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Why aerogels may take us to space. Silica aerogels and collecting stardust. 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. Introduction to Aerogels. - PowerPoint PPT Presentation
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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in 1932 by Samuel Kistler, an American scientist and chemical engineer, to describe gels in which the liquid had been replaced by a gas.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