Nano-encapsulated PCMs

The paraffins are usually used as core material encapsulated in a shell polymer. This systan can be prepared in different sizes, macro, micro, and nano-encapsulated PCM [17]. 

Nanofluids or PCM slurries prepared from carrier fluids mixed with nanocapsules showed a significant increase in the capacity of heat transport values. In addition, nanocomposites made by nanomaterials with high thermal conductivity such as alumina and cupper nanoparticles, carbon nano-fibers, or and graphite nanoplatelets dispersed into paraffin can be used to enhance heat transfer and thermal properties [20]. Molecular dynamics simulations were performed by Rao et al. [20] to investigate the heat and mass transfer mechanism of nanoparticle-enhanced PCM and nano-encapsulated PCM. The nano-encapsulated PCM was studied using n-octadecane as core and SiO as shell material. Nanoparticle-enhanced PCM was studied by addition of Al nanoparticles with four different... 

PCMs such as n-nanodecane, n-eicosane, n-heneicosane, and n-docosane. The results of this study showed that the thickness of the shell material had a great influence on the self-diffusion coefficient, radial distribution function, end-to-end distance, and bond torsion angles distribution of the nano-encapsulated PCM. The authors also noted that the thicker the shell is, the more restricted are the torsion and the extension of the core material molecule chains, especially those that are close to the shell. The mass diffusion and the storage of thermal energy are enhanced when the thickness of the shell decreased, but the capsule is prone to break if the shell is too thin. In the nano-encapsulated PCM design, the influence of the shell thickness must be taken in account [20,21]. 

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