Detecting Gold Nanoparticles through Polarized Light: An Experiment Explanation

AI Thread Summary
The discussion centers on an experiment involving the creation of gold nanoparticles through colloidal gold. The key point is the use of polarized light to detect the presence of these nanoparticles. When light was shone at a 90-degree angle, it did not pass through the colloid, indicating that the nanoparticles were present and interacting with the light. This phenomenon is linked to the Tyndall effect, which explains how light scattering occurs with particles of a certain size, confirming the presence of nanoparticles in the solution. The conversation also seeks clarification on the specific setup and angles used during the experiment to better understand the observations made.
lo2
We a did an experiment with Colloidal gold, in which we created gold Nano particles. Our teacher told us that we could detect that we had created nanoparticles by shining polarized light on it. We shined light on it from a 90 degrees angle and then we could not see the light on the other side of the glas as if something inside had stopped the light. Could you please exlpain to me why that proves we have created nanoparticles?
 
Chemistry news on Phys.org
lo2 said:
We a did an experiment with Colloidal gold, in which we created gold Nano particles. Our teacher told us that we could detect that we had created nanoparticles by shining polarized light on it. We shined light on it from a 90 degrees angle
90 degrees to what? Please describe or draw the setup so it's clear what angles and direction we are talking about.

... and then we could not see the light on the other side of the glas as if something inside had stopped the light. Could you please exlpain to me why that proves we have created nanoparticles?
It's hard to tell exactly what is being observed. If you're just looking for a beam of light inside the colloid (the direction of the beam perpendicular to your line of sight) and don't see it because the colloidal particles are nanosized, then you want to look up the Tyndall effect.
 
I want to test a humidity sensor with one or more saturated salt solutions. The table salt that I have on hand contains one of two anticaking agents, calcium silicate or sodium aluminosilicate. Will the presence of either of these additives (or iodine for that matter) significantly affect the equilibrium humidity? I searched and all the how-to-do-it guides did not address this question. One research paper I found reported that at 1.5% w/w calcium silicate increased the deliquescent point by...
Back
Top