Aerogel is a synthetic porous ultralight material derived from a gel, in which the liquid component of the gel has been replaced with a gas. The result is a solid with extremely low density[1] and low thermal conductivity. Nicknames include frozen smoke,[2] solid smoke, solid air, or blue smoke owing to its translucent nature and the way light scatters in the material. It feels like fragile expanded polystyrene (Styrofoam) to the touch. Aerogels can be made from a variety of chemical compounds.[3] Aerogel was first created by Samuel Stephens Kistler in 1931, as a result of a bet[citation needed] with Charles Learned over who could replace the liquid in "jellies" with gas without causing shrinkage.[4][5] Aerogels are produced by extracting the liquid component of a gel through supercritical drying. This allows the liquid to be slowly dried off without causing the solid matrix in the gel to collapse from capillary action, as would happen with conventional evaporation. The first aerogels were produced from silica gels. Kistler's later work involved aerogels based on alumina, chromia and tin dioxide. Carbon aerogels were first developed in the late 1980s.[citation needed] Aerogel does not have a designated material with set chemical formula but the term is used to group all the material with a certain geometric structure.[6]

1. RECENT TRENDS IN CHEMICAL ENGG.
AEROGEL

2. WHAT IS AN AEROGEL ? ? ?
• AEROGEL is essentially the solid
framework of a gel
• A class of porous, solid materials that
exhibit extreme material properties
• A Nanostructured Material with Fascinating
Properties and Unlimited Applications

3. HISTORY OF AEROGEL
 Aerogel was first created by Samuel
Stephens Kistler in 1931.
 The first aerogels were produced from silica
gels. Kistler's later work involved aerogels
based on alumina, chromia and tin dioxide.
Carbon aerogels were first developed in the
late 1980s.

4. PROPERTIES:
 Extremely low density
 Very good thermal
insulator
 High specific surface
area
 Lowest dielectric
constant

5. PROPERTIES:
 ultimate compressive
strength, compressive
modulus.
 flexibility, modulus of
flexure.
 Water proof material.

6. TYPES OF AEROGEL
 On basis of Material
 Silica
 Metal oxide
 Carbon
 On basis of
temperature
 Cryogel - for low-
temperature applications
(-200°C - 90°C);
 Spaceloft - for mid-
temperature applications
(-200°C – 200°C);
 Pyrogel - for high-
temperature applications
( up to 650°C

7. SILICA AEROGEL
• high specific surface area (500–1200 m2/g)
• high porosity (80–99.8%)
• low density (∼0.003 g/cm3)
• high thermal insulation value (0.005 W/mK)
• ultra low dielectric constant (k= 1.0–2.0)
• low index of refraction (∼1.05)

8. METAL OXIDE AEROGEL
• Density 0.070 g cm-3
• Surface area 340 m2 g-1
• Pore volume 1.25 cm3 g-1
• Average pore diameter 12 nm

9. CARBON AEROGEL
 Carbon aerogels are
composed of particles
with sizes in the
nanometer range.
 covalently bonded
together with pore
diameter under 100
nm.

10. APPLICATION IN SPACE RESEARCH
 Thermal insulation for
planetary landers and
rovers
 Insulation of cryogenic
propulstion system

11. AEROGEL AS STAR DUST COLLECTOR
 a section of aerogel as
part of its Stardust
probe to collect
samples of material
from the tail of comet;

12. GENERAL FIELDS OF APPLICATION
 Hydrogen storage
 Magnetic media
 An excellent sound
insulator

13. GENERAL FIELDS OF APPLICATION
 daylight panels.
 Insulation of windows
and sections of the
roof.
 As water proofing
agent.

14. REFERENCE
 www.aerogel.com
 John F. Poco, Joe H. Satcher , and Lawrence ,
Synthesis of high porosity, monolithic alumina
aerogels, Journal of Non-Crystalline Solids, 285,
57-63 (2001).

15. THANK YOU