An Electrospun Purple Fabric for Personal Thermal Management

Area of Science:

• Materials Science
• Nanotechnology
• Textile Engineering

Background:

• Passive radiative cooling (PRC) offers personal thermal regulation by reflecting sunlight and radiating heat.
• Developing aesthetically pleasing colored fabrics, especially purple, for PRC is challenging due to the conflict between colorant absorption and cooling principles.
• Purple dyes typically absorb green light, a region of high solar irradiance, hindering efficient radiative cooling.

Purpose of the Study:

• To engineer a purple fabric that achieves efficient passive radiative cooling while maintaining aesthetic appeal.
• To resolve the trade-off between color and cooling performance in wearable fabrics.
• To demonstrate a novel application of metal-organic frameworks (MOFs) in colored PRC textiles.

Main Methods:

• A one-step electrospinning strategy was employed using thermoplastic polyurethane.
• Metal-organic frameworks (MOFs) were utilized as spectrally selective colorants, incorporating imidazole and Co-N frameworks for mid-infrared emission.
• Zinc oxide (ZnO) nanoparticles were integrated to enhance synergistic scattering for solar reflectance.

Main Results:

• The engineered purple fabric achieved a mid-infrared emissivity of 96.4% due to MOF's vibrational absorption.
• The fabric demonstrated an average solar reflectance of 87.6%, with specific high reflectance in visible (90.1%) and near-infrared (90.7%) ranges.
• Outdoor tests showed the fabric was 4.2°C and 6.2°C cooler than commercial white and purple cotton fabrics, respectively.

Conclusions:

• A novel purple cooling fabric was successfully engineered using MOFs and electrospinning.
• This approach effectively balances aesthetic requirements with high-performance passive radiative cooling.
• The study advances the development of next-generation wearable fabrics for enhanced thermal comfort and visual appeal.