Is it possible to cast CO2?

A lunch-time conversation with a friend has got me wondering: is it possible to cast CO[SUB]2[/SUB]? The fact that carbon dioxide has no liquid state at 1 atm makes it a pain, but suppose you made a metal mold with a fitting on it, and injected CO[SUB]2[/SUB] at high pressure. Would that work? We were thinking about casting sculptural shapes for party decorations, not unlike ice sculptures, but cooler.

Because it sublimates rather easily and the only shapes you could cast would be pretty simple shapes, why not purchase a brick of CO[sub]2[/sub] and use a blowtorch and chisel to sculpt it? Once it was sculpted, you could place it in an airtight container and pressurize it with CO[sub]2[/sub], pack the container in ice, and use other simple methods to keep it close to its ideal shape for a few hours.

Theoretically, you could make a mold and inject high pressure CO[sub]2[/sub], but remember what happens when you stick dry ice in an empty two-liter bottle with even a little bit of warm water and seal the cap – your mold would have to be very strong to resist any boil-over and outgassing that would naturally occur.

Well, you could chill the mold down to dry ice temperatures, but we’re getting pretty complicated.

Cooler, indeed. Even cold! In fact, dangerously so – touching a dry ice sculpture could easily leave a painful injury on a person.

I’d hate to think of the liability issues for anyone using these for party decorations! (Have you considered have some bare electrical wires exposed as decorations at your party? If they’re powered up & throwing sparks, that would also be ‘cool’.)

They’re a reason that people giving parties have used only regular water ice sculptures for many years.

Aw, it’s dang chilly stuff admittedly, but nobody’s gonna get freezer burn from casually brushing against it. Now if folks start getting drunk and tripple dog daring each other to stick a tongue or something on it, well, yeah that’s a recipe for disaster.

I’d be a bit concerned about displacing oxygen in an enclosed party room–this decoration is definitely best suited for outdoors affairs. What about locking an object like a statue or picture…or a keg of beer inside a block of dry ice? The sublimation of the dry ice would be part of the performance/unveiling of the object.

Interesting point. Has anyone ever killed someone with dry ice? (Victim + Big Block o’ Dry Ice) + sealed closet = ??