Light scattering studies QELS

Dynamic surface tension has also been measured by quasielastic light scattering (QELS) from interfacial capillary waves [30]. It was shown that QELS gives the same result for the surface tension as the traditional Wilhelmy plate method down to the molecular area of 70 A. QELS has recently utilized in the study of adsorption dynamics of phospholipids on water-1,2-DCE, water-nitrobenzene and water-tetrachloromethane interfaces [31]. This technique is still in its infancy in liquid-liquid systems and its true power is to be shown in the near future. 

The problem of particle nucleation was first addressed in the 1980s by Candau and coworkers [14,104] for the case of water-in-oil microemulsions. Their studies concerned the polymerization of acrylamide inside water-swollen micelles stabilized by AOT and dispersed in toluene. A thorough investigation of the structures prior to and after polymerization by elastic and quasi-elastic light scattering (QELS), viscomelry, and ultracentrifugation experiments yielded two key experimental results ... 

In recent years, the quasi-elastic light scattering (QELS) method has become increasingly routine in experimental studies of polymer dynamics in both dilute and concentrated solutions. It allows us to obtain information about the possible modes of Brownian motion of a polymer molecule either isolated or entangled with others. Leaving its technical details and various practical applications to reference books [38], we here give a brief account of its important aspects which are closely related to the current theory of dilute polymer solutions. 

Measurement System Motions of polymer molecules in solution can be conveniently studied by using dynamic light scattering (DLS). It is also called quasi-elastic light scattering (QELS) and photon correlation spectroscopy... 

Structural properties can be investigated by small-angle neutron scattering (SANS) [3-5] or by quasi-elastic light scattering (QELS) [6-8]. Interphasal properties can be studied by dielectric spectroscopy and electrical conductivity mea-... 

Dynamic light scattering involves the study of time-dependent fiuctuations in the intensity of scattered light which are the result of the Brownian motion of the particles. The random movement of the particles causes the distances between the particles to fiuctuate, causing constantly varying constructive and destructive interference patterns. This time-dependent fiuctuation in the intensity can be correlated with itself to obtain the diffusion coefficient of the particles. This method is also called photon correlation spectroscopy (PCS) and quasi-elastic light scattering (QELS) [21, 22]. 

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