Opportunity
The increasing demand for energy-efficient cooling technologies has highlighted the limitations of conventional methods, such as air conditioning, which consume significant energy and contribute to environmental degradation. Radiative cooling, which leverages the natural emission of thermal radiation to outer space without energy input, presents a promising alternative. However, existing radiative cooling textiles face critical challenges, particularly in managing moisture transport. Current fabrics often exhibit bidirectional moisture transfer, meaning they absorb and release moisture in both directions (skin-to-environment and vice versa). This limits their effectiveness in high-humidity conditions and reduces wearer comfort. Additionally, many radiative cooling materials suffer from complex manufacturing processes and inadequate moisture-wicking properties, hindering their practical adoption in functional apparel, sportswear, and industrial workwear. Addressing these issues requires a material that combines efficient radiative cooling with unidirectional, rapid moisture transport to enhance thermal comfort in extreme environments.
Technology
The patent introduces an innovative double-layer film composed of a hydrophilic layer (containing titanium carbide and polyurethane) and a hydrophobic layer (containing polyvinylidene fluoride and adhesive). The key innovation lies in the material’s hierarchical structure and chemical treatment. The hydrophilic layer accelerates moisture diffusion, while the hydrophobic layer prevents reverse permeation, ensuring one-way moisture transport. Alkaline treatment (e.g., sodium hydroxide) further enhances hydrophilicity by introducing functional groups that improve water molecule transport. The film is fabricated using electrostatic spinning, which allows precise control over layer thickness (0.01–0.015 mm) and porosity. This method ensures high infrared emissivity (8–13 μm wavelength range) for effective radiative cooling, while the material’s lightweight and flexible properties make it suitable for wearable applications.
Advantages
- Superior Cooling Performance: Achieves a temperature reduction of >2°C through high mid-infrared emissivity.
- Rapid Moisture Transport: Moisture permeability exceeds 12,000 g·m²/24h, ensuring quick drying.
- Unidirectional Moisture Management: Hydrophobic/hydrophilic bilayer design prevents reverse moisture absorption.
- Energy-Free Operation: Utilizes passive radiative cooling, eliminating the need for external power.
- Durability: Functional materials (e.g., titanium carbide) are firmly bonded to the polymer matrix, preventing detachment.
- Scalable Production: Electrostatic spinning and alkaline treatment are simple, low-cost processes.
Applications
- Cooling Apparel: Sportswear, military uniforms, and industrial workwear for extreme heat conditions.
- Building Materials: Energy-saving films for windows or roofs to reduce indoor cooling loads.
- Smart Textiles: Integration into wearable devices for thermal regulation.
- Medical Textiles: Breathable wound dressings or cooling garments for patients.
