Electrostatic Flocking of Hierarchically Micro/Nanostructured Natural Silk Fibers for Efficient Passive Radiative...

Area of Science:

• Materials Science
• Sustainable Energy
• Textile Engineering

Background:

• Passive radiative cooling offers a sustainable solution to reduce global energy consumption with zero energy consumption and zero CO2 emission.
• Natural silk fibers possess unique optical and morphological properties, mimicking structures that provide thermal protection in nature.

Purpose of the Study:

• To demonstrate the facile construction of hair-like arrays of short silk fibers (SSFs) for efficient passive radiative cooling.
• To enhance both reflectance and emittance properties for improved cooling performance.

Main Methods:

• Electroflocking technique used to create SSF arrays on PDMS films and cotton fabric.
• Characterization of optical properties (reflectance and emittance) in the visible and mid-infrared ranges.
• Experimental evaluation of temperature reduction under solar radiation.

Main Results:

• SSF-coated PDMS films reduced substrate temperature by 7.6 °C compared to bare PDMS under solar radiation.
• SSF-coated cotton fabric reduced microenvironment temperature by 5.6 °C compared to pristine cotton.
• The SSF material demonstrated a 3.6 °C greater temperature reduction than pure silk fabric.

Conclusions:

• Electroflocking of SSFs provides a simple, robust, and scalable method for producing highly efficient passive radiative cooling materials.
• This approach offers significant potential for applications in textiles and coatings to mitigate heat stress and reduce energy demand.