Elastic light-scattering detection

In the particular case of a bimodal particle size distribution where the second size is very small, detection can be difficult This is illustrated by the data in Table 12.13, which shows that the bimodal characteristic was measured by transmission electron microscopy (TEM), capillary hydrodynamic fractionation (FlowSizer), and by SFFF, but not by quasi-elastic light scattering (NICOMP 270 or Brookhaven B 1-90). While QELS (or PCS) instruments are capable of... 

The dynamics of the collective excitations can be determined conveniently by photon autocorrelation spectroscopy, which is also called self-beating, time-resolved Rayleigh or quasi-elastic light scattering spectroscopy [29]. Here the time autocorrelation function of the scattered light intensity G (t) is measured, which, in the heterodyne detection regime, is given by ... 

In order to image the distribution of the solvent, the solution and CO2 and the location of detectable particle formation simultaneously, the setup from the experiments before has to be adapted to other requirements. For this scope, a three-camera system has to be applied as shown in Fig. 24.8. Two cameras are required to detect the inelastic Raman signals, which are scattered from the organic solvents and the CO2 molecules, and therefore indicate the distribution of the solvent and the antisolvent. The third camera is taken to detect the elastic light scattering, which comes from phase boundaries, and therefore indicates the presence of a multiphase flow. The light scattering processes are excited with a pulsed frequency-doubled... 

In addition to acoustical methods, which take advantage of the fact that gas nuclei (i.e., stable microbubbles) are elastic bodies and thus absorb sound energy (ref. 4,5,9,25,26,31,32,50), another class of methods for detecting these gas microbubbles that has been employed repeatedly is based on their optical behavior. Specifically, most of these optical methods involve detection of these long-lived microbubbles in water from the light scattered by them (ref. 5,26,59,60,127). 

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