Tuesday, March 13, 2018

Don't drink the colloid

Last night Andrew put on some special lotion with colloidal oatmeal in it to help soothe his raw, cracked hands (it's so dry here).

"Mmmm...I have oatmeal on my hands," he said, as if to rub it in (whoa—no pun intended).

"So, you used the regular lotion?" I asked.

"No. I used the special stuff."

"The regular stuff is made with oatmeal, too."

"No!" he said, shocked. "Really?!"

"I think so," I said. "Aveeno—it's made from oats."

"Well, that would explain the picture of oats on the bottle," he said.

We looked at the ingredients and found that, yes, Aveeno is made from oats (and, in fact, is named for oats: Avena sativa). So that's fun. Aveeno contains "avena sativa (oat) kernel flour" while our special lotion (Neosporin's eczema essentials) contains "colloidal oatmeal."

As soft scientists, and hobby chefs (Andrew basically worships Kenji), we're pretty confident about what flour is. But, uh, colloidal oatmeal? What is that?

"Colloid is, like, a scientific term. Like, for chemistry, I think," Andrew said.

"Sure," I agreed because I had no idea. "I mean, I've heard it before. My grandma used to have me put colloidal silver on my warts."

And apparently it works because my feet have been wart-free for, like, two decades now. So.

Andrew definitely had more of a clue than I had about what a colloid is—I do not recall ever hearing that word uttered in school—but we still had to look it up.

So, basically, a colloid is a mixture, where the particles being mixed in are too small for the naked eye to see but are much bigger than the particles in, say, a solution. So the particles don't get dissolved. Rather, they are suspended—and they don't settle.

If you ground up oatmeal into a fine powder and then mix that powder into water, the oatmeal wouldn't dissolve (like sugar or salt) but you wouldn't be able to see little chunks of oatmeal floating around (because that would be a suspension). Instead it would just make the water cloudy.

Something like that. You can make colloidal oatmeal at home. And that must be what it means when people say to soak in oatmeal—like, to treat diaper rash. I've always been like, "Nope. Nope. Nope. You can't bathe a child in oatmeal."

But apparently that's because I'm a barbarian who doesn't know what colloidal oatmeal is.

And so it happened that we were still talking about colloids when we went to bed (trying to really solidify the principle and figure out what exactly a colloid was because, I mean, I got it but I didn't really get it, if you know what I mean). We could think of examples of solutions and we could think of examples of suspensions but...colloids?

"Okay, so for a colloid, the particles have to be equally distributed and you can't see that they're there and they cloud the liquid, but they don't dissolve because they aren't soluble..."

"Is Kool-Aid a colloid?" I wondered. "You can see it in the water after it's mixed in, but not the individual particles. Like, the water turns red, or whatever. I dunno..."

"Kool-Aid a colloid," Andrew snickered. "That's funny."

"Maybe, maybe," I began theorizing. "Maybe Kool-Aid is actually named after colloids. I mean, you've always just thought it was Kool as in fun and super sugary. But what if it's actually Kool as in colloidal. Kool-Aid could be a much nerdier drink than you've ever imagined."

"That should be their new tagline. Kool-Aid: much nerdier than you imagined."

Of course, the fun stopped there because we had to find out the truth about Kool-Aid and, as it turns out, it's not remotely nerdy. It's just super sugary fun. Kool-Aid is actually a prime example of a solution. The water turns colour, but light still passes through. To be a colloid, the water would have to turn cloudy (or otherwise opaque).

So, now that you're wondering (unless you aren't because you already knew what a colloid was), common examples of colloids are: mayonnaise (and other emulsified foods—like, whipped cream, which is cream emulsified with air (I'm pretty sure)), blood, milk, and things like colloidal silver and colloidal oatmeal (obviously). Ooh—when you mix cornstarch and water. That's a colloid, too.

PS. We joked about some chemist having a blog called "Don't drink the colloid," but, alas, that doesn't seem to exist. Probably because Kool-Aid isn't a colloid...which makes the joke a whole lot less funny.

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