Housane
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Easy Colourful Quantum Dots
Today I managed to make green carbon quantum dots by dissolving 3g of sucrose in 10ml of water and 1ml of 30% HCl was added to make it acidic. It was
then heated at 80-90C for 10 minutes and the water was allowed to evaporate. After 5 mins the solution turned yellow and it got steadily darker. After
the 10 mins a distinctly sweet our could be smelt.
It was take off the heat and allowed to cool. The remaining black solution was dissolved in 150ml of water and then filtered, a dark filtrate was
collected. This was made neutral by addition of NaOH. These are quantum dots but to see them clearly i diluted them. In the pictures the range on the
lower level is 2 fully concentrated then 5 vials going from 25% to 5% in 5% increments. Feel free to ask any questions. The glow is poor as the light
is a cheap UV invisible ink pen, I will do better pictures on request.
Regards
Housane
  
[Edited on 18-6-2020 by Housane]
Green QD's so far
Feel free to correct grammar or incorect knknowledge. We are all learning.
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Housane
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More pictures
  
Green QD's so far
Feel free to correct grammar or incorect knknowledge. We are all learning.
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Ubya
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i have a request for you, could you check in a few months/a year if they still fluoresce the same?
i made some blue quantum dots via the hydrothermal method (pretty much the same thing you did but in a closed vessel and at 180°C instead of 90) a
year and a half ago, and now the solution fluoresces green and it is much much fainter, i suspect that with time the nano particles aggregate
somewhat, i would be interested to know how long it takes for yours
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feel free to correct my grammar, or any mistakes i make
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Housane
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Yeah sure,I will do an update in a year or so
Green QD's so far
Feel free to correct grammar or incorect knknowledge. We are all learning.
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draculic acid69
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This sounds a lot like making levulinic acid.
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mackolol
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And what's the chemistry behind it. What chemical is formed by heating sugar with HCl and then neutralising it?
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Housane
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The idea is you are breaking down the carbon and then slowly reforming it in such a way that lots of tiny particles are formed and this is what
changes the colour of the UV light. Thought emporium has a video about them. The acid slightly alters this. Others colours should be possible in Basic
solutions and the colour may change depending on what acid is used, more exeprimatation I need to do
Green QD's so far
Feel free to correct grammar or incorect knknowledge. We are all learning.
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Housane
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I think I have just made yellow quantum dots, I will post again when the solution is concentrated enough to get a good picture
Green QD's so far
Feel free to correct grammar or incorect knknowledge. We are all learning.
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wg48temp9
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While looking for a wiring diagram for my dishwasher, which I did not find, but I did find a paper describing how to make Doped/Co-Doped Carbon
Quantum Dots. I thought others may find it useful so I am posting it in this thread.
Attachment: carbon-05-00024-v2.pdf (5.1MB)
This file has been downloaded 336 times
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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Housane
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Registered: 3-9-2018
Location: Worcester, England
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Ubya, I have just checked them and both the green and the yellow glow exactly the same as before
Green QD's so far
Feel free to correct grammar or incorect knknowledge. We are all learning.
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