EFFECT OF STATIC ELECTRIC FIELD ON SOLIDIFICATION PROCESS OF ORGANIC PHASE CHANGE MATERIAL (PCM) FATTY ACID LAURIC ACID (C12H24O2) AND STEARIC ACID (C18H36O2)

• Main Author: Yusuf, Akhmad
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/52623
• Institution: Institut Teknologi Bandung

Latent heat released during the freezing process of organic phase change materials (PCM), which occurs at a constant temperature, can be modified using an electric field, through a process called electrofreezing. To date, studies of the effects of electric fields on freezing have only been in saline or hydrated saline materials from inorganic PCM, and the effect is a decrease in the degree of supercooling, an increase in the nucleation rate, and a reduction in induction time due to changes in Gibbs free energy. In this study, research was carried out on the electrofreezing of stearic acid and lauric acid which are the fatty acid groups of organic PCM. Organic PCM generally has relatively small or even zero supercooling, the effect of the DC electric field is more pronounced at the time of latent heat dissipation at constant temperature and crystallization time. Comparisons were also performed with inorganic PCM on CaCl2.6H2O samples using previously published data. In his analysis, the two-time parameters are closely related to the electrical and thermal conductivity of the sample. The existence of different nucleation mechanisms for fatty acids and CaCl2.6H2O is related to the interaction between the crystal sample and the electric field, as well as the different joule heating effects. Changes in chemical structure and thermal stability due to electric field treatment were evaluated by measuring the Fourier transform infrared spectra, decomposition, melting temperatures, and calculating the latent heat of fusion. This research also discusses the potential application of lauric acid and stearic acid as PCM composites in thermoresponsive devices for the efficiency of electricity to heat conversion.