Development of Novel Granular Form Stable Phase Change Material PCM for Orthopedic and Food Delivery Applications

Abstract

The thesis discusses the preparation of exfoliated graphite from commercially available intercalated graphite. The process of exfoliating the intercalated graphite has been holistically characterized using XRD, FTIR, and SEM. The graphite with a surface area of 47.37 cc g-1 with a purity of 99 % was found to have maximum absorption of 80 % (w/w) stearic acid as PCM. In addition, this paper investigates two synthetic routes to prepare the shape-stabilized PCM. Composite 1 refers to stearic acid absorbed in the exfoliated graphite. Composite 2 refers to the stearic acid absorbed in exfoliated graphite which is further treated with an elastomer Styrene ethylene butadiene styrene (SEBS). The leak test performed on both the blends signifies that SEBS is an essential ingredient. The PCM composition optimized in this study can unlock various thermal applications with critical requirements where direct exposure of chemicals to the user is unacceptable. Further, the study itself is envisaged to serve as a framework to develop enhanced shape-stabilized PCMs with tuneable thermal conductivity and extended operation life in application areas where solid-liquid phase transition is undesirable. newlineFurther, the PCM granules obtained were tested for the efficacy in storing and releasing the energy by integrating in two applications Lunch box and orthopedic pads. To construct PCM integrated lunch box, theoretical and experimental studies were conducted. Since harmful chemicals render food unfit for consumption when they come in contact with it, the choice of phase change material is essential. Nevertheless, utilizing the electric lunchbox at work is a bother. Therefore, this part of thesis discusses a prototype of a lunchbox that has been created and can keep food warm after it has been packed at home for 4-5 hours. The thermal resistance of the insulating materials and quantity of PCM are the two design considerations for the lunchbox are covered. To explore this, a warm food criterion at a temperature of 45 °C was used. The con