Synthesis and characterization of micro/nano capsules of PMMA/capric–stearic acid eutectic mixture for low temperature-thermal energy storage in buildings

•The encapsulated PCM was consisted of spherical capsules with mean diameter of 1.3 μm.•Its melting temperature is suitable for free cooling of buildings depending on climatic conditions.•Its LHS capacity is enough to integrate with conventional building materials.•It can be used to fabricate new building elements such as panels, plasterboards, and wallboards.

In this work, polymethylmethacrylate(PMMA)/capric–stearic eutectic mixture (C-SEM) micro/nano capsules were synthesized effectively using emulsion polymerization method. POM and SEM analysis results showed that the synthesized PMMA/C-SEM micro/nano capsules were consisted with spherical shape with uniform structure. The PSD analysis indicated that the mean diameter of the capsules was 1.3 μm and 28.1%-part of the capsules can be characterized as nano-sized spheres. DSC analysis exposed that the synthesized PMMA/C-SEM (1:2) micro/nano capsules has a melting temperature of 21.37 °C, which can be suitable for free cooling of buildings depending on the climatic conditions. It has a latent heat of melting of 116.25 J/g, which can be enough to integrate with conventional building materials. TGA results exhibited that the thermal degradation temperature of the micro/nano capsules is very much higher its melting temperature. Moreover, the synthesized PMMA/C-SEM micro/nano capsules have good thermal reliability, chemical stability and thermal conductivity. By taking into consideration all results, it can be also concluded that the micro/nano encapsulated C-SEM can be used to fabricate new building components.

Graphical abstractThe POM and SEM analysis results showed that the synthesized PMMA/C-SEM micro/nano capsules had spherical shape with compact surface. The particle size distribution (PSD) analysis indicated that the mean diameter of the capsules was 1.3 μm and 28.1%-part of the capsules can be characterized as nano-sized spheres. The DSC analysis exposed that the synthesized PMMA/C-SEM (1:2) micro/nano capsules has a melting temperature and latent heat 21.37 °C and 116.25 J/g, respectively. TGA results exhibited that the thermal degradation temperature limit of the synthesized micro/nano capsules is very much higher its melting temperature. Moreover, the micro/nano encapsulated PCM has good thermal reliability, chemical stability and good thermal conductivity. By taking into consideration all results, it can be also concluded that the PMMA/C-SEM (1:2) micro/nano capsules can be incorporated with building components to fabricate low temperature-energy storing wallboards or panels to decrease indoor temperature swing in buildings.Figure optionsDownload full-size imageDownload as PowerPoint slide