Synthesis and characterization of hydrophobic reversible thermochromic MicroPCMs with amino resins shell for thermal energy storage

Hydrophobic reversible thermochromic MicroPCMs with amino resins shell. [Display omitted] •The effect of TDI modification on performance of TC-MPCMs was discussed in detail.•HTC-MPCMs possess hydrophobic surface (WCA = 148.5°).•HTC-MPCMs possess excellent latent heat storage capability and cyclic durability. The microstructure and composition of shell of reversible thermochromic microcapsulated phase change materials (TC-MPCMs) are crucial for their performance. High reaction activity between isocyanate group of TDI and active hydrogen of hydroxymethyl amino resin is conducive for TC-MPCMs to obtaining hydrophobic performance. Thus, a new type of TC-MPCMs with hydrophobic amino resins shell is developed via surface modifying using the prefabricated MF resin-encapsulated TC-PCMs as template. The experimental results shown the water contact angles (WCA) of the surface of modified microcapsules increased from 0° to 148.5°, suggesting that shell surface turned hydrophobic. The TC-MPCMs with hydrophobicity possessed good thermal properties (△Hm = 100.0 J·g−1, △Hc = 100.2 J·g−1), thermal stability, satisfactory thermal cyclic durability and reversible thermochromic performance. That might be beneficial for broadening its practical application value in the field of latent thermal energy storage.