What would be more insulating?

The aerogel particles would cost 45 dollars per 950 cc or in other words a little over 4 cups/32 oz (enough for 3 to 4 insulated bottles).  If i used aerogel, i would put a layer of aluminum foil in between the insulation.

How about several layers of carbon felt? It’s a pretty good insulator, and it’s light.

FYI,

With cylinders, there is a critical insulation thickness to consider.  Too little insulation and things warm up fast, too much insulation and you actually increase the thermal conductivity.  You need to understand all of the physical properties of your materials to optimize the results.  Here is a link to some of those calculations .http://www.reviewpe.net/penotes/heat_t/b5_3.htm.  Optimization of insulation of a cylinder is a not a trivial manner.  Maybe David’s students to solve it for us.

Hi Gary,  i don’t have any carbon felt on hand.  Not sure it would be as good as either foam i currently have.  I’m definitely tempted by the aerogel–since it’s 99.98% air by volume, it would weigh very, very little and is very, very insulating–next best thing to vacuum.  Thank you for the suggestion.

Interesting info Jon, thank you for sharing it.  Initial testing with a previous model, indicated pretty good insulation potential.  Boiling water was put in the bottle and then it was put in the fridge overnight and slightly over 8 hrs later, the water was about tepid.  That’s as good as some of my vacuum insulated bottles, but about half the weight for similar volume capacity.

This new bottle, will use a similar insulation thickness, but some different materials and slightly different design.