Making silica aerogel at home

Getting the TMOS is difficult since chemical suppliers are generally unwilling to sell to individuals.

The process to make aerogel is:

1. Mix TMOS, methanol, and ammonium hydroxide. Pour this mixture into molds, and wait for a gel to form.
2. Submerge the gel in methanol, and wait a day for the remaining water in the gel to diffuse into the methanol.
3. Discard the methanol, and replace with fresh methanol. Wait a day, and repeat. Repeat this process a few times over three days.
4. Transfer the gel into the supercritical drying chamber, and fill the chamber with methanol.
5. Add liquid CO2, then open the chamber's bottom valve to remove the methanol. Make sure the gels are always covered with liquid CO2.
6. Wait a day for methanol to diffuse into the liquid CO2.
7. Open the bottom valve and remove more methanol.
8. Repeat the methanol draining procedure while making sure the gels stay submerged in liquid CO2. Repeat the CO2 draining/exchange a couple times over 2-3 days.
9. Raise the chamber temperature to cause the CO2 to become supercritical. Slowly vent the chamber while applying heat to ensure the CO2 moves from the supercritical phase to the gas phase. Continue venting the chamber slowly, then remove the finished aerogels.

[StevePelcz]

Dude just invited half a million people to come over and make aerogel at his shop, what a baller.

[yesterman]

My home doesn't look like that at all.

[Alexander_Sannikov]

Even though this guy does not taste his chemicals as often as Cody does, he's still pretty interesting to watch.

[billsmathers]

Not sure if you're still checking comments on this video, but there's actually a semi-OTC method to make tetraethyl orthosilicate at home, which should substitute well for the tetramethyl used here. To do this, first prepare silicon tetrachloride by passing dry chlorine gas past some silicon in a heated tube. This reaction is extremely dangerous due to the large amounts of toxic corrosive chlorine required, but there are videos of the synthesis in youtube. One the silicon tetrachloride is made, purify it by passing it through a cotton filter and add it to excess anhydrous ethanol SLOWLY. The reaction is extremely violent due to flash boiling of the solvent. Once all the silicon tetrachloride is added, distill off the residual ethanol and what remains is tetraethyl orthosilicate, pure enough for aerogel.

[Niles_Champagin]

i think your definition of "at home" is slightly skewed

[caspernyholmlarsen]

>making silica aerogel at home
>you need tetramethyl orthosilicate and a super critical drying champer

Pick one

[cyrex]

I had my doubts when you first talked about doing this, but wow it's amazing what an individual can pull off. I've only seen areogel once, at an art exhibit, it was a nice big chunk of it too. It really does look exactly like smoke.

[protonus]

I never fully understood the production of aerogel until this video. Thank you for explaining this in a way I could grasp fully.

[shafransky]

one thing that may help against cracking. I believe you were right about the large almost instantaneous change in temperature being the cause for cracking. that being said, as opposed to wrapping the aerogel in foil, which will still allow the fluid to come in direct contact with a warmer body. I was thinking if you slowly cooled the gel prior to putting it in the chamber by putting the methanol bath in either a ice bath, or even just putting it in the freezer for a day prior to the supercritical phase. i belive this should help prevent cracking more so than just putting some foil around it.

[eddiebernays]

this guy reminds me a smarter more sane version of codys lab

[Cnctrldotcom]

Great video, I've fancied having a go at making areogel for a while. I don't want to sound like a health and safety freak but a gas mask doesn't offer sufficient protection. Moisture in the air and your breath will rapidly deactivate the filter rendering it useless at stopping chemicals. Why don't you build yourself a fumehood and vent it out one of the windows? A sheet of perspex a a couple of sheets of ply is all you'd need.

[bodiddly]

Your videos are an education.Thank you so much for sharing your projects with us.
You could avoid the multiple methanol changes by adding some anhydrous aluminum chloride granules to the Ethanol. These would lock up all the water that emerges from the gel.
Best regards,
David Kane.

[realvanman]

Wow, I hadn't realized how involved it is to make aerogel. It looks like my dreams of insulating my bus conversion with are dashed LOL!

[ichwillnurkommentierennixw]

Hey man, I´m just preparing a short scientific lecture about aero gels and your video gave an nice look about howto produce them without industrial ressources. Thanks for it.

[IgnemFeram]

I was thinking about making some at my home to help insulate my sun room (it gets cold in the winter and wreaks havoc on the electric bill) but now I see it would be cheaper just to buy a door because I don't have the equipment, chemicals, money, or know-how to make it. Cool video though.

[thorargent]

To get around the cracking issue, it might make sense to insulate and refrigerate the chamber first. You could even do that with a dry ice and alcohol bath without too much trouble. Once the gel is cooled, it will no longer undergo any thermal expansion or contraction of a significant scale. Then the addition of liquid CO2 will very likely not cause the cracking to happen. Just a thought.

[MatthewLe]

Instead of drying the gel by replacing the methanol have you considered adding a drying agent to it such a silica gel or anhydrous magnesium sulfate to essentially trap the water as it diffuses out of the gel into the methanol, then instead of changing it every day or so just leave it in the 1 container for a few days in the same methanol + drying agent bath.

[mainemoose]

During the water extraction phase perhaps you could use a desicant like CaO, CaO3, or silica gel to the dry gas instead of changing it out just sprinkle a little more in over time.  The desicant can be regenerated with heat (lots for CaO, CaO3), silica jell can ge cooked out in an oven.

[Larwood.]

TMOS is hard to get because it's very dangerous in untrained or malicious hands. Even a small amount of the vapor getting in your eye will cause blindness.

[johnqpublic]

I got to play with some aerogel in highschool back in 2003. A research physicist at OU brought it by. He also brought some metal wire that had true shape memory that could be reset by a quick dunk in room temp. distilled water.