# Thermo-Regulated Cotton: Enhanced Insulation through PVA Nanofiber-Coated PCM Microcapsules
## 4 Discussion
The integration of coco oil microcapsules (MC) and a PVA nanofiber veil onto cotton fabric exhibits a significant improvement in thermal management properties. Individually, both the microcapsules and the nanofibers contribute to temperature regulation, but when combined, they produce a synergistic effect that enhances heat retention and overall thermal insulation performance. The coco oil microcapsules are effective in reducing the fabric temperature during cooling due to their phase change properties. As the temperature rises, the coco oil within the microcapsules absorbs heat by melting, thus preventing the fabric from heating up rapidly. Conversely, during cooling, the coco oil solidifies, releasing the stored heat and maintaining a stable temperature for an extended period. This phase change behavior is crucial for creating a thermally regulated environment, which is beneficial for applications requiring consistent temperature control. The PVA nanofiber veil adds another layer of thermal insulation by acting as a protective barrier. The nanofibers provide additional insulation by trapping air within their structure, which reduces thermal conductivity. This effect is similar to that of traditional insulating materials, where the trapped air acts as a thermal barrier. Moreover, the nanofiber veil also plays a protective role by encapsulating the microcapsules, preventing them from being released during fabric manipulation or wear. This ensures that the microcapsules remain intact and functional throughout the lifecycle of the fabric. When the coco oil microcapsules and the PVA nanofiber veil are used together, they create a synergistic effect that significantly enhances the thermal insulation properties of the fabric. The combined system benefits from the phase change properties of the microcapsules and the insulating characteristics of the nanofibers. This dual-layer approach not only improves heat retention but also ensures that the fabric's surface temperature remains manageable, preventing it from becoming excessively hot or cold. The nanofiber veil ensures the structural integrity of the microcapsules, protecting them from mechanical stress and extending their functional lifespan. This synergistic combination is particularly advantageous in applications where thermal regulation is critical, such as in protective clothing, outdoor gear, or thermal blankets. The enhanced heat retention and stability provided by the microcapsules and nanofiber veil can improve comfort and energy efficiency, making the fabric suitable for a wide range of thermal management applications not only for textile goods but for construction, civil engineering, food packages, cargos, etc. [25; 26; 27; 28]. The close match between the first and the fiftieth heating and cooling cycle implies that the ethylcellulose shell created to retain the coco oil inside is hard enough to resist the increase in volume due to the oil expansion when heated. Furthermore, as the fabric's thermal behavior is stable across multiple heating and cooling cycles it evidences the reversibility of the process, as the ethylcellulose shell prevents the oil from leakage when it melts due to the increase in temperature. This could be important for applications where the fabric is subject to thermal cycling, such as isolation materials in buildings. The reversibility of the thermal treatment confirms that the ethylcellulose is part of the shell and the coco oil is kept inside the shell. Furthermore, the SEM study with microcapsules on the surface confirms that the ethylcellulose shell is hard enough to bear the oil pressure when it melts, as the shell is not broken and prevents oil leakage. Thus, this confirms that the little spheres observed by SEM are something more than the solid coco oil.