Solid-solvent interface

Although there are analogies between solidification and crystallization, there are also some important structural differences between the solid-melt interface (also called the solidification front) and the solid-solvent interface due to the differing concentration, viscosity, and temperature of the respective liquid phase. These may be summarized as follows ... 

The degree of solution agitation is logically expected to influence saturation level at solid-solvent interface of the nuclei as well as bring about temperature drop in the system. This is probably the reason for the... 

Having defined impregnation, it remains to specify what drying is, or, more precisely, when drying stops and calcination starts, as far as thermal treatments are concerned. In this chapter, drying will be considered as the thermally activated step during which the solvent, submitted to evaporation and still present in its molecular form, is able to influence the transport of its chemical partners or to react with them. Calcination concerns a system in which the solid/solvent interface has been replaced by a solid/gas interface, on which new transformations take place (decomposition of ligands, ion diffusion, etc.). 

T. Cosgrove, T. G. Heath, B. van Lent, and J.M.H.M. Scheutjens, Configuration of terminally attached chains at the solid/solvent interface Self-consistent field theory and Monte Carlo model. Macromolecules 20, 1692 (1987). 

III.1. Polymer Depletion at the Solid/Solvent Interface (Fig. 5) With... 

Many important processes such as electrochemical reactions, biological processes and corrosion take place at solid/liquid interfaces. To understand precisely the mechanism of these processes at solid/liquid interfaces, information on the structures of molecules at the electrode/electrolyte interface, including short-lived intermediates and solvent, is essential. Determination of the interfacial structures of the intermediate and solvent is, however, difficult by conventional surface vibrational techniques because the number of molecules at the interfaces is far less than the number of bulk molecules. 

Chandra and his coworkers have developed analytical theories to predict and explain the interfacial solvation dynamics. For example, Chandra et al. [61] have developed a time-dependent density functional theory to predict polarization relaxation at the solid-liquid interface. They find that the interfacial molecules relax more slowly than does the bulk and that the rate of relaxation changes nonmonotonically with distance from the interface They attribute the changing relaxation rate to the presence of distinct solvent layers at the interface. Senapati and Chandra have applied theories of solvents at interfaces to a range of model systems [62-64]. 

The effect of polymorphism becomes especially critical on solubility since the rate of compound dissolution must also be dictated by the balance of attractive and disruptive forces existing at the crystal-solvent interface. A solid having a higher lattice free energy (i.e., a less stable polymorph) will tend to dissolve faster, since the release of a higher amount of stored lattice free energy will... 

Electroosmosis or electroendosmosis is the bulk movement of the solvent (electrolyte solution) in the capillary caused by the zeta (0 potential at the wall/water interface of the capillary. Any solid-liquid interface is surrounded by solvent and solute constituents that are oriented differently compared to the bulk solution. Figure 17.2 illustrates a model of the wall-solution interface of the widely applied capillaries. Owing to the nature of the surface functional groups, in silica capillaries the silanol groups, the solid surface has an excess of negative... 

The lithium-storage properties of these Si SiOx/C nanocomposite electrodes were investigated in different electrolyte systems and compared to pure Si nanoparticles. From all the analyzed systems, the Si SiOx-C nanocomposite in conjunction with the solvent vinylene carbonate (VC) to form the solid-electrolyte interface showed the best lithium storage performance in terms of a highly reversible lithium-storage capacity (1100 mAh g-1), excellent cycling performance, and high rate capability (Fig. 7.9). 

Fruitful interplay between experiment and theory has led to an increasingly detailed understanding of equilibrium and dynamic solvation properties in bulk solution. However, applying these ideas to solvent-solute and surface-solute interactions at interfaces is not straightforward due to the inherent anisotropic, short-range forces found in these environments. Our research will examine how different solvents and substrates conspire to alter solution-phase surface chemistry from the bulk solution limit. In particular, we intend to determine systematically and quantitatively the origins of interfacial polarity at solid-liquid interfaces as well as identify how surface-induced polar ordering... 

One aspect of the research will examine equilibrium aspects of solvation at hydro-phobic and hydrophilic interfaces. In these experiments, solvent dependent shifts in chromophore absorption spectra will be used to infer interfacial polarity. Preliminary results from these studies are presented. The polarity of solid-liquid interfaces arises from a complicated balance of anisotropic, intermolecular forces. It is hoped that results from these studies can aid in developing a general, predictive understanding of dielectric properties in inhomogeneous environments. 

Complementing the equilibrium measurements will be a series of time resolved studies. Dynamics experiments will measure solvent relaxation rates around chromophores adsorbed to different solid-liquid interfaces. Interfacial solvation dynamics will be compared to their bulk solution limits, and efforts to correlate the polar order found at liquid surfaces with interfacial mobility will be made. Experiments will test existing theories about surface solvation at hydrophobic and hydrophilic boundaries as well as recent models of dielectric friction at interfaces. Of particular interest is whether or not strong dipole-dipole forces at surfaces induce solid-like structure in an adjacent solvent. If so, then these interactions will have profound effects on interpretations of interfacial surface chemistry and relaxation. 

Organizational characteristics of surface-active molecules have been studied by several researchers due to their applications in many areas such as personal care, polymerization, catalysis, drug delivery, separation and purification, enhanced oil recovery and lubrication. The structure of supramolecular organized assemblies formed in different solvents, when a critical concentration is exceeded, determines their properties such as solubilization [1-3], catalysis [1,4-6], adsorption [7-11] and flocculation [12,13]. As such, many techniques have been used to determine their structural properties. In this paper, the results obtained using fluorescence probing for properties of assemblies in solution and at solid-liquid interfaces are discussed in detail after a brief review of relevant assemblies formed by them. 

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