Directional interface morphology

Alternatively, delamlnatlon may not be related directly to permeation, but may be due Instead to thermal and/or UV effects that are followed by the corrosive failure. Some studies and models Indicate that the polymer/metal Interface morphology, and the changes In the morphology with exposure to the environment, play a key role In corrosion rates. These characteristics may be even more Important In corrosion control than either the diffusion of vapors through the pol5mier or the Inherent corrosion resistance of the metal. 

Kornyshev, A. A. and M. Urbakh, Direct energy transfer at electrified liquid-tiquid interfaces a way to study interface morphology on mesoscopic scales, Electrochem Commun, Vol. 6, (2004) p. 703. 

The system Ni-Al203 was chosen for study primarily because it is of interest as a practical composite system ( ), but also because single-crystal aluminum oxide, sapphire, is transparent in the visible region. The latter feature allows direct observation of internal interface morphologies without any disturbance to the system. 

Anionic diffusion in the oxidation of a convex surface creates a situation which is the reverse of that just described. The oxide is in tension along planes parallel to the surface and fracture may be expected to occur readily in perpendicular directions and starting from the gas/metal interface. Although very thin films may have resistance to fracture, thick films frequently acquire the morphology shown in Fig. 1.83. 

Fabrication processing of these materials is highly complex, particularly for materials created to have interfaces in morphology or a microstructure [4—5], for example in co-fired multi-layer ceramics. In addition, there is both a scientific and a practical interest in studying the influence of a particular pore microstructure on the motional behavior of fluids imbibed into these materials [6-9]. This is due to the fact that the actual use of functionalized ceramics in industrial and biomedical applications often involves the movement of one or more fluids through the material. Research in this area is therefore bi-directional one must characterize both how the spatial microstructure (e.g., pore size, surface chemistry, surface area, connectivity) of the material evolves during processing, and how this microstructure affects the motional properties (e.g., molecular diffusion, adsorption coefficients, thermodynamic constants) of fluids contained within it. 

Fig.20 Top row single unit-cell models of core-shell double gyroid (Q230), orthorhombic (O70), and alternating gyroid (Q214) cross-sectioned to reveal interfacial configuration. Bottom row. direct projections of cross-sectioned interfaces. Sketches of PI-fi-PS-fi-PEO chains show how each morphology is assembled. Projections appear to scale that is, the core-shell double gyroid unit cell is roughly twice the thickness of the other two. From [75], Copyright 2004 American Chemical Society...

Example 1. Under the phase separation process, the time dependence of the interface area or the maximum wavevector does not exhibit any specific behavior that could be directly related to the morphological transformations that... 

Nowadays attention is turned also to the supermolecular level, that is, to the morphologic aspects, to the nature of interfaces, to the formation of new phases, or of particular aggregates (liquid crystals, gels, etc.). Interest has also been directed to the study of chain mobility for its influence on frictional properties of polymers. In recent years there have been many successful approaches to a microscopic theory (in contrast to a phenomenological approach) of the physi-comechanical behavior of macromolecular materials. 

---