Photo-cured phase change energy storage material with photo-thermal conversion, self-cleaning and electromagnetic shielding performances via the lamellar structure strengthened by segment rearrangement of dynamic disulfide bond

Abstract

At present, phase change materials (PCMs) with single function hardly meet the needs of advanced intelligent materials in practical applications, and the multifunction integration is the current trend. However, photo-cured multifunctional PCMs are hampered by insufficient transparency due to adding functional fillers, such as carbon and metal materials. The novel strategy is necessary to overcome this limitation. Here, a photo-cured multifunctional PCM is prepared by using the design of a lamellar structure composing the photo-cured phase change polymer layer and the functional fillers layer. The curing of the phase change polymer is realized by the photo-induced "thiol-ene" click reaction, and reversible dynamic disulfide bonds are introduced into the PCM, which not only gives the phase change crosslinked network reprocessability, but also strengthens the interface layer by the chain rearrangement to form a stable composite structure. The carboxylated multiwalled carbon nanotubes (CCNTs) and silver nanowires (AgNWs), as functional fillers, give the PCM photo-thermal conversion, self-cleaning and electromagnetic shielding (EMI SE) performances. Its phase change latent heat and photo-thermal conversion can reach 105.2 J/g and 78.5%, and the water contact angle is 142° with self-cleaning performance. In addition, due to the dense and well-developed conductive path formed by AgNWs layer on the PCM surface, the EMI SE effect can reach 39 dB with only 6.3% (in mass) filler content and 7.2% phase change latent heat loss. As far as we know, this is the first report about photo-cured PCMs with self-cleaning, photo-thermal conversion and EMI SE performances.