Interface textures

Early (1930 to 1940) kinetic studies of dehydrations contributed much to the development of the concept of the reaction interface as the important feature of nucleation and growth reactions [2]. Kinetic equations applicable to the decompositions of a vnde range of crystalline substances were developed. Large, well-formed crystals of hydrates could be prepared relatively easily and studies of these were particularly rewarding. The interpretation of kinetic data was supplemented by microscopic evidence concerning the formation and development of product nuclei. Recent work on dehydrations has included more precise determinations of the crystal structures of reactants, products and their interrelationships, including interface textures, in the attempt to resolve unanswered questions. 

A more detailed examination of the intranuclear channel structures and interface textures developed during these reactions demonstrated that no detectable cracking penetrated the reactant in advance of the reactant/product contact [107], This is consistent with the above conclusions. No considerable strain is associated with the interface, so that reaction is not a consequence of water loss at surfaces exposed following crack propagation through stress relief in the vicinity of and associated with the phase transition. 

The surface of PSs is determined as an interface between the condensed phase and the space of the pores. For catalysts with supported active components textural characteristics of individual phases are important, including their accessible, surface areas and the interfacial surface areas [5,6],... 

The classical Kelvin equation assumes that the surface tension can be defined and that the gas phase is ideal. This is accurate for mesopores, but fails if appUed to pores of narrow width. Stronger sohd-fluid attractive forces enhance adsorption in narrow pores. Simulation studies [86] suggest that the lower limit of pore sizes determined from classical thermodynamic analysis methods hes at about 15 nm. Correction of the Kelvin equation does lower this border to about 2 run, but finally also the texture of the fluid becomes so pronounced, that the concept of a smooth hquid-vapor interface cannot accurately be applied. Therefore, analysis based on the Kelvin equation is not applicable for micropores and different theories have to be applied for the different ranges of pore sizes. 

Giannakas, AE Vaimakis, TC Ladavos, AK Trikalitis, PN Pomonis, PJ. Variation of surface properties and textural features of spinel ZnAl204 and perovskite LaMnOs nanoparticles prepared via CTAB-butanol-octane-nitrate salt microemulsions in the reverse and bicontinuous states. Journal of Colloid end Interface Science, 2003, Volume 259, Issue 2, 244-253. 

The dry nematic solution exhibits a smooth texture after being annealed, with a field of disclinations at any glass-solution interface. A nematic phase produced by cooling the isotropic phase will exhibit a complex, mottled texture that slowly anneals to the smooth texture. The ratio Rvv(q)/ Hv(q) (for e = 20 deg.) for either morphology indicates appreciable orientational averaging of the orientation fluctuation. Photon correlation scattering on the... 

Spherical droplet that forms during a transition from an isotropic phase to a nematic mesophase. It has characteristic textures that depend on the droplet size and the director orientation at the nematic-isotropic interface. 

Note 3 A bipolar droplet texture occurs when the director lies in the plane of a nematic-isotropic interface. 

Gomez-Villacieros, R. Hernan, L. Morales, J. Tirado, J.L. (1984) Textural evolution of synthetic y-FeOOH during thermal treatment by differential scanning calorimetry. J. Colloid Interface Sci. 101 392-400... 

Kandori, K. Tamura, S. Ishikawa.T. (1994) Inner structure and properties of diamondshaped and spherical a-Fe203 particles. Colloid Polym. Sci. 272 812-819 Kandori, K. Uchida, S. Kataoka, S. Ishikawa, T. (1992) Effects of silicate and phosphate on the formation of ferric oxide hydroxide particles. J. Mater Sci. 27 719-728 Kandori, K. Yasukawa, A. Ishikawa,T. (1996) Influence of amines on formation and texture of uniform hematite particles. J. Colloid Interface Sci. 180 446-452 Kaneko, K. Inouye, K. (1974) Electrical properties of ferric oxyhydroxides. Bull. Chem. 

Naono, H. Nakai, K. Sueyoshi,T. Yagi, H. (1987) Porous texture in hematite derived from goethite mechanism of thermal decomposition of goethite. J. Colloid Interface Sd. 120 439-450... 

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