Why aerogels may take us to space

Silica aerogels and collecting stardust

Introduction to Aerogels

Aerogels are the lightest solid material in the world, with up to 99.98% air by volume. They are nicknamed ‘frozen smoke’. They currently have 15 Guinness World Records.

History

The term ‘aerogel’ was first introduced in 1932 by Samuel Kistler, an American scientist and chemical engineer, to describe gels in which the liquid had been replaced by a gas. Gels had been previously been dried by evaporation but Kistler used the ‘supercritical drying’ technique, which is still used to produce aerogels today.

Supercritical Drying

Removing all the liquid in a gel without changing the structure of it. This is done as follows:• Alcogels are

pressurized and cooled

• Liquid CO2• Heated and

pressurized• Slow release of CO2

Properties of Aerogel

•Density • 1.9 mg/cm3

• Tensile Strength• 16 kPa

Structure

Aerogels have a complicated, cross-linked internal structure.

Micropores = < 2 nm diameterMesopores = 2-50 nm diameterMacropores = > 50 nm diameter

Stress, Strain and Young’s Modulus

Young’s Modulus – 106 Pa

Insulation

"You could take a two or three-bedroom house, insulate it with aerogel, and you could heat the house with a candle. But eventually the house would become too hot."  - Dr. Peter Tsou of NASA's Jet Propulsion Laboratory

NASA’s Stardust Mission

• The main aim is to discover more about the origins of the solar system with cometary particles & interstellar dust.

• Relatively pure cometary samples can be obtained.

• These are useful because they are less likely to have cross-contaminated by neighboring bodies.

Tennis racquet shaped collector

Collection Problems:• Very high velocities

leading to damaged samples

• Tiny particles impossible to find on collection

Aerogel’s Solutions:• Sponge-like structure

provides safe, gradual stop for particles

• Transparency for ease of particle tracking

Future of Aerogels

X-aerogels

• Insulating skylights• Armor• Non-deflatable tires• Aircraft structural

components• Heat shields for spacecraft

re-entry

Bibliography

https://www.llnl.gov/str/Foxhighlight.htmlhttp://www.aip.org/tip/INPHFA/vol-10/iss-5/p26.htmlhttp://science.howstuffworks.com/aerogel4.htmhttp://www.youtube.com/watch?v=kHnen2nSmDY http://en.wikipedia.org/wiki/Aerogelhttp://stardust.jpl.nasa.gov/images/technology/aerogelhand.jpghttp://www.aerogel.org/?p=345http://www.aerogel.org/wp-content/uploads/2008/09/inorganicaerogels1.gifhttp://engineering.union.edu/~andersoa/Senior8.jpghttp://www.grc.nasa.gov/WWW/RT/2004/RM/RM11P-leventis.htmlhttps://www.llnl.gov/str/Foxhighlight.htmlhttp://thermablok.com/ http://stardust.jpl.nasa.gov/tech/aerogel.html http://upload.wikimedia.org/wikipedia/commons/thumb/1/13/Carbon_dioxide_pressure-temperature_phase_diagram.svg/220px-Carbon_dioxide_pressure-temperature_phase_diagram.svg.pnghttp://www.sps.aero/Key_ComSpace_Articles/TSA-009_White_Paper_Silica_Aerogels.pdfhttp://msnbcmedia1.msn.com/j/msnbc/Components/Photos/040421/040421_aerogel_torch_bcol5p.grid-4x2.jpg

Aerogels Handbook – Michel A. Aegerter

The unbeatable lightness of aerogels: Take 10 parts of metal oxide, 90 parts of air, mix well - and watch industry fall upon the product with glee – New Scientist - 1993