# Thermo-Regulated Cotton: Enhanced Insulation through PVA Nanofiber-Coated PCM Microcapsules
## 4 Discussion  
Investments in thermal insulation not only yield economic benefits by lowering energy costs but also offer substantial environmental advantages. For instance, buildings with enhanced insulation require less energy for temperature regulation, thereby reducing CO\({}_{2}\) emissions [24]. Furthermore, sustainable insulation materials often have superior lifecycle properties, contributing to long-term environmental sustainability. These materials are designed to meet rigorous energy efficiency standards while also being safe and environmentally friendly. The broad size distribution of microcapsules may influence the thermal properties and application performance of the microcapsules. Smaller microcapsules provide a larger surface area-to-volume ratio, which can enhance heat exchange rates. The SEM analysis provided valuable insights into the microstructural characteristics of the cotton fabric treated with coco oil as a phase change material (PCM). The observed spherical formations on the cotton fibers are indicative of successful encapsulation of the coco oil. These spheres are likely the result of the coco oil being encapsulated within the fibers, forming microcapsules that can effectively manage thermal energy through phase transitions. The thermal cycling test, consisting of five heating and cooling cycles, is crucial in demonstrating the stability and functionality of the encapsulated coco oil. Phase change materials like coco oil absorb heat as they melt from a solid to a liquid state and release heat when they solidify. The retention of spherical shapes after multiple thermal cycles suggests that the encapsulation process was effective in preventing oil leakage. If the coco oil were not properly encapsulated, it would likely seep out during the melting phase, leading to irregular shapes or loss of material, which would be detectable in the SEM images. Moreover, the consistency in maintaining the round shapes of the microcapsules throughout the thermal cycles highlights the robustness of the encapsulation. This is essential for the practical application of PCMs in thermal insulation, as it ensures long-term reliability and efficiency. The encapsulated coco oil can repeatedly absorb and release thermal energy without degradation, which enhances the thermal regulation properties of the fabric. Additionally, the encapsulation of coco oil within the cotton fabric offers several advantages. It integrates the PCM directly into the fabric structure, providing a lightweight and flexible thermal management solution. This can be particularly beneficial in applications where traditional insulation materials are not suitable due to weight or rigidity constraints. The FTIR spectra reveal distinct chemical modifications in the cotton fabric post encapsulation with microcapsules containing coco oil and ethylcellulose. Specific absorption bands corresponding to functional groups in coco oil and ethylcellulose confirm their presence on the fabric's surface. For instance, the characteristic peaks of coco oil, such as those associated with the C-H stretching vibrations of aliphatic chains, and the C=O stretching vibrations of esters, are evident in the FTIR spectra. Similarly, ethylcellulose is identifiable through its characteristic ether (C-O-C) and hydroxyl (O-H) stretching vibrations. Figure 8: Thermal behavior for cotton fabric with coco microcapsules and nanofibers during the heating and cooling process for one, five, and fifty cycles. These spectral signatures substantiate the hypothesis that coco oil and ethylcellulose have been successfully integrated into the cotton fabric, forming microcapsules. The presence of these compounds on the fabric's surface strongly indicates that the microencapsulation process was effective. Microencapsulation is crucial as it ensures the stability and functionality of the phase change material (PCM), in this case, coco oil, by preventing leakage and maintaining structural integrity during thermal cycling.