FAST FREEZING HYDRATED SALT BASED PHASE CHANGE MATERIAL (PCM)

A fast-freezing hydrated salt-based phase change material (PCM), is disclosed herein. The hydrated salt PCM has a faster freezing time, low super cooling and minimal phase differences with repeated cycles. The viscosity of the PCM is increased using polyacrylamide hydrogels in order to thereby avoid phase differences and decrease the freezing time. The salt solution is prepared with the help of nucleating agents (such as, borax decahydrate) by preventing the supercooling 3% of the salt solution and is dissolved in hot water. Subsequently, 4% of sodium fluoride and 3% of sodium chloride are added to the water and stirred still the solution is dissolved. The thermal conductivity of the salt solution was increased by the addition of 1% of graphite flakes of mesh size 200 800 microns and was thoroughly mixed in the salt solution. 2.5% (w/v) of the grinded and dried hydrogel was added to the salt solution at a temperature of 50oC and thoroughly mixed for 4 hours in order to increase the viscosity and make the graphite flakes evenly dispersed in the salt solution.