Antifreeze is an additive in water-based liquid to lower down the freezing point of such liquid. It is used to make use of the colligative properties of solutions specifically freezing-point depression for cold climate and boiling-point elevation to allow higher coolant temperature.
Carbon dioxide can’t exist in three states; Gas, Liquid & Solid. At normal temperatures and pressures, CO2 is colorless with a slightly pungent odor at high concentrations. If compressed and cooled to proper temperature the gas liquifies. Solid CO2, (dry ice) sublimates back to the natural gaseous state.