The Story of Aerogels: The Power of Porosity

I apologize for the narration of The Mat Sci Guy. His voice certainly lacks those nice, pear-shaped tones that are so valuable on the radio - or maybe he just needs a better microphone or a decongestant or processing software.

But...his content is interesting and educational, well laid out and thoroughly researched, so I recommend watching the video but maybe not showing it in class.

Today's video sees him exploring the formation, properties, and applications of aerogels in their various forms. 

I'm thrilled that I know something about sol-gel chemistry from a summer of research I did at Miami University some twenty five years ago. I wasn't making aerogels, but I did spend the summer making sol-gels and exploring their applications in chromatography columns. 

I also have a little experience with aerogels...or at least I did until my favorite coworker shattered my large sample. Now I have multiple, smaller samples.

Flamethrower vs Aerogel

They killed that poor kid's flamethrower.

That sucks.

Dr Derek got himself some big sheets of aerogel and stood behind them while a makeshift flamethrower went full bore at the sheet from barely a feet or two away.

I think aerogel might be a pretty good insulating material.

I may need to get myself some of that stuff...and not to let Rebecca get ahold of it.

To me, the demonstration after the blow torch - around 6:20 or so - is more impressive. Dr Derek touches a piece of metal that is mostly coated with a 1mm thick layer of aerogel. The coating is at 125 C, hot enough to boil water. Dr Derek then rests his hand on the aerogel coating without harming himself - because the aerogel does such a spectacular job of not allowing the thermal energy to be transferred to his fingers.

He also shows a few other commercial uses of aerogel to keep really cold things really cold - like pipes carrying liquid natural gas in industrial settings...and deep undersea insulating oil pipelines.

My closing take-away is that this stuff is miraculous.

World's Lightest Solid!

I've written about aerogel before (and perpetually mention the demise of my one piece).

But I haven't shown a video that uses a FLIR camera (1:00) to show the heat zones as they insulate a chocolate bunny from a bunsen burner using aerogel, where they show the industrial process of making aerogel (5:25), or especially where you actually get to see a supercritical fluid through the window (6:25 - the absolute highlight for a teacher who used to teach phase diagrams in AP chemistry), or where you get to see a mid-process 'wet' aerogel filled with alcohol (4:50).

If you happen to follow both of my blogs, you might see this double posted because of that supercritical fluid bit.

Seriously, Rebecca, you'd have my heart if you bought me some new aerogel.

Making silica aerogel at home

I've mentioned my lack of success with owning aerogel before. I can't even imagine what it would take to make some of my own - nor how awesome it would be to do so.

Yeah, this video goes through the process step by step, but it also uses a bunch of chemicals and equipment that I very much don't have.

Cool to see, though, just how aerogel is made.

Strong, machinable aerogel now available

I had a piece of areogel. It was identical to the piece of 'classic silica aerogel' that the video shows at 0:20 in the video above.

The Becky Heckman got ahold of it.

Then I had a whole bunch of pieces of aerogel. That stuff is incredibly fragile.

 Must be Italian.

I want Rebecca to buy me a piece of airloy to make up for her lack of delicacy.

Will you sign my petition to get Rebecca Heckman to buy me a piece of airloy? If so, please click the link.

10 mind-blowing man-made materials

Admit it, you're every bit as susceptible to list videos (and internet posts) as I am.

We all must be, otherwise we'd probably lose a third of the internet and be left with just cat videos and pictures of pretty people.

This video is severely lacking in detail for each of the "ten mind-blowing man-made materials", but it would be a great starting point to get your class thinking about the Materials Choice Award.

Red Hot Nickel Ball Has Finally Met Its Match!

You might not have been know that Red Hot Nickel Ball has its own YouTube channel, but it does.

Well, almost. RHNB has its own playlist of thirty-two videos from among carsandwater's uploaded videos.

Things all got started with a mute, never-appearing user putting the eponymous red hot nickel ball into a cup of water (a demonstration that I love doing - with slight adjustments - in class when I'm introducing thermochemistry in chemistry class) and continues through honey, pop rocks (surprisingly cool to watch), a steak, and - most recently - aerogel.

Man, aerogel is cool.

I wish I had some.

Wait, I did have some.

Until another master teacher broke it.

Which makes me sad...

Graphene aerogel is the new world's lightest substance

As research into aerogel continues, scientists are discovering ever-lighter variations. First, there was carbon nanotube aerogel, with a density of 4 milligrams per cubic centimetre. Then along came silica aerogel, which weighed in at 1 milligram per cubic centimetre and garnered 15 entries in Guinness World Records. It was ousted by metallic microlattices, at 0.9 milligrams, and then aerographite, at 0.18 milligrams.

Now, a new graphene aerogel created by scientists led by professor Gao Chao at the Zhejiang University has swept past, weighing in at just 0.16 milligrams per cubic centimetre

The original article is from Nature, but only an abstract is viewable online for free, sadly. The full article takes a little bit of money that I'm not willing to spend ($8 for the one article or $199 for a year's subscription). Luckily there is a decent enough report on CNET Australia's blog (the source of the above quote).

Aerogels are odd, weird substances. I have a piece in a plastic container that I've taken out a few times to hold it. Each time it feels like I'm holding a solid and a gas at the same time. It's a contradictory feeling, a real-life discrepant event without a trick. The aerogel that I have - now snapped in two by another ASM master teacher, arggh - is a silica aerogel (available from Educational Innovations, one of our summer camp sponsors) which means it's something in the order of six times more dense than is this new graphene aerogel.

I, of course, want some of the new stuff.

Because it's the newest...

PS - There are other possible sources for the purchasing of silica aerogels - United Nuclear (small pieces in semi-bulk only), ebay (including, as of today, a huge 220cc sample), ThinkGeek, and BuyAeroGel.com.

FYI: What's the lightest metal on Earth?

If you answered 'any lump of metal somebody else is carrying,' then you're sarcastic.

If, on the other hand, you answered 'metallic microlattice,' I'm thinking you probably already watched the video.

The challenges of materials science often boil down to some combination of 'make it lighter, cheaper, stronger.' Cut down the material's weight, and we can cut down the cost to ship it, to fly it, to make it, to throw it away when we're finished. Make the material stronger, and we can use less of it for a longer time and can push harder with or on it.

It seems that every time we start to think that we can't make strong materials from less material, somebody comes along to prove us wrong. According to a Popular Science post...

The key structural component is a series of hollow tubes. In a study published last November in Science, the researchers exposed a light sensitive liquid to UV light through a patterned mask, which created a three-dimensional photopolymer lattice. They then deposited a layer of nickel-phosphorous onto the polymer lattice, which was then etched. The remaining structure was a macroscopic material with hollow tubes as the base structural elements. The resulting material had a density of .9 mg/cm³. By comparison, ultralight silica aerogels are 1 mg/cm³.

I've held aerogel. I've let another ASM master teacher (cough-Becky-cough) break my aerogel, and to think that this material is lighter than aerogel is pretty impressive.

I'm putting the video after the jump because it auto-plays. Click through to watch.