METHOD

Aim: To prevent the ice from melting
Materials: Aluminium foil, Styrofoam box

In order to melt, a block of ice needs to absorb a considerable amount of energy. The ice and ice water will stay at freezing temperature until the ice has nearly completely melted.

Convection and Conduction

• An ice cooler mainly has to prevent two kinds of warming: convection and conduction. Convection occurs when currents of a fluid such as air move heat from a hotter object to a cooler one. Conduction occurs when heat moves directly from a warmer object to an adjacent colder one. Coolers are designed to minimize both kinds of heating.
  

Preventing Conduction

• Warmer molecules are moving faster than cooler ones. When a warm molecule bumps into a cold one, some of that motion is transferred, making the cold molecule move a little faster (i.e., get a little warmer.) Air is an extremely poor conductor because the molecules are spread out. Styrofoam has lots of tiny air bubbles inside of it. The heat can not flow efficiently through the material from outside to inside, since all of the air bubbles slow it down. Air does leak through, but it does so very slowly, keeping things cool inside.

Preventing Convection

• When a cooler is opened, convection currents immediately take their toll. Warm air blows in, melting the ice inside and warming up the cooler. As long as styrofoam coolers are kept closed most of the time, convection does little to warm them up. Air currents can warm the surface of the cooler, but this warmth takes a long time to get inside because of the insulating properties of the styrofoam.
• ALUMINIUM:
  

Although ice cannot be prevented from melting , there are ways to keep it frozen for just a little longer. Thermally insulated cooler boxes are pretty good for this. These containers prevent the transfer of heat from the inside of the container to the exterior and vice-versa. Ice buckets and Styrofoam boxes take advantage of this principle to keep ice from melting. Common thermal insulators include nylon lined fabrics, styrofoam and hard plastics.

Keeping ice in light-colored containers or reflective containers might also help keep it frozen. Theoretically, lighter colors and reflective surfaces absorb less radiation from the sun. This should mean that a smaller quantity of heat would be and therefore the ice should melt more gradually. As an alternative to reflective containers, perhaps the ice can be covered with aluminum foil to obtain similar results.