# Thermo-Regulated Cotton: Enhanced Insulation through PVA Nanofiber-Coated PCM Microcapsules
## 1 Introduction  
PCMs leverage latent heat that can be stored or released within a narrow temperature range, changing their state with temperature fluctuations. The integration of phase change materials (PCMs) into textiles represents a significant advancement in the development of smart and functional fabrics. PCMs are substances with a high latent heat of fusion, which means they can absorb or release a large amount of energy at a specific temperature. This unique property enables textiles containing PCMs to maintain a stable temperature, reducing the thermal gap experienced by the wearer in varying environmental conditions. When integrated into textiles, these materials provide thermal regulation through energy absorption during heating and energy release during cooling. This capability is particularly valuable in clothing for cold environments, offering improved comfort and energy efficiency [1]. The application of microencapsulation technology in embedding PCMs into textiles has opened new avenues for improving thermal comfort and energy efficiency. Phase change material (PCM) microencapsulation involves enclosing the PCM within a protective shell to form microcapsules. In the context of textiles, these microcapsules can be applied to fabrics for various functional benefits such as preventing the oil from leakage when melting. Microapsules, consisting of a core material where the PCM is contained and a protective shell, offer a method to incorporate PCMs into fabrics without altering their inherent properties [2]. Various organic and inorganic PCMs exist with a range of melting and solidifying temperatures. Techniques like microencapsulation have been developed to integrate PCMs into textiles, enhancing properties like thermal storage and stability. These advancements are crucial in fields like solar engineering, building materials, and technical textiles [3]. Despite the promising applications, challenges such as material selection, optimal integration techniques, and long-term stability remain. Ongoing research focuses on enhancing the efficiency and applicability of PCMs in textiles, aiming to overcome these hurdles for broader usage [4; 5]. Natural compounds such as paraffins and biodegradable polymers are increasingly favored for this purpose due to growing environmental concerns associated with synthetic chemicals [6]. The ecological impact of producing and disposing of PCM-incorporated textiles is not fully understood. This includes concerns about the sustainability of the raw materials and the potential environmental hazards of the microcapsules themselves. In this context, the use of ethylcellulose for the microcapsule shell, coco oil as the core, and PVA nanofibers as a biodegradable polymer covering, presents an eco-friendly and sustainable approach. Ethlycellulose is a versatile polymer known for its excellent film-forming properties and biodegradability, which makes it an environmentally friendly material [7]. Cocnut oil is a natural PCM with a suitable phase change temperature range for textiles [8; 9], and PVA (polyvinyl alcohol) nanofibers offer a unique combination of strength, flexibility, and biodegradability. One of the challenges is the durability of PCM microcapsules within textiles. [PERSON] [10] focuses on the growth of commercial applications of microencapsulation in textiles, emphasizing the need for robust encapsulation processes to ensure the effective imparation of finishes and properties on textiles, which could be compromised during fabric manipulation. Repeated washing, exposure to UV light, and mechanical stress can affect the performance and lifespan of these microcapsules [11]. While significant progress has been made in the development and application of PCM microcapsules in textiles, further research is needed to address the gaps in long-term performance, environmental impact, and the standardization of testing methods. Mineral wool is widely used for building insulation due to its thermal and acoustic properties.