Smart solar-regulating phase-change thermal storage window

• Main Author: Michael Kerenza Gouw
• Other Authors: Long Yi
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2021
• Subjects: Engineering::Materials
• Online Access: https://hdl.handle.net/10356/148193
• Institution: Nanyang Technological University

Phase change material (PCM) is commonly researched and used as thermal energy storage by utilizing its latent heat. Gelatin is an example of PCM that has good transparency and favorable transition temperature. Hydroxypropyl cellulose (HPC) is a promising thermochromic material which shows attractive solar regulating properties. Combining gelatin’s property as PCM and HPC’s property as thermochromic material can produce a superior material for smart solar-regulating phase-change thermal storage window application. In this study, gelatin gels and gelatin-HPC gels were prepared and investigated in terms of their thermal properties, transparency, and transmission in low and high temperature. The experimental result shows that 10% gelatin gel (G2500) annealed for 1 hour have a latent heat of 3.4 J/g and gelation temperature of 29.9°C. Upon mixing of G2500 with equal parts of HPC, G2500-HPC have a latent heat of 1.6 J/g and gelation temperature of 30.1°C. In addition, G2500-HPC have a Cp of 4.0 J/g°C and thermal conductivity of 0.5 W/mK, which are both higher compared to HPC. G2500-HPC gels were observed to possess HPC’s thermochromic properties with a Tlum of 78.0%, ΔTsol of 50.8%, and LCST of 40°C, showing promising properties for smart window application. Gelatin-HPC gel was found to have gelatin gel’s latent heat storage capabilities and HPC hydrogel’s thermochromic properties. This is the first reported reversible smart composite that gives superior thermochromic property integrated with reasonable gelation temperature and latent heat, which are suitable for energy saving windows. Further study was recommended to investigate the relationship of gelatin/HPC ratio to the transparency of gelatin-HPC gels and the effect of adding more DMSO to the LCST of gelatin-HPC gels.