Dynamic phase segregation

In this section, we describe the role of fhe specific membrane environment on proton transport. As we have already seen in previous sections, it is insufficient to consider the membrane as an inert container for water pathways. The membrane conductivity depends on the distribution of water and the coupled dynamics of wafer molecules and protons af multiple scales. In order to rationalize structural effects on proton conductivity, one needs to take into account explicit polymer-water interactions at molecular scale and phenomena at polymer-water interfaces and in wafer-filled pores at mesoscopic scale, as well as the statistical geometry and percolation effects of the phase-segregated random domains of polymer and wafer at the macroscopic scale. 

A Dynamic Mechanical Study of Phase Segregation in Toluene Diisocyanate, Block Polyurethanes... 

Several groups, including ours, followed the latter path, studying the structural and dynamical properties of water/Nafion mixtures with atomistic simulations. Let us first briefly consider the key chemical features of the ionomer and the nature of the phase segregation. The chemical composition of Nafion is given by ... 

Gas-liquid phase segregation is typically required following some other separation process, such as distillation, absorption, evaporation, gas-liquid reactions, and condensation. Before separation techniques or equipment can be selected, the parameters of the separation must be defined. Information on volume of gas or liquid, volume ratio of the phases, and disper -phase particle size—that is, drop or bubble size-should be known or estimated. For existing operations, measurements are a possibility, while for new facilities analogies from data on other processes could be used. Laboratory or pilot riant tests may be considered, but it is difficult to maintain all fluid dynamic properties constant while chaining scale and wall effects may be significant on the small scale. 

Solvent Effects The essence of choosing different solvent types, mixed solvents, and solvent additives is to better control the time and degree of phase segregation of the blending film. The spin casting is a short and dynamic process that, in most... 

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