# Thermo-Regulated Cotton: Enhanced Insulation through PVA Nanofiber-Coated PCM Microcapsules
## 1 Introduction
However, the space requirements for mineral wool insulation can be a limitation, especially in designs where compactness and space utilization are crucial. Mineral wool insulation typically requires a substantial thickness to achieve desired thermal resistance, which can be problematic in buildings where space is at a premium. This limitation necessitates a closer look at alternative solutions that are not only thinner but also more sustainable. Alternative insulation materials, such as sheep wool, have been gaining attention in recent years. Sheep wool insulation, for instance, offers comparable thermal insulation characteristics to mineral wool and, in some cases, even outperforms it in specific applications. Importantly, sheep wool is more ecological, featuring fewer health risks and a lower environmental impact than traditional mineral wool. Studies have shown that sheep wool insulation has comparable building physics and acoustic properties to mineral wool, making it a suitable alternative in terms of performance while being more environmentally friendly and sustainable [12]. Additionally, the development of innovative mineral fiber insulating panels with lower thicknesses and enhanced sustainability, acoustic insulation, and fire resistance characteristics have been investigated, showing promise for building refurbishment, especially in historical buildings [13]. These advancements suggest a shift towards more compact and sustainable insulation solutions, offering viable alternatives to traditional mineral wool. Cotton, as an alternative insulation material for buildings, hasbeen explored in various studies. A novel environmentally friendly thermal insulation material has been developed using binderless cotton stalk fiberboard (BCSF). This material is made from cotton stalk fibers without any chemical additives, employing high-frequency hot-pressing. The results indicated that BCSF with densities ranging from 150-450 kg/m\({}^{3}\) has thermal conductivity values close to those of expanded perlite and vermiculite in the same density range, making it suitable for ceiling and wall applications to save energy [14]. One study investigated the functionalization of cotton fabric using hollow glass microspheres and titanium dioxide (TiO\({}_{2}\)) nanoparticles, focusing on various properties including thermal insulation. The presence of these microspheres on the surface of cotton improved the thermal resistance by 78%, demonstrating superior thermal insulation. This suggests that similar nanomaterials, when applied to cotton fabrics, could enhance their thermal insulation properties [15]. Another study developed reactive multiwall carbon nanotube (MWCNT) nanofluid-coated cotton fabrics, which showed improved thermal conductivity while preserving electrical insulation. This research demonstrates the potential of nanomaterial coatings in enhancing the thermal properties of cotton fabrics [16]. Additionally, a study on electrospun nanofibers deposited on clothing textiles, including cotton, showed that nanofiber layers significantly influence the thermal and physiological properties of the fabric, which could be relevant for thermal insulation applications [17]. These studies highlight the potential of nanofibers and nanomaterials in enhancing the thermal insulation properties of cotton fabrics, although direct studies on nanofiber layers on cotton fabrics specifically for thermal insulation are limited. This paper aims to explore the potential of these materials in developing advanced thermal regulation textiles. The study delves into the synthesis and characterization of microcapsules with a coconut oil core and ethylcellulose shell, their integration into cotton fabrics, and how a protective layer of PVA nanofibers influences the thermal behavior. The implications of these developments for the enhancement of thermal insulation in functionalized textiles will be analyzed.