Macroscopic correlation function spectroscopy

Fig. 25a, b. a. Collective diffusion coefficient D of a NIPA gel as determined by the kinetics of volume change, as a function of temperature. It diminishes at the critical point, b. collective diffusion coefficient as determined from the density fluctuations by use of photon correlation spectroscopy. The agreement between the results obtained from dynamics of microscopic fluctuations and from kinetics of macroscopic volume change is excellent considering the difficulty in the dynamic experiments... 

As polysaccharides tend to functionalize environmental phase space, for specification of polysaccharide dimensions, geometry and dynamics must be distinguished, although the transition is diffuse Whereas the dimensions of polysaccharide molecules in terms of sphere equivalent radii of mean excluded volume for macroscopic periods are up to maybe lOOnm only, dynamics of coherent supermolecular structures provide sphere equivalent radii that are more than one magnitude larger and enter the micrometer range. However, these structures are hidden if mass fractions are taken for illustration. Their identification typically needs sophisticated detection and specific scaling, for instance, photon correlation spectroscopy and representation of detected populations with respect to the square of coherent (occupied) volumes (Fig. 6C). 

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