Admagistr
Hazard to Others
Posts: 350
Registered: 4-11-2021
Location: Central Europe
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Mood: The dreaming alchemist
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The formation of the firely opal.
I found this advice to create a firely opal, in a physics forum. Does anyone have practical experience with this? I got tetraethylorthosilicate
yesterday;-)
For the first solution Add 12-17 parts of tetraethyl orthosilicate (TEOS) to 100 parts of alcohol (ethanol) with stirring. For the second solution Add
30-50 parts of ammonium hydroxide to 250 parts of alcohol. Next: Add the TEOS/alcohol solution to the ammonia/alcohol solution slowly with stirring.
Continue stirring for about an hour to allow the reaction to come to completion. Depending on the exact concentrations of reagents you will generate a
milky suspension of 250-400 nanometer silica spheres. Pour the suspension into a tube and allow it to settle. A thin layer of opal color will form in
a few days and within 2-3 weeks all the suspension will have settled out and formed a brightly diffracting layer of "opal" usually a few millimeters
thick depending on how much solution and the size and shape of the container. You can continue to make new batches and add to the container to
increase the thickness of the growing opal layer.
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wg48temp9
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Registered: 30-12-2018
Location: not so United Kingdom
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If you have not already seen it, check out The Thought Emporium youtube video on making opal
https://www.youtube.com/watch?v=d7MvGFX_VKo
I am wg48 but not on my usual pc hence the temp handle.
Thank goodness for Fleming and the fungi.
Old codger' lives matters, wear a mask and help save them.
Be aware of demagoguery, keep your frontal lobes fully engaged.
I don't know who invented mRNA vaccines but they should get a fancy medal and I hope they made a shed load of money from it.
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Morgan
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Registered: 28-12-2010
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An interesting flashing effect using silica nano spheres is used by a clam.
The electric clam is at the 10:45 minute mark.
https://youtu.be/Qw68XQQu55s
https://youtu.be/GRzeNlqnRxU
More thoughts on the nano spheres reflection
https://youtu.be/OLyeqo1qRVg
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Morgan
International Hazard
Posts: 1673
Registered: 28-12-2010
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Mood: No Mood
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A few tidbits perhaps of interest
How the Disco Clam Uses Light to Fight Super-Strong Predators | WIRED
https://youtu.be/3GLZAIaXudk
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