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.

The 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 as PowerPoint slide