Raleigh light scattering

The elastic constants of liquid crystalline polymers can be measured in terms of the Frederiks transitions under the presence of a magnetic or electric field. Raleigh light scattering is also a method for measuring the elastic constants. Those techniques successfully applied to small molecular mass liquid crystals may not be applicable to liquid crystalline polymers. This is why very few experimental data of elastic constants are available for liquid crystalline polymers. 

The Raleigh light scattering, another important approach to measure elastic constants and viscosities simultaneously, is applicable to liquid crystalline polymers as well. 

ELSD Evaporative light scattering detector Raleigh scattering of atomised eluent... 

The mechanism of light scattering is complex and is a result of a number of different mechanisms—Raleigh and Mie scattering, reflection and refraction [42]. The relative contribution of these processes is dependent upon the radius of the droplet compared to the wavelength of light of detector. 

Black polymers, such as polyacetylene, absorb all visible light, but opaque polymers scatter the incident light. As shown by Lord Raleigh, the turbidity r is related to the scattered light per unit volume, integrated over all angles. 

Raleigh horn. The collected scattered light is transmitted by an optical fiber to a photomultiplier. The photomultiplier current is amplified and recorded. 

Figure 15.5 Schematic of instrumental apparatus. The DT/MH-functionalized AgFON was surgically implanted into a rat with an optical window and integrated into a conventional laboratory Raman spectroscopy system. The Raman spectroscopy system consists of a Ti sapphire laser (Acx = 785 nm), band-pass filter, beam-steering optics, collection optics, and a long-pass filterto reject Raleigh scattered light. All of the optics fit on a 4 ft x 10 ft optical table.

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