FABRICATION AND CHARACTERIZATION OF NANO MATERIALS ENHANCED MICROENCAPSULATED PCM FOR PASSIVE COOLING

Abstract

In past several decades, rising global temperatures have become a phenomenon that mankind faces. In modern society, buildings are one of the biggest contributors for energy consumption accounting for 30% to 40% of global energy consumptions and greenhouse emissions (Waqas & Din, 2013). An estimation of the destructive impact will grow by 1.8% per year through 2050 indicating a worse scenario on future consumption and emissions than today (Akeiber et al., 2015). Therefore, passive cooling techniques through adoption of thermal energy storage (TES) by means of latent heat is a promising alternative to conventional cooling systems in tropical climates like Singapore. In recent years, many studies and attention have been placed on employing phase change material (PCM) as TES systems. While with the development of microencapsulation technique, the existing defects of pure PCM such as leakage issues and thermal properties can be overcome. However, there are still some drawbacks on microencapsulated PCM in terms of thermal conductivity, thermal energy storage capacity and heat resistant property. Therefore, Nano-enhanced Microencapsulated Phase Change Material (NeMPCM) has been introduced as a better alternative. In this study, fabrication of MPCM were synthesized successfully using suspension polymerization method, with n-eicosane of melting point ranging between 34°C – 37°C, and polystyrene (PS) as shell material. The microcapsules were synthesized successfully using suspension polymerization. Different nanomaterials have been researched and studied on, and it is discovered that nano-graphene (Carbon) yielded the most satisfactory result in the enhancement factor of thermal conductivity which was recorded at 7.08 W/(mK) when 6wt% was added. Other good performing nano-enhancers include nano-titanium oxide (Carbon) and nano-silver (Metal).