DESC:COMPOSITION FOR THERMAL STORAGE AND HEAT TRANSFER APPLICATIONS ,CLAIMS:1. A method for preparation of a composition, the method comprising the steps of:
a) contacting at least one nanoparticle with at least one alkali metal salt and a metal salt having water of crystallization to obtain a mixture;
b) subjecting the mixture to a temperature in the range of 100 to 200°C in a closed system to obtain dispersed nanoparticles in a mixture of salts; and
c) removing water from the dispersed nanoparticles in a mixture of salts to obtain the composition.
2. The method as claimed in claim 1, wherein the at least one nanoparticle is selected from the group consisting of molybdenum disulfide, cupric oxide, carbon nanotube, functionalized carbon nanotube, multi-walled carbon nanotube, activated carbon, activated carbon sphere, graphene, and combinations thereof.
3. The method as claimed in claim 1, wherein the at least one nanoparticle weight percentage in the composition is in the range of 0.01 to 2 %.
4. The method as claimed in claim 1, wherein the at least one nanoparticle has a particle size in the range of 30 to 500 nm.
5. The method as claimed in claim 1, wherein the at least one alkali metal salt is selected from the group consisting of sodium metal salt, lithium metal salt, potassium metal salt, and combinations thereof wherein, the at least one alkali metal salt is inorganic anions.
6. The method as claimed in claim 1, wherein the at least one alkali metal salt weight percentage in the composition is in the range of 5 to 90 %.
7. The method as claimed in claim 1, wherein the at least one alkali metal salt is a combination of lithium and potassium nitrate wherein potassium nitrate weight percentage in the composition is in the range of 60 to 70 % and lithium nitrate weight percentage in the composition is in the range of 5 to 20 %.
8. The method as claimed in claim 1, wherein the metal salt having water of crystallization is selected from the group consisting of alkali metal salt, alkaline earth metal salt, and transition metal salt.
9. The method as claimed in claim 1, wherein the metal salt having water of crystallization has melting point in the range 40 to 120 °C.
10. The method as claimed in claim 1, wherein the metal salt weight percentage in the composition is in the range of 10 to 35 %.
11. The method as claimed in claim 1, wherein the metal salt is hydrated calcium nitrate.
12. The method as claimed in claim 1, wherein the composition has moisture content in the range 3 to 13 %, and has a melting temperature in the range of 100 to 150 °C.
13. The method as claimed in claim 1, wherein the mixture of salts containing dispersed nanoparticles is subjected to a temperature of 100 to 200 °C for 0.5 to 2 hours.
14. A composition comprising of (a) at least one nanoparticle (b) at least one alkali metal salt; and (c) a metal salt having water of crystallization, wherein the composition has a melting temperature in the range of 100 to 150 °C.
15. The composition as claimed in claim 14, wherein the at least one nanoparticle is selected from the group consisting of molybdenum disulfide, cupric oxide, carbon nanotube, functionalized carbon nanotube, multi-walled carbon nanotube, activated carbon, activated carbon sphere, and graphene.
16. The composition as claimed in claim 14, wherein the at least one nanoparticle weight percentage in the composition is in the range of 0.01 to 2 %.
17. The composition as claimed in claim 14, wherein the at least one nanoparticle has a particle size in the range of 30 to 500 nm.
18. The composition as claimed in claim 14, wherein the at least one alkali metal salt is a combination of lithium and potassium nitrate wherein potassium nitrate weight percentage in the composition is in the range of 60 to 70 % and lithium nitrate weight percentage in the composition is in the range of 5 to 20 %.
19. The composition as claimed in claim 14, wherein the metal salt weight percentage in the composition is in the range of 10 to 35 %.
20. The composition as claimed in claim 14, wherein the metal salt is hydrated calcium nitrate.
21. The composition as claimed in claim 14, for use in solar thermal energy storage.