Aerogel - Super Insulator, Super Sponge

Difficulty of Project

Easy to extremely difficult

Cost

At the easiest, less than $10

Safety Issues

None unless a very advanced student attempts to build a “critical dryer”

Material Availability

Easy to get photos, etc. Slightly difficult for basic materials. Almost impossible to get actual aerogel.

Approximate Time Required To Complete

Variable

Objective

Aerogel is the lowest density solid known, and has been called “frozen smoke.” It has been used as an insulator, and also as an outer space sponge to collect dust and gases from comets in NASA’s Project Stardust. Explore why NASA used, and is using, aerogel for the Stardust project. Learn about other uses (i.e., insulation) of this substance.

Materials and Equipment

Samples of the actual foam are difficult to find. However, the pellets used to make the foam is readily available. Other forms of aerogel, such as insulation, are also fairly easy to find as part of the display.

United Nuclear - Scientific Equipment and Supplies

Thermablok: The 21st Century Revolution in Aerogel Building Insulation

Introduction

Aerogel is a very unusual substance. It has the lowest density of any known solid and is almost “light as air.” Yet if you put crayons on top of a piece of aerogel and a blowtorch beneath, the heat won’t get through. This makes it a superb insulator.

Another property is friability. Think of a standard air filter made from fiberglass or foam. Dust and other particles are captured, but mostly they are merely blocked. Aerogel will almost shatter and collect particles inside. (Think about tossing a tiny pebble into cotton candy to get the idea of how aerogel was used to collect comet dust and particles.)

Project Stardust was conceived. The goal was to send a probe into the tail of a comet, collect the dust and gases, and bring them back to earth for study. Panels of aerogel were tucked inside the probes. Once in the tail of the comet, the panels would unfold, collect the samples, then fold back inside the probe which would then return to earth.

Photos

NASA has many photos of the Stardust project.

Concepts

NASA needed an extremely lightweight substance that could also act as a “sponge” to capture physical particles from the tail of a comet and then bring that back to earth for study. Aerogel was chosen for this mission.

Research Questions

• Who was Samuel Kistler?
• What is silica dioxide?
• Why is aerogel so light in weight and density?
• How does the Stardust Project use the properties of aerogel?
• How else is aerogel being used?

Terms

• Supercritical Drying: the process of replacing fluid with gas, somewhat similar to freeze-drying
• Gel: a semi-fluid
• Friability: the tendency to shatter
• Amino Acid: a basic building block of life

Experimental Procedure

Except for an advanced (high school) student willing to build a supercritical drier, there is no actual procedure. Instead, the student will show with illustrations how the process is done, and the results.

Bibliography

1. http://en.wikipedia.org/wiki/Aerogel
2. http://unitednuclear.com/index.php?main_page=product_info&cPath=16_17_69&products_id=89
3. http://www.aerogel.org/
4. http://stardust.jpl.nasa.gov/photo/aerogel.html
5. http://eetd.lbl.gov/ecs/aerogels/aerogels.htm