants adsorb at solid/RTIL interfaces. We believe that the self-assembled structures of amphiphilic molecules with RTILs are of great interest not only from academic but also from industrial standpoints. One of the potential applications based on such self-assembled structures should be high-performance ion-conductive electrolytes as a new device system with nanolevel order [50]. [Pg.59]

Avram L, Cohen Y (2004) Self-recognition, structure, stability, and guest affinity of pyrogallol[4] arene and resorcin[4]aiene capsules in solution. J Am Chem Soc 125 11556-11562... [Pg.255]

Film surface areas as a probe for of surface fractal dimension agree with previous SAXS and molecular tiling results for materials which are not self-affine. Pore size distributions calculated via film surface areas seem to provide reasonable results in the microporous region although the method should always underestimate pore size and pore volume but a correction could be developed for this systematic deviation. However, because of the sensitivity of vapor volume uptake to P/Po/ this method should not be used for mesopores. A more rigorous test of the film surface area PSD method awaits results for solids with better described pore structure such as zeolites. REFERENCES... [Pg.188]


See other pages where Self-affine structure is mentioned: [Pg.88]    [Pg.390]    [Pg.453]    [Pg.1056]    [Pg.150]    [Pg.88]    [Pg.390]    [Pg.453]    [Pg.1056]    [Pg.150]    [Pg.98]    [Pg.106]    [Pg.52]    [Pg.383]    [Pg.355]    [Pg.389]    [Pg.418]    [Pg.452]    [Pg.197]    [Pg.17]    [Pg.151]    [Pg.345]    [Pg.170]    [Pg.186]    [Pg.207]    [Pg.64]    [Pg.30]    [Pg.5]    [Pg.7261]    [Pg.887]    [Pg.162]    [Pg.427]    [Pg.193]    [Pg.163]    [Pg.13]    [Pg.366]    [Pg.217]    [Pg.217]    [Pg.1282]    [Pg.199]   
See also in sourсe #XX -- [ Pg.278 ]




SEARCH



Self structures

Self-affinity

© 2024 chempedia.info