Scattering Tyndall

Tyndalization Tyndall scattering Type 4340 alloy steel n-Type dopants p-Type doping... 

Tyndall scattering also causes the blinding effect of shining a car headlight directly into a thick bank of fog or mist it also yields the beautiful iridescent colours on the wing of a butterfly or peacock tail, and an opal and mother of pearl. A good potter can reproduce some of these optical effects with so-called iridescent glazes, which comprise colloidal materials. 

Figure 5. Difference in ultraviolet spectra of a standard avidin solution and a solution of avidin in which an aliquot of a DMPE-B-C12E8 solution (10"3 M C12E8,1.25 x 10 M DMPE-B) has been added. Initially, a difference spectrum similar to that observed solely for the hyperchroic shift (Figure 3) is obtained. As time proceeds, the absorbance far exceeds that attributable to the hyperchroic shift, and the spectrum is typical of absorbance due to Tyndall scattering in which the magnitude of the absorbance decreases with the fourth power of the wavelength.

As soon as a detectable drop in the meniscus was observed, the entire contents of the flask were immediately dumped into a rapidly stirred short-stop solution of nitrite in sulfuric acid. Careful Tyndall scattering observations confirmed that no polymer particles had formed. The entire reaction mixture was then exhaustively extracted with benzene. Combined benzene extracts were rotary-evaporated, and the residual product was analyzed by IR spectroscopy, vapor pressure osmometry and gel permeation chromatography. 

Ideally, the absorbance that occurs during UVW IS measurements should be due only to the target analyte. However, in the UVA IS part of the spectrum both Rayleigh and Tyndall scattering may interfere. With significant scattering quantitative analysis is seriously impaired. The usefulness of UV analysis for qualitative and quantitative characterisation is also restricted by the poor selectivity of the... 

These bands are due to the fact that the incident light on the sample being examined is not just absorbed or transmitted but is also diffused in all directions (thus even arriving at the emission monochromator) by the molecules themselves (solvent and solute), by the air-wall and wall-solution interfaces of the cell (Rayleigh scattering) or by the presence of small suspended particles (such as dust, Tyndall scattering). This type of diffused light is always observed when you are... 

The basis for these optical methods is found in Rayleigh s law (c/. chapter III) w hich states that the Tyndall scattering is proportional to the square of the volume of the particles. Therefore, although the number of particles decreases during flocculation,... 

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