Preparation and application of hydrophobic phase change microcapsules with siloxane/long-chain alkane polyurethane shell

Abstract

In this paper, a preparation method for multifunctional microcapsules integrating hydrophobicity and phase change energy storage is introduced. A low-surface-energy hydrophobic shell with siloxane and long-chain alkane structures was constructed through the interfacial polymerization of hydroxyl-terminated polydimethylsiloxane (OH-PDMS) and glyceryl monostearate (GMS) with isophorone diisocyanate (IPDI). The effects of the shell structure on the surface morphology, chemical structure, thermal stability, phase change performance, and hydrophobic properties of the microencapsulated phase change materials (MEPCMs) were investigated. The results showed that the hydrophobic shell endowed the MEPCMs with excellent compactness, phase change performance, and cycling stability. After continuous treatment at 150 °C for 60 min, the mass loss rate was only 6.07 %, and the thermal storage capability reached as high as 93.78 %. Even after 1000 thermal cycles, the MEPCMs maintained excellent heat storage performance. The fabric treated with MEPCMs coating exhibited superior temperature regulation and hydrophobic properties, with a water contact angle (WCA) of 135.3°, as well as antifouling and self-cleaning capabilities. In addition, test results indicated that the treated fabric retained stable hydrophobic properties even after multiple washing, exposure to high and low temperatures, sunlight, and abrasion, demonstrating good durability and weather resistance.