Quantum Dots From Sugars With Acids and Bases.
by SHOE0007 in Workshop > Science
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Quantum Dots From Sugars With Acids and Bases.
A quick Intro what are Quantum dots?
They are Nanoparticle or Nanosemiconductor molecules in this case acidified carbon from sugar that has been treated with either Potassium carbonate or Sodium carbonate to glow under UV. A 405 nm laser produces lattices in the sugar that when excited jump from one orbital level to another releasing Photons or light. It also dependant on the size of the dot too.
There are organic dots made of sugar or toxic dots made of CdS.
This is an example of CdS type of Quantum dots.
Mine are sugars so they are less toxic and more useful since some types can be used with folic acid to detect cancer and diseases.
But I assume also that Quantum dots with lasers 405 nm could be used for other stuff like holograms and illusions to the bright light they emit when exposed to the laser beam.
Supplies
Hotplate and magnetic stirrer.
Beakers
Stir rod
Digital IR thermometer.
Jewelry Scale
100 mw 405 nm Laser.
Chemicals:
Sucrose.
Lactose.
Agave,
Stevia.
Acetic acid 5 percent.
Hydrochloric acid 31.45 percent.
Sodium carbonate
Potassium carbonate.
ph paper (Important).
Sugar Dots With Sucrose, Agave, Lactose and Stevia. Acetic Acid Method.
We weigh out 50 g of Sucrose sugar with 200 ml of tap water and add 50 ml of 5 percent Acetic acid we then stir and heat the solution for a few hours and use a digital IR thermometer to measure the temp. When it reaches 60 deg C for a few hours allow it to cool to room temp and pour into a 1 L to 2 L beaker and with PPE slowly add sodium carbonate until the Ph is 8.
Fire the laser and repeat the stuff for Agave, Lactose, and Stevia. Weighing out 50 g of sugar to 200 ml water plus 50 ml of acetic acid.
Then add the sodium carbonate to the mix allowing the beaker to fizz and slowly release CO2 as the solution becomes Basic. Sodium carbonate is a strong base always wear gloves and eye protection when working with it.
Voila, you can make Acetic based Quantum dots this way.
This info above is where I started experimenting with Quantum dots, to begin with. Cool video (Referenced.)
Sugar Quantum Dots With Hydrochloric Acid and Potassium Carbonate.
This time we are heating 50 grams of sugars (Sucrose, Agave (Mainly fructan sugars), Lactose, and Stevia in 200 ml water with 20 ml of concentrated Hydrochloric acid.
Warning: Hydrochloric acid and Potassium carbonate are very destructive to skin and eyes always wear gloves and eye protection when working with these chemicals.
Heat them on a hot plate and stir rod for 1-2 hours with heating 50-60 degrees C allow them to cool to 40 degrees C or so and put in a clean 1-2 L beaker and add 20 g of Potassium carbonate until the pH is around 8 to 9.
Shine the laser onto the fresh Quantum dots that you just have made.
I shined them vertically and horizontally to see the beam. You can see the beam clearly in the lactose and other quantum dots too.
I find the Hydrochloric acid method the best with K2CO3 (Potassium carbonate) one of the best methods. Altho you can add 50 ml 98 percent sulfuric acid to 50 g sugars I tried it I did not get good results the carbon dyed the solution however I will show a video on how to do this as well.
Comparing Acetic Acid and Hydrochloric Acid Quantum Dots.
Compared to water no fluorescence occurred but when sugars were heated to 60 degrees or higher with Acetic acid with Sodium carbonate some weak quantum dots were made. If you follow a 1:1 ratio of Sugars to sulfuric acid you can make really good quantum dots however that a lot more expensive 60 dollars for 500 ml of Sulfuric acid from Prolab Scientific so not a lot of people can afford it.
I recommend using Sugar quantum dots with Hydrochloric acid 31.45 percent since the acid is a lot stronger than acetic acid at a ph of 3 compared to ph 1. You can make very good Quantum dots from sugars and acids and the sugar plus Hydrochloric acid and Potassium carbonate (stronger base) works a lot better.
Thank you for reading this Instructable.
SHOE0007.