I Waterproofed Myself With Aerogel!

I feel confident.

"You're confident that I am NOT gonna be damaged? Not permanently? Okay, let me back up for a moment. I want to talk about the properties of aerogel, the world's lightest solid. What I'm gonna do is I'm gonna lean in so it's coming in through this mic, and then can you do that again? Yeah, this is what it sounds like. That is weird; it has a metallic ring. First recognized by aerogel's inventor, Samuel Kistler, all the way back in 1931.

Now, aerogel is an excellent thermal insulator, but it's not the easiest material to work with.

"Can I try it? Sure. Oh, I didn't... I don't quite have the touch. Oh, I can't? I make it ring? Oh no, look, it didn't take a whole lot to break it, right? It breaks pretty easily. So is there a way to take the extraordinary thermal insulation of aerogel but make it more usable? What I put together here is just a combination of aerogel particles, silica aerogel particles, and a non-flammable binder. You should be able to put it on your skin and hit yourself with the torch, right?

"I'll give it a shot. Okay, so you just take a little bit and squeeze it around your finger. Just around? Yeah, just squeeze it around here. One finger, two fingers. You want? Matter how’s that? Am I doing it?

"Oh yeah, that's... yeah, I'll be good. Just wanna make sure the fire, when it goes around your finger, doesn't hit the Bearskin. Seems like it's pretty thin around this fingertip here. Like, how thick should it be? You're making me nervous holding a blowtorch. Can I do the blowtorching, or you can do the blowtorching? Absolutely, because I mean, if this goes wrong..."

"So how hot is a blowtorch flame? Well, it's really hard to tell, but from our experience, it's usually, you know, at least 1500 degrees C and can get as hot as 2000, so yeah, this is very hot. Alright, let's try it.

"This is so wrong, that little jittery pot there. I, you know, it looks like I'm toasting a marshmallow. Whoa, why is it flaming like that? And what is burning? Binder right now, correct? Should people just hold the rate on there? It doesn't feel hot at all. My finger does not feel hot at all.

"That is insane right there! Proprietary! I cannot believe how a little warmth I feel passing through that. The FLIR 10 2013 temperature ranges, and here the aerogel is clearly hotter than the 160 degrees Celsius upper limit. I mean, it's glowing orange hot, so it's clearly incredibly hot. I mean, if you can see the black body radiation, you know that it's very hot.

"So we went to the highest temperature range. So this goes up to 2000 Celsius. 881, 907, 907, 907 degrees Celsius? That is absurd! Pretty good, right in front of my finger. What? So this was about almost a thousand Celsius, but behind this thin layer of aerogel, my fingers are just warm!

"Wow! I mean, it is clear this stuff insulates. This video is about taking aerogels' extraordinary properties and improving on them. For example, I'm about to step into this pool without getting wet. There's a layer of air there right next to my skin. That thin layer of air is what makes my skin look silvery light from certain angles. It reflects off the water air interface in what's called total internal reflection. That is very strange; this is a really cool effect. I mean, just besides the fact that I'm basically waterproof, I feel like this extra air on me is making me more buoyant than usual.

"Let me try coming out by the water and see if I'm still dry. That is true! I don’t really feel wet at all. That was weird! Really weird!

"So how did I make myself waterproof? I did it with aerogel particles by taking a bucket of them and coating myself with the tiny best. But this is a kind of strange way to become waterproof because normal silica aerogel is hydrophilic.

"There we go! Now this is a hydrophilic aerogel, so all those OAH groups inside the aerogel are absorbing the liquid and causing the aerogel structure to collapse. Aerogel is really good at absorbing water for two reasons. First, it contains a lot of surface area due to its nanoscaled sponge-like structure. An ice cube-sized piece of aerogel contains half a football field of surface area. That makes it good at absorbing lots of molecules, something scientists have sought to exploit.

"My favorite application, which I still think today is a good idea, is... what's the idea? Is a physical insecticide? So most insecticides work by being neurotoxins. They're called cholinesterase inhibitors. It's the same mechanism as nerve gas, and we spray this on crops and things. But a physical insecticide works by basically getting stuck to the outer skin of the insect and basically sucking all the moisture, or the oils, out of them to the point where they just sort of dry out to death. It's kind of like putting salt on a slug."

"Yeah, that's a very good analogy, exactly. The other reason it's good at absorbing water specifically is because its structure is covered with OAH groups, which attract water molecules, and that makes it ideal for use in museums.

"In the past, I've been working with a company in Italy called Opium, which makes museum cases. I mean, they made the case for Mona Lisa. They are interested in putting aerogels in the cases because it's a passive moisture regulator. Essentially, once you have it inside, if the moisture increases, it absorbs a lot of it. If it decreases, it releases some of it.

"Aerogels' ability to absorb is even being used right now to help detect Mars quakes. These were the ones that were made for the NASA InSight mission. This aerogel looks like chalk because so-called zeolite particles are dispersed throughout it. They can absorb moisture even at very low pressures. There's a seismometer that contains three small seismometers, and since they're so small, they require exceptional vacuum inside; otherwise, the motion gets stamped.

"So that's what we developed this for. The zeolites were helping absorb the moisture predominantly that was coming off of the hypotheses and gave me some gassing, different things. So that is, it's sort of maintaining the vacuum by keeping - pulling things. It's actually a vacuum ball if you think of it that way, and what's interesting about it is it does not require any power, any consumptions.

"Very light, so essentially this is what enabled the InSight mission to work. Aerogel can absorb up to 25 times its weight in water. But for some applications, this is less than ideal. So once we've done this, is that piece of aerogel ruined now?

"Pretty much, yeah. That's entropy, irreversible damage there. To counteract this issue, we take a hydrophobe; it's a reactive chemical that when it touches an OH group spontaneously rearranges with that OH group and creates this big non-polar group and that repels water.

"So by replacing just 30% of the OH groups that line the inside of the aerogel with these hydrophobic groups, you can make an aerogel that perfectly repels water.

"So here, water bounces off. It's totally impervious; it does not penetrate in, and it can sit on water for months, and it will be just the same as if it was never wetted at all. You ready?

"I guess, let’s go. Shot! There it goes; it feels funny, 'cause it like hardly feels like the water is touching me because in a way, the water isn’t touching.

"It's not touching you! That’s what's amazing. At the molecular level, it is being repelled! Look how crazy that is! It's like a weird laminar flow. This is so trippy.

"So aerogel can be made impervious to water or more adsorbent. It is naturally brittle, but it can be worked into a sticky paste. And so far, I've really only focused on silica aerogel, but aerogels can be made out of all sorts of different materials.

"So all of these materials are nano-structured? That's right, and they have nano-sized pores around 20 nanometers in size? That's right; and they are over 50% air, correct?

"Which is why they're also lightweight! Yeah, some of them are made of polymers, and there is a trade-off between thermal and mechanical properties. A traditional silica aerogel is typically around 15 milliwatts per meter Kelvin thermal conductivity; so that means about 3 times, 2 to 3 times better insulating than styrofoam.

"These materials would be between one and a half to two times more insulating than styrofoam; somewhere around 20 to 26 milliwatts per meter Kelvin. This is a polyamide aerogel. This chemistry came from NASA, so it's a great insulating material, but it's not flammable."

"Knock on it; it feels like wood!"

"Internally, we call it Martian tape. Another way to make aerogel more workable is to incorporate it into composite materials, like blankets. Something that's in between silicon and silica. That feels nice; it feels very nice, doesn’t it? Feels like almost like a stuffed animal.

"Yeah, exactly! So this is a new type of aerogel blanket that in the future, we may find in something like an astronaut suit, or maybe even apparel.

"What this material is, actually, it's fiberglass. It does feel like it's a fiberglass that's been infused with aerogel. So that fiberglass aerogel composite, because aerogels are traditionally very fragile, by positing it with the fiberglass allows you to make something that can be flexed and cut and sewn and wrapped. It's not the most cuddly; it sheds dust when you tap on it, but go ahead and dust."

"Is that...? That's silica aerogel, the morphous silica, and it's very safe!

"It's not, for example, like quartz fiber or asbestos, which are, you know, long aspect-ratio fibers that the body has no chemical means or physical means of breaking down. This stuff is readily captured and expelled by the body, and it's not dangerous.

"And this is what they use to insulate subsea oil pipelines and refineries and all sorts of applications. So just that thickness will insulate a pipeline?

"Yeah, so that thickness, that one, this is one centimeter thick. In one centimeter, you get the same effective insulation value as three centimeters, over an inch of mineral wool or fiberglass by itself. So it's a tremendously better insulator.

"This blanket is actually what I'm gonna put to the test in the final episode of the aerogel trilogy, so subscribe if you don't want to miss it."