OMG POP ROCKS

Julie made a post on her blog Julie’s Chemistry Connections about Pop Rocks last Wednesday!

I LOVE POP ROCKS.

According to her blog, carbon dioxide is trapped in the candy, which is what makes pop rocks do tht awesome popping in your mouth. Mmmm~ So cool! I love the sound pop rocks makes. Pop rocks apparently has less CO2 than soda. I don’t even like the carbonation in soda that much at all, but I sure do love pop rocks! In fact, the carbonation is about 1/10th as much as you would get in a mouthful of cola!

Here’s more information I learned about pop rocks, candy which ahs been gasified with CO2 using a patented process.

Pop Rocks are made by heating a solution sugar, lactose, corn syrup, water, and artificial colors/flavors until the water boils off and combining it with carbon dioxide gas at about 600 pounds per square inch (psi). When the pressure is released, the candy shatters into small pieces, each containing bubbles of pressurized gas which can be seen if you examine the candy with a magnifying glass.

While Pop Rocks are totally safe, artificial colors, flavors, sugar, and corn syrup aren’t too safe to have large amounts of. Brush your teeth and eat healthy, kids!

21st Century Alchemist’s Gold

Remember how we learned that alchemists tried to turn other elements into gold? That wasn’t too plausible back then; they needed a greater knowledge of science to realize that it was nearly impossible to alter the number of protons in an atom to make it gold.

These days, a more coveted transformation would be to turn carbon dioxide, which the earth has a bit too much of, into fuel or useful industrial chemicals. Researches from Brown have shown that by maximizing the long edges of gold nanoparticles, they may make better catalysts for CO2 recycling.
Click here for the article on phys.org.

“Our study shows potential of carefully designed gold nanoparticles to recycle CO2 into useful forms of carbon,” said Shouheng Sun, professor of chemistry.

 

CO2 is a very stable molecule, however, and much be reduced to an active form like CO to be useful. CO is used to make synthetic natural gas, methanol, and other alternative fuels, but converting CO2 to CO is not easy. Gold foil has been used for this conversion, but rather inefficiently, as gold tends to react with both CO2 and the water it is dissolved in, creating a hydrogen byproduct rather than CO.

The Brown experimental group shrank the gold down to nanoparticles to make it more selective for CO2.

The size of these gold nanoparticles is crucial, because edges produce more desired results than corners.

That’s very interesting to me! Since nanoparticles are so… well, nano, I imagine them to be so small that I’ve never really thought about how some might have relatively longer “edges” to them than others. According to the article, Nanoparticles of 8 nm appear to have a better edge-to-corner ratio than 4 nm, 6 nm, or 10 nm nanoparticles. Eight nanometer particles achieved a 90% rate of conversion from CO2 to CO. How cool!

“What we were able to figure out is that the most active sites for converting CO2to CO are the edge sites, while the corner sites predominantly give the by-product, which is hydrogen. As you shrink these particles down, you’ll hit a point where you start to optimize the activity because you have a high number of these edge sites but still a low number of these corner sites. But if you go too small, the edges start to shrink and you’re left with just corners.” said Andrew Peterson, professor of engineering.

The researchers believe these findings could be an important new avenue for recycling CO2 on a commercial scale. They are now working on new particles to maximize the active sites on these nanoparticles.