Mobility generalized

None of these terms appears to be completely satisfactory. The concept of "mobility in NMR spectroscopy is quite different from that in the field of separation science, where mobility generally requires a measurable degree of solubility and/or distillability in liquid or gaseous media, respectively. For example, polymethylene-like moieties, such as found in some coal components (0, are highly "mobile in NMR terms (1), without necessarily being extractable by solvents or distillable by nondestructive heating. 

Ionic mobilities generally have a temperature coefficient of around -i-2.5%/degree, but it is not exactly the same for all ions. Incidentally, water viscosity has a temperature coefficient of approximately -2.5%/degree. This sometimes leads to the erroneous conclusion that ionic mobility is, by definition, inversely proportional to liquid viscosity, which is an oversimplification, originating also from the following relationship ... 

Transport behavior Immobile Retained close to the source Low mobility Condense at mod. temp. mid-latitudes Mod. mobility Condense at low temp, (polar) Mobile General atmos. distribution... 

Typical data are shown in Fig. 4.18 for the electrophoretic mobility and surface charge density of Ti02 (mtile) as a function of pH in aqueous solutions of potassium nitrate (33). The -potential will show Ae same variation with pH since it is proportional to the mobility. For many oxides, -potential values determined from the mobility generally fall within the range of -HlOO to -100 mV. 

Electrical ionic mobility General ionic mobility bj ... 

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