Undergrad Colloid complex refractive index from UV-vis spec

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The discussion revolves around using the damped wave approximation and Beer's law to determine the complex refractive index of colloids through UV-vis spectroscopy. It suggests that absorbance can be expressed mathematically, allowing for the extraction of the extinction coefficient (k) as a function of wavelength. Fitting a series of Lorentz oscillators to this data could yield the refractive index (n). However, caution is advised regarding the understanding of the material's physics, as misinterpretation could lead to inaccurate results. Accurate knowledge of the material is crucial for reliable outcomes in this analysis.
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Can I determine the complex refractive index (n + ik) of a colloid via UV-vis spectroscopy?
Hi everyone,

I am wondering, can I use the damped wave approximation for light travelling through a medium along with Beers law to spectroscopically determine a colloid complex refractive index.
Thanks!

Absorbance = exp (- 2πkx/λ) = ecl
 
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I think it's possible. You could extract k as a function of wavelength, and then fit a series of Lorentz oscillators to it. This would then give you n. Beware though, if you don't understand the physics of your material, then I'd say that you could end up with numbers that aren't a good match to reality.
 
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