Opportunity
As global temperatures rise, individuals are increasingly exposed to severe heatwaves in hot, humid, and sunny environments, elevating the risk of heat-related illnesses. Traditional personal cooling methods often rely on energy-intensive air conditioning systems, which contribute significantly to energy consumption and greenhouse gas emissions. Existing passive radiative cooling textiles face several challenges, including insufficient cooling power, high production costs, poor scalability, oxidative degradation, and complex, inefficient manufacturing processes. These limitations hinder their widespread adoption for personal thermal management. There is a pressing need for an energy-free, scalable, and highly efficient cooling textile that can provide effective personal cooling without exacerbating environmental issues.
Technology
This patent discloses an innovative method for manufacturing a radiative cooling textile using electrospinning technology. The process involves creating an organic solution containing a thermoplastic polymer, such as polyethylene (PE), and adding reflective metal oxide nanoparticles, like zinc oxide (ZnO), to form a suspension. This suspension is electrospun onto a substrate, such as aluminum foil, under controlled voltage conditions (e.g., 25 kV) to form a nanofibrous fabric. A subsequent heat-pressing treatment at specific parameters (e.g., 0.14 MPa, 105°C, 30 minutes) enhances inter-fiber bonding and mechanical strength. The resulting fabric features a porous structure with embedded ZnO nanoparticles, which provides high solar reflectivity (91%) and mid-infrared transmissivity (81%). This allows the textile to reflect most incoming solar radiation while efficiently transmitting body heat as mid-infrared radiation to the cooler environment, enabling passive cooling without energy consumption.
Advantages
- Provides passive radiative cooling without electricity consumption.
- Offers high solar reflectivity (91%) and mid-infrared transmissivity (81%).
- Reduces simulated skin temperature by up to 9°C compared to cotton.
- Excellent breathability, water vapor transmission, and fast-drying properties.
- Enhanced mechanical strength and durability after heat-pressing treatment.
- Scalable production using electrospinning technology.
- Contributes to energy savings and reduction in greenhouse gas emissions.
Applications
- Personal cooling garments for outdoor workers, athletes, and military personnel.
- Smart textiles for healthcare and wellness products.
- Building materials for energy-efficient facades and roofs.
- Automotive interiors for enhanced thermal comfort.
- Protective clothing for extreme heat environments.
