A nice groups work about the insulation of a thermos with only recycled materials was done at Rutgers School of Engineering by Kahyee Fong, Damin Hashash – Gabe Kooreman, Crystal Mckenzieand Elaine Wang . I give the abstract hereunder:

The goal of this project was to take advantage of the capabilities of nanotechnology by using the room temperature sol-gel process to form a
silica nanofoam composite with a common household foam, in an effort to synthesize a cheap, lightweight insulator for use in a thermos. Through testing of hybrid insulators, it was determined that a silica nanofoam and packing peanut composite combines the natural insulating properties of the packing peanuts and
of the silica nanofoam to make an insulator for a thermos.

With a smart comparative and low cost thermal conductivity measurement, they were able to get the following list.

This is not direct a cellular glass subject but I simply liked the work and I was surprised by the results.