Dynamic viscosity technological applications

The physical and mechanical properties of materials are the primary concern for their use in applications. However, these properties reflect the motion of the constituent molecules, which makes study of the latter essential to the fundamental understanding necessary for developing new technologies. The structural dynamics is quantified by a time constant, t, which is a measure of the time scale for reorientation of a small molecule or the correlated conformational transitions of a few backbone bonds in a polymer. For both liquids and polymer melts the structural relaxation time (and viscosity, /, which is roughly proportional to t) varies with temperature, with Arrhenius behavior... 

Thermophysical properties are defined, in Chapter 9 by Cagran and Pottlacher, as a selection of mechanical, electrical, optical, and thermal material properties of metals and alloys (and their temperature dependencies) that are relevant to industrial, scientific, and metallurgical applications, and this covers a wide range of different material properties obtained by numerous different measurement techniques. The focus in Chapter 9 is, however, on thermophysical properties that are accessible through dynamic pulse calorimetry Other non-calorimetric techniques have been developed but, with the exception of levitation (needed to measure technologically important properties like viscosity and surface tension) have been excluded from consideration. 

In this chapter the surface chemistry of selected nonsulflde flotation systems, including soluble alkali halide salts, phyllosilicates, quartz, and some naturally hydrophobic minerals, were studied using MD simulation. Issues such as water structure and dynamics, solution chemistry, interfacial water structure, and adsorption states for surfactants and macromolecules were examined. It is clear that MD simulation has been validated as a very useful tool to study the surface chemistry of certain flotation systems. As a complement to experimental studies, MD simulation analysis provides further information and understanding at the atomic level to issues such as water structure, particle dynamics, solution viscosities, mineral surface wetting characteristics, surface charge, and adsorption states. A wide application of MD simulation in the study of mineral surface chemistry is expected to have a significant impact on further advances in flotation technology. 

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