Developing functional textiles with thermal insulation and hydrophobic properties is of significant interest. This study successfully synthesizes K2Ti6O13 (potassium titanate, KTO) whiskers via the hydrothermal method and prepares KTO composite silica polyester fabric (KSP) through impregnation technology, exhibiting excellent thermal insulation and hydrophobic qualities. X-ray diffraction (XRD) analysis verifies the high purity and excellent crystallinity of KTO whiskers and SiO2 micro-powder. Scanning electron microscopy (SEM) images reveal that the KTO whiskers retain their original morphology and exhibit uniform size distribution, with an average length of around 1 μm and an aspect ratio of 40. Transmission electron microscopy (TEM) images further validate the planar growth properties of the whiskers. Raman spectroscopy research elucidates the vibrational modes of various chemical bonds in the KTO whiskers. The ultraviolet–visible–near-infrared spectrophotometer test results demonstrate that the KSP fabric reflects 43.5 % more light than standard polyester fabric and substantially lowers the temperature in the covered chamber under simulated sunlight exposure, achieving a maximum reduction of 7.4 °C. The KSP fabric has exceptional hydrophobic properties, completing a contact angle of 153.2° and maintaining reflectance stability, with a mere 5.92 % reduction after 20 days of outside exposure. This work offers substantial reference value for the advancement of practical textiles.

Phase change materials are applied in heat storage systems because of their high latent heat. The low thermal conductivity of phase change materials limits the heat transfer rate. Rectangular grille fins, semicircular wave fins, cosine wave fins, and triangular wave fins are designed to enhance the heat transfer rate in flat-plate storage modules. The addition of Al2O3, CuO, and Fe3O4 at 1 %, 3 %, 5 %, and 7 % volume fractions is investigated based on the triangular wave fins to improve the heat storage performance. Compared with the finless structure, the complete melting time of phase change materials is reduced by 4.70 %, 7.10 %, 9.15 %, and 10.71 % in rectangular grille fins, semicircular wave fins, cosine wave fins, and triangular wave fins modules. The heat storage power of a triangular fin module increases by 7.88 % relative to the finless module. The melting time is shortened for all nanoparticles as the volume fraction increases, accompanied by an increase in the average temperature. The melting rate of phase change materials is improved by 16.84 % with the addition of 7 % Al2O3 nanoparticles and triangular wave fins relative to the bare cavity. Compared with pure phase change materials, the heat storage power is improved by 11.11 % owing to the synergistic effect of triangular wave fins and Al2O3 nanoparticles. Enhancement strategies for latent heat storage systems are provided through the synergistic combination of periodic fins and nanoparticles.