Original air date:
10.24.07
Why Do Glowsticks Glow? Here's How To Make Your Own
This week, Chris Hardwick helps us make glowsticks—you know, those fluorescent things that you absolutely had to have with you at concerts when you were 13.
What makes a glowstick so pretty and glowy? When you snap the stick and shake it up, two liquids combine in what can be thought of as an industrial version of a firefly mating dance. It's called chemiluminescence, the production of light from chemistry.
So how do you make your own? First, we need some luminol—that’s the stuff they use on “CSI” to make bloodstains glow. Then we need 3 percent hydrogen peroxide and two big mixing bowls. We'll also need distilled water, sodium carbonate, and copper sulfate pentahydrate. The hydrogen peroxide you can get at a drugstore; the other stuff you can find on the Web.
OK, first step: Take half the water—one liter—and add to it the hydrogen peroxide. We're just diluting the peroxide, basically. Set this bowl aside for later.
Now, in the other bowl, dump the rest of the water and 4 grams of sodium carbonate, which helps all the other chemicals mix together better. It’s like the club soda in a mojito.
Add to the sodium carbonate mixture 0.4 grams of copper sulfate pentahydrate. It’s going to help light up the luminol, which is looking to steal electrons from metals—in this case, the copper in the copper sulfate (with blood, it's the iron in hemoglobin). Luminol can only dissolve in highly alkaline solutions—11.8 pH. Note to self: Don’t drink this. In fact, don’t even touch it.
And now we carefully add 0.2 grams of luminol to the sodium carbonate/copper solution. And here we are with a fully prepped solution, just waiting to glow.
Now let's return to the diluted hydrogen peroxide and add it to the luminol solution.
The hydrogen peroxide replaces two of luminol’s nitrogen atoms with oxygen, producing a bunch of electrons so excited that they kick out a blast of photons. That’s the glow in our glowstick!
So here we are, smug in the fact that we're not only surrounded by liters of eerie-looking glowing liquid—we even made it all ourselves!
Nerds rule.







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28 Comments

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10.24.07 11:22 AM PDT
Dr. Aunt Sally
We need to know WHY we should not touch this solution,
and what harms could result from it. SOMEONE will goof up,
we humans know. So MORE SAFETY, please! What to do with a spill, how to dispose of it, how long it glows, and what the radiation does......But it DID start to satisfy my curiosity about these things, which one sees lots of in tourist-laden border Mexican towns and where lots of uninformed people roam around blissfully waving these. THANKS!
10.24.07 2:03 PM PDT
Esther
I agree- this article left a lot of questions unanswered... how to dispose of this mixture. what happens if it gets on your skin, etc. shocking to be so cavelier about this.
10.24.07 5:34 PM PDT
Robert N. Nelson, Ph.D.
As a retired college chemistry professor who was also the department SAFETY OFFICER I was very frustrated that Mr. Hardwick was not wearing safety goggles as he mixed his chemicals. When I was teaching that was an offense which sent the student out of the lab for that session! In addition, he apparently did not mix the hydrogen peroxide and water before using the solution. That could be an added factor in the very short lifetime of the glow.
Like the previous posters I would strongly suggest that this either be prefaced by "DO NOT TRY THIS AT HOME" or by much more detailed disposal and protective gear instructions. Many municipal sewer systems have very strict limits on disposal of soluble chemical wastes, especially metals which can disrupt sewage treatment systems.
10.24.07 6:13 PM PDT
John H Nix
With a pH of 11.8 the solution is VERRY alkaline, almost as alkaline as Lye.
My question is what metals would you use for 1.)Red, 2.)Green, 3.)Orange, 4.)Yellow, or 5.)Purple?
10.24.07 8:48 PM PDT
carol
Real nerds protect their eyes! Put on your safety glasses and THEN I'll consider you cool.
10.25.07 6:17 AM PDT
Eliza
How much ammonium carbonate did you use? You do not mention this in the clip or transcript. Thanks.
10.26.07 7:18 AM PDT
JH
Kids watch this show. A 12 YR. old who is viewing it needs more safety info., and less comments about CSI and creepy people.
10.26.07 7:41 AM PDT
mikah
i agree w/ the first comment. why shouldn't we touch it?
10.26.07 9:14 PM PDT
Joey
I don't see what everyone is complaining about. He said specifically not to "throw on children". How much safer do you want?
10.27.07 3:12 PM PDT
Chuck
I used to do Hollywood special effects, and we once needed to create glowing rocks that could be passed around and carried in a basket. We cut open light sticks and separated the AB solutions, and when the camera was ready to roll, mixed the solutions and funneled them into clear acrylic "rocks" that we made, which we capped and rinsed. Worked great. Of course, we had full protection for eyes and skin, including goggles, rubber suits, rubber aprons & gloves, since the MSDS noted that contact with this stuff could cause testicular cancer.
10.27.07 6:57 PM PDT
TheGeek
I have to agree with alot that said above. The Hack segment was fun and I would like to see more of them in the future. But, it was majorly lacking. Not enough detail to do it yourself but enough detail and lack of safety instruction to make it dangerious for anyone who tries.
11.1.07 8:26 AM PDT
Iwan Evans
Why Dangerous To Put In Mouth???? All of them say they are NON - TOXIC!!! Stupid People....
11.1.07 8:32 AM PDT
Iwan Evans
Another Comment from me...
BTW: I got it on my skin, in my mouth and in my eyes (I chewed it!) Nothing happened - I washed my eyes out & i simply glowed for the rest of the night... GO GLOW STICKS!
11.2.07 2:17 PM PDT
Beverly Castner
As a research scientist, I find the demonstration to make a glow stick completely irresponsible! The demo seemed to indicate that you could do this at home! Mr. Hardwick should have been protective clothing (lab coat), protective glasses and gloves! Luminol is not a chemical that should be available to the public, who have no idea of how to deal with and dispose of it. In schools, universities, and research facilities, safety is the number one rule. There are lots of at home science experiments that can be done that are fun, teach, and are safe. If you are promoting science, do it properly. Safety first!
11.6.07 4:12 PM PST
Rick
There is no scientific evidence that shows that these chemicals are harmful or cause cancer. They say non-toxic for a reason, and you can throw them in the trash, like any other glowstick.
11.9.07 10:44 PM PST
TheGeek
Beverly Castner said:
"Luminol is not a chemical that should be available to the public"
WTF??? Luminol is no more dangerous then half the stuff found under the average American kitchen sink. In fast it's less of a health hazard then Drano, the MSDS for Luminol rates it's health hazard as a 2 while Drano is a 3.
Yes there should have been more safety info in the video but saying that Luminol is so dangerous that the public shouldn't have access is just fear mongering.
12.12.07 5:52 PM PST
RealitySetsIn
I see a lot of posts here about safety.
People are asking why they shouldn't drink something that is pH > 11. Come on now... don't do the experiment if you want to drink things you don't know anything about.
America is loosing Her creativity and ingenuity that once made Her great because Science is not taken seriously.
12.13.07 11:18 AM PST
SpidermanLozer
WTF?! i need to know how to make different colors...doing this 4 science fair!!!
1.9.08 3:44 AM PST
Euph0ria
If the chemicals that go into making glow sticks are so dangerous as many people here who have comment have made them seem, why is it that anyone, of any age, can purchase a glowstick and do whatever they like with them? It even reasonable to assume a fair number of these kids will rupture the containers, put the substance on their skin and or even inadvertently digest some of it. However, I have never ever heard of a single report of poisoning from a glowstick.
1.18.08 3:32 PM PST
zoey
cool my sicnce progect is going tro be awsome
2.3.08 10:28 AM PST
max
i just did this with a more consentrated solution and put it in a spray bottle, then i sprayed it on my shoes!!
2.24.08 9:34 AM PST
Hannah Schaefer
that is soooo cool.can you guys replay that movie.please
thanks.hannah schafer
3.25.08 11:50 AM PDT
sue
I think everyone needs to "lighten" up!!
4.15.08 10:45 AM PDT
milinda
where do you get the stuff at?
4.20.08 9:33 PM PDT
Tony
is there any clips or show or anything to prove it works
4.28.08 12:17 AM PDT
hana banana
u guys need 2 take a chill pill
5.21.08 5:01 PM PDT
shawn
Well...if copper sulfate made blue Im going to assume this worls the same as fire works.
Red - Strontium (strontium chloride or strontium sulfate)
Orange - Calcium chloride or calcium sulfate)
Yellow - Sodium
Green/Blue - Copper solutions can be used.
Purple I dunno.
6.22.08 10:16 PM PDT
Lab Tech
Potassium is purple.
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