Does fabric help Prevent an ice cube from melting?
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Similar to your question of a few minutes ago, where you asked the same about cotton.
What you have is something colder than its surroundings (ice), which heat from those surroundings will therefore tend to flow into, and warm it up. What you are trying to do is slow that heat flow as much as possible; you can't stop it altogether. So what you need is the best insulator you can find. Insulation is the opposite of conduction. And heat conduction is what you're trying to minimize.
The best common material for accomplishing this is styrofoam. Its insulating property stems from the fact that air is a really good heat insulator; but it carries heat around with it when it flows (convection). So how do you stop it from flowing around? You lock it up in zillions of tiny little rigid bubbles, whose walls are themselves made of a material that's a pretty good insulator, polystyrene plastic -- that's what styrofoam does.
Cotton wadding and fabric are pretty good insulators, too, because they have a microstructure (fibers) that impedes the flow of air. That's how a heavy winter coat keeps you warm in the cold. But as one of the answers to your cotton question pointed out, a little melt water will mostly defeat any insulating effect of these fibrous materials. (If you're soaking wet under that coat, it won't do you a whole lot of good!)
The styrofoam isn't vulnerable to this problem, because its bubbles are closed, and water can't get into/through them. So you can see that you'll want that styrofoam to be a single block, so that there are no channels for melt water to seep through.
The next thing, better than styrofoam, is a thermos flask/bottle. This is a consumer-market version of what physicists call a Dewar flask. It's a double-walled jar, usually glass, with vacuum between the inner and outer layers. Because vacuum is an even better insulator than air -- it doesn't conduct heat at all. Zero. Because vacuum is the complete absence of material of any kind, and it takes matter to conduct heat. So the only path for heat to get in (or out) is through those thin glass walls. And glass is a good insulator, too.
Good luck to you and your ice cube!
What you have is something colder than its surroundings (ice), which heat from those surroundings will therefore tend to flow into, and warm it up. What you are trying to do is slow that heat flow as much as possible; you can't stop it altogether. So what you need is the best insulator you can find. Insulation is the opposite of conduction. And heat conduction is what you're trying to minimize.
The best common material for accomplishing this is styrofoam. Its insulating property stems from the fact that air is a really good heat insulator; but it carries heat around with it when it flows (convection). So how do you stop it from flowing around? You lock it up in zillions of tiny little rigid bubbles, whose walls are themselves made of a material that's a pretty good insulator, polystyrene plastic -- that's what styrofoam does.
Cotton wadding and fabric are pretty good insulators, too, because they have a microstructure (fibers) that impedes the flow of air. That's how a heavy winter coat keeps you warm in the cold. But as one of the answers to your cotton question pointed out, a little melt water will mostly defeat any insulating effect of these fibrous materials. (If you're soaking wet under that coat, it won't do you a whole lot of good!)
The styrofoam isn't vulnerable to this problem, because its bubbles are closed, and water can't get into/through them. So you can see that you'll want that styrofoam to be a single block, so that there are no channels for melt water to seep through.
The next thing, better than styrofoam, is a thermos flask/bottle. This is a consumer-market version of what physicists call a Dewar flask. It's a double-walled jar, usually glass, with vacuum between the inner and outer layers. Because vacuum is an even better insulator than air -- it doesn't conduct heat at all. Zero. Because vacuum is the complete absence of material of any kind, and it takes matter to conduct heat. So the only path for heat to get in (or out) is through those thin glass walls. And glass is a good insulator, too.
Good luck to you and your ice cube!
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Yes, insulation (fabric) will slow the rate at which heat reaches the ice thus slowing how quickly it melts.