Out of curiosity, are there any HNers that know much about Aerogel and the chemistry or physics of it to answer the following question:
Aeorgel is an amazing insulator from heat due to its incredible surface area of its glass-foam-like structure that it can withstand immense heat with very little mass.
If one could make little balls of hydrophobic aerogel - then mix those balls with water - could you get a greater cooling/insulative effect from the water -- for use in something like a reactor?
Obviously there are problems with this. 1) Aerogel is normally destroyed by water, 2) you may have to regularly replenish the aerogel balls in the water which, also, due to the deterioration of the aerogel balls in the water, itself, destroy the insulative effect/taint the water. 3) Aerogel may not react very well to being irradiated...
So, barring some technical details - is it conceivable that insulated water could be made?