Microstructure formation

Another more abrupt transition in this order parameter occurs at a = 0.7 under the arrow labeled b. This transition is assigned to the onset of irregular bicontinuous microstructure formation, and is indicated qualitatively by the marker illustrated in Fig. 3, where the onset in AOT self-diffusion increase occurs. 

Schmidt, M. A. 1998. Wafer-to-wafer bonding for microstructure formation. Proc. IEEE 86 1575-1585. 

These coarse-grained MD calculations helped consolidate the main features of microstructure formation in CLs of PEFCs. They showed that the final microstructure depends on carbon particle choices and ionomer-carbon... 

In this chapter we have outlined how the use of a universal thermodynamic approach can provide valuable insight into the consequences of specific kinds of biopolymer-biopolymer interactions. The advantage of the approach is that it leads to clear quantitative analysis and predictions. It allows connections to be made between the molecular scale and the macroscopic scale, explaining the contributions of the biopolymer interactions to the mechanisms of microstructure formation, as well as to the appearance of novel functionality arising from the manipulation of food colloid formulations. Of course, we must remind ourselves that, taken by itself, the thermodynamic approach cannot specify the molecular or colloidal structures in any detail, nor can it give us information about the rates of the underlying kinetic processes. 

Although equation 33 gives a physical description of the mechanism of the instability that leads to microstructure formation during solidification, it is not rigorous because it does not consider the effects of the rates of heat and species transport on the evolution of the disturbance. Because of this deficiency, equation 33 cannot be used as a basis for further analysis of microstructure formation. This deficiency is shown clearly by the inability of equation 33 to predict the spatial wavelength of the microstructure formed along the interface. 

Kondo, N., Suzuki, Y., and Ohji, T., Superplastic sinter-forging of silicon nitride with anisotropic microstructure formation , J. Am. Ceram. Soc., 1999, 82, 1067-9. 

Microstructure Formation in Mesophase Carbon Fibers and Other Graphitic Materials... 

We hope to have demonstrated that computer simulation of transport and transformation processes on digitally reconstructed multi-phase media can be beneficial to practical chemical engineering applications. We believe that as chemical engineering becomes more product-oriented, the need to model phenomena that control material microstructure formation will gain in importance. We hope that this chapter will provide a useful starting point for those who wish to familiarize themselves with the relevant computational techniques. 

The forces leading to microstructure formation in complex fluids are relatively few Excluded-volume, van der Waals, and electrostatic forces are the main ones. In some fluids, hydrogen bonding, hydrophobic, or various solvation forces are also important. Simplified theories can account for the effects of these forces on fluid structure and, to some extent, on relaxation rates. 

Ceramics obtained from polymeric precursors are usually amorphous. Since substantial thermal activation is required for nucleation and crystallization, precursor-derived ceramics (PDCs) frequently remain amorphous or nanocrystalUne up to rather high temperatures. For example, crystallization of a number of quaternary Si-B-C-N ceramics is retarded even up to 1800°C, resulting in excellent thermomechanical properties. Nevertheless, crystalline materials are of great interest because their microstructure formation can be controlled during devitrification, providing a means for stabilizing nanosized morphologies. 

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