Overview of Making Aerogels

Making aerogels is not only exciting from a technology perspective, it’s also a lot of fun.  Here’s a general overview of the process and what it takes.

The General Process

Generally speaking, making aerogels goes something like this:

  1. Identify what kind of aerogel you want to make
  2. Find a procedure (“recipe”) for making that kind of aerogel
  3. Mix up a bunch of chemicals in beakers
  4. Pour the mixture into a mold and wait for a gel to set
  5. Soak the gel under pure solvent to purify the gel and allow it to strengthen
  6. Depending on the procedure, you might also soak the gel in solutions containing functionalizing agents such as waterproofing agents or crosslinkers
  7. Solvent exchange the gel into the appropriate solvents by soaking
  8. Dry the gel, either supercritically or evaporatively, depending on the recipe

First Things First:  Read Up

Before diving in and trying to make aerogels of your own, you should really know more about what you’re doing and why you’re doing it.

Look around the Learn section of Aerogel.org and read up on basics like how aerogel is made and specifics about the flavor of aerogel you want to make.  Also take a look at the silica aerogel page to get a sense for how sol-gel chemistry works.

Stuff You’ll Need

Things you’ll need:

  • Chemicals (depending on your recipe)
  • Solvents used in most aerogel recipes
    • Ethanol or methanol
    • Acetone
  • Beakers, jars, or some other sort of general mixing glassware, or chemically compatible plasticware (polypropylene is usually pretty safe)
    • Covers for your glassware
  • Molds of some sort (beakers and test tubes work great)
  • Stuff to measure liquids with, such as:
    • Graduated cylinders
    • Graduated or volumetric pipettes
    • Syringes
    • A scale
  • If you need to weigh solid chemicals, a scale with 0.01 g resolution
  • Some empty bottles you can store your chemical waste in
  • A ventilated working space
  • If you are going supercritically dry your aerogels, a supercritical dryer
    • Liquid carbon dioxide tank
    • Accompanying supplies

and of course

  • Safety goggles
  • Closed-toe shoes
  • Disposable gloves
  • Someone to supervise you if you’re under 18, or someone to check in on you if you’re over 18

Costs and Being Resourceful

Aerogels are not inherently expensive materials to make once you have all the stuff you need and know what to do, but getting set up might take some money.  That said, you don’t need to spend $500 on glassware when you can spend $10 at the grocery store and find stuff that will work just fine.

On Aerogel.org you will also find designs for low-cost supercritical dryers that can get you making aerogels cheaply and safely relatively easily.

Planting Seeds, Being Persistent, and Being Patient

Most of the processes involved in making aerogels require a lot patience because they involve gel times that can take several hours and multiple diffusion-limited solvent exchanges that require several days.  It’s important to be persistent but patient in making aerogels.  On the flip side, you can stagger the start of lots of experiments and find yourself continually delighted that things you walked away from have gelled or are now ready to work on again.  Think of it like planting seeds!

Aerogel production requires multiple steps where you have to wait for a long period of time that have to be done in order.  While most of the steps in aerogel production can be left for longer amounts of time without consequence, but remember if you aren’t persistent and don’t keep moving things forward, nothing will get done!

That said, it is also really important to be patient and to give enough time for each step to be complete (that is, you make sure your gels have enough time to fully set, that you age your gels, and that you adequately perform all solvent exchanges).

And trust us, being patient makes the difference between being successful and continually being frustrated with poor results.

Additional Advice

Don’t be afraid to seek out help if you need it.  There’s lots of resources both on Aerogel.org and on the Internet for helping you find people that can give you advice on doing chemistry.

Also be sure to read through the other articles in the Getting Started section and to take your time.  Aerogels take a lot of time and practice to make.

Comments are closed.