Dejan Vinković

A new crystal in our collection: beautiful Calcium Copper Acetate CaCu(CH₃COO)₄·6H₂O It took some time for these crystals to appear because the solution had too much copper in the beginning and black Copper Acetate crystals formed first.
🧪🥽 #EduSky

Hidden worlds in a speck of light A simple home-made gadget can open a window into the language of atoms and molecules.

Matter is made up of atoms and molecules, and they are very picky about the colors they emit.
Find out how to build your own gadget at home for observing the language of atoms and molecules.
Ideal for kids!
🧪🍎🥽#EduSky 🔭

Crystals of urea. When the crystal needles reached the jar wall, they bent but kept growing.
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The Winder - a new super hero! He can wind a coil super quickly!!!
(my kid's idea of fun with LEGOs).

We don't have a macro lens to capture nice photos of beetles. So, we improvised and experimented with various manual parameters on the camera. The learning curve is now quite steep!
Note: please, don't mind the needle position! We didn't know initially the rules of pinning.
#entomology #EduSky

What a nice day - beetle identification fever! Plenty of species recognized.

Unexpected beauty: we are trying to grow copper-calcium-acetate crystal at home, but we put too much calcium acetate into the solution. This is why it crystalized first, but this is such a strange crystal formation! Tiny fragile needles forming a mass that feels like velvet on touch!
🧪🍎 ChemSky

My kid and I managed to grow "snowflake" crystals again. This time we were a more analytic and prepared several solutions of different ratios between blue vitriol and monopotassium phosphate.
Next challenge - how to make them bigger and more regular.
🧪 🍎 ChemSky

Snowflake crystals are back! My kid and I managed to grow them again! We mixed 12g of blue vitriol and 22g of monopotassium phosphate, filtered the sludge, and then waited for 10 days. They first appear on the surface and then sink to the bottom where they keep growing.
🍎🧪#ChemSky

Cosmic rays in DIY cloud chamber:
straight track: fast muon or electron
curved track: slow electron (produced probably by muon transformation)
Work in progress...

My kid and I trying to repeat the crystallization procedure where we got snowflake crystals from a mixture of monopotassium phosphate and copper sulfate.
This time a partial success: blue crystals appeared at first, but then snowflakes crystalized.
The recipe needs refinement.
🧪🍎 ChemSky

Red printer ink mixed with potassium alum solution gets integrated into the growing crystals in this strange way.
It deforms the crystal and creates a yellow cross.
We are trying to grow bigger crystals, but it seems that the ink prevents growth of perfectly smooth surfaces.
🧪🍎#ChemSky

Potassium alum crystal mixed with ink from yellow fluorescent marker and contaminated with something...
My kid was preparing this for fun, but he didn't clean the container before pouring in this solution. The contaminant pushed the crystal into an almost perfect cube.
🧪🍎 #chemsky

I first soaked beans in water full of carbon quantum dots (CQT) and then planted them and watered with more CQTs. Some other grains are sitting on a cotton soaked with CQTs.
Now I hope plants will grow and glow under UV! 😀
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A table of 6 photos of test tubes.

A fun part of simple homemade carbon quantum dots is the desire to experiment with various compounds because it is a simple procedure.
Mix 0.1g of each material, three drops of water, and heat it in a microwave oven.
Here are our three mixtures that produced bright luminescence.
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Alum crystal grown in a solution colored with yellow marker ink glows bright green under UV (black) light.
We managed to grow a big crystal, which gives this impressive glow! This is a real crystal! Like a light bulb in your hand! If you are a STEM enthusiast, you should try it!
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Glowing blue droplets falling through water in a glass container.

Glowing blue droplets falling through water in a glass container.

Glowing blue droplets falling through water in a glass container.

Glowing blue droplets falling through water in a glass container.

Playing with drops of homemade concentrated carbon quantum dots under UV light.
It is amazing that such tiny 3nm particles can be easily made in a kitchen microwave oven.
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4 test tubes: normal light, under UV, blue & green laser.

Carbon quantum dots (CQT), synthesized from urea and citric acid in my kitchen microwave oven, showing fluorescence in different colors when excited by UV light (365nm), blue laser (405nm), and green laser (532nm). The first photo is under normal lightning.
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Fluorescence of carbon quantum dots, synthesized from urea and citric acid, shows the optics of test tube. The UV light enters from below and the tube bottom behaves like a lens.
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Light blue fluorescent liquid in a test tube, with UV light source in the background.

Yellow and light blue fluorescent liquids in test tubes, with UV light source in the background.

Yellow and light blue fluorescent liquids in test tubes, with UV light source in the background.

My first carbon quantum dots - tiny (2-3nm) carbon particles that fluoresce under UV light!! This will be now a playground for my kid and me for a while. Instruction on how to synthesize this at home are very simple:
www.youtube.com/watch?v=Ipfb...
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Totally cool fractal shapes formed by electrolysis. Copper electrodes for a copper fractal in copper(II) sulfate solution (blue); iron electrodes for an iron fractal in iron(II) sulfate solution (yellow).
Perfect for physics-chemistry-mathematics mix of education topics and easy to setup.
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Fortunately not - this is a cropped image of a bigger photo from a bit further away.

Nope, they appeared by ordinary evaporation. That's why we want to explore it further for fun.
bsky.app/profile/deja...

Aargh! We're trying to repeat the crystallization procedure where we got snowflake crystals from a mixture of monopotassium phosphate and copper sulfate. But this time we got this pretty crystal, similar to copper sulfate crystals. I'm afraid that we're missing some important detail in our notes!🧪🍎🥽

It took me some time to realize why the flame on my kitchen stove suddenly turned orange. It was not b/c of incomplete combustion. My kid was using a compressor nebulizer to treat his stuffy nose. This created a mist of saline solution, which contains sodium that emits orange light when excited.
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Sometimes simple toys can be quite educational.
I bought lots of magnetic blocks and then my kid and I looked at various ways how to build fullerenes and nanotubes.
#EduSky #ChemSky 🧪 🥽

I can comment only on the fruit pigment color - it is indeed red and this is something that everybody notice, but then we do not ask ourselves what makes berries appear blue.
This is why I always emphasize in STEM courses to kids that they should never underestimate the power of simple questions!

Study: Tiny Structures in Wax Coating of Blue-Pigmented Fruits Give Them Their Blue Color | Sci.News Scientists have investigated dark pigmented fruits with wax blooms, like blueberries, plums, and juniper cones, and found that a structural color mechanism is responsible for their appearance.

I love this kid of research that reveals something new in mundane items!
The blue color of blueberries, plums, or juniper cones is not due to a blue pigment! It comes from tiny randomly arranged wax crystals boosting UV and blue light by interference of scattered light waves.
#EduSky #ChemSky 🧪

Have you noticed that sometimes specks floating on water attract or repel one another? This is called the Cheerios effect and it is an fun example of surface tension force in action.
en.wikipedia.org/wiki/Cheerio...
#EduSky 🧪

With crystals you have to be patient and they will return with beauty of colors and shapes.
Our home made crystals are growing and some are ready to be stored in our collection.
Most importantly, we got ideas for new mixtures of salts where we can expect new surprises!
#EduSky #ChemSky 🧪