Intensity of scattered light

It is well known that the intensity of scattered light varies as the fourth power of the frequency, and based on this alone one would predict the Stokes lines to be less intense than the anti-Stokes by a factor of... 

Zimmt has reported the intensity of scattered light at various angles of observation for polystyrene in toluene at a concentration of 2 X 10" ... 

The last factor is equal to 1+cos 0. The combined intensity of scattered light at a distance r and in a direction specified by 6 (Fig. 43) due to all particles in unit volume (N/V) of the very dilute solution becomes... 

Ts = intensity of scattered light transmitted by the sample Tj = intensity of incident light... 

For a vibration having a frequency v, the Stokes and anti-Stokes spectra correspond to bands at v0 — v and v0 + v. The spectra are usually presented as the intensity of scattered light vs. the shift, v0 — v, in cm 1. 

When the electric field strength of the incident light is ED, the induced dipole will be m, = aE0 where a is the optical polarisability. The electric field strength of radiation scattered by the induced dipole Es, depends on second derivative of m1 with respect to time. The useful experimental quantities are intensities of scattered light (Is) and incident important light (is). These are respectively proportional to Es2 and E02, averaged over a vibrational period, i.e., from time t = 0 to 10/C, where 1 is wavelength of... 

Photon correlation spectroscopy (PCS) has been used extensively for the sizing of submicrometer particles and is now the accepted technique in most sizing determinations. PCS is based on the Brownian motion that colloidal particles undergo, where they are in constant, random motion due to the bombardment of solvent (or gas) molecules surrounding them. The time dependence of the fluctuations in intensity of scattered light from particles undergoing Brownian motion is a function of the size of the particles. Smaller particles move more rapidly than larger ones and the amount of movement is defined by the diffusion coefficient or translational diffusion coefficient, which can be related to size by the Stokes-Einstein equation, as described by... 

The intensity of scattered light or turbidity (t) is proportional to the square of the difference between the index of refraction (n) of the polymer solution and of the solvent ( o), to the molecular weight of the polymer (M ), and to the inverse fourth power of the wavelength of light used (A). Thus ... 

In the determination of M , the intensity of scattered light is measured at different concentrations and at different angles 6). The incident light sends out a scattering envelope that has four equal quadrants (Figure 3.11a) for small particles. The ratio of scattering at 45° compared with that at 135° is called the dissymmetry factor or dissymmetry ratio Z. The reduced dissymmetry factor Z is the intercept of the plot of Z as a function of concentration extrapolated to zero concentration. 

The intensity of scattered light depends on a number of parameters including the size, shape, and concentration of the suspended particles,... 

If the CONTIN algorithm was running in equal spacing on the logarithmic scale and the linewidth distribution was normalized by the area, then the intensity of scattered light for each fraction P can be expressed as G(lnP ) which is related to G(Pj ) by the relation... 

Ringsdorf, Sackmann, and coworkers characterized the behavior of mixtures of the polymerizable bis-dienoylammonium lipid 14 and DMPC [42]. Evidence for phase separation in these mixtures was obtained from electron microscopy and light scattering. Since the intensity of scattered light is dependent on the physical state of the membrane, plots of scattering intensity versus temperature exhibit inflections at phase transitions. This technique was used in conjunction... 

The equation in Step 6 in Table 5.1 shows that the intensity of scattered light depends on the square of polarizability. We conclude, therefore, that the way to adapt this equation to the scattering by solutions is to replace a2 in the above equation by (5a)2... 

Note that e here does not stand for permittivity.) Now let us examine the relationship between absorbance and the intensity of scattered light. In a light scattering experiment with nonabsorbing materials, the intensity of the transmitted light equals the initial intensity minus the intensity of the light scattered in all directions Is ... 

FIG. 5.6 Definition of an element of area required for the summation over all angles of the intensity of scattered light. 

The Rayleigh approximation shows that the intensity of scattered light depends on the wavelength of the light, the refractive index of the system (subject to the limitation already cited), the angle of observation, and the concentration of the solution (which is also restricted to dilute solutions). In the Rayleigh theory, the size and shape of the scatterers (M and B) enter the picture through thermodynamic rather than optical considerations. 

The actual intensity of scattered light measured at a point C, denoted by ic, equals the product is times P(6). Therefore the experimental Rayleigh ratio obeys Equation (27) modified as follows ... 

At what angle is the intensity of scattered light largest for large particles Why ... 

What is an autocorrelation function Sketch qualitatively the autocorrelation function of the intensity of scattered light from a dispersion for a number of angles. 

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