Hierarchically Patterned Self-Cleaning Polymer Composites for Daytime Radiative Cooling

Area of Science:

• Materials Science
• Nanotechnology
• Sustainable Energy

Background:

• Passive daytime radiative cooling (PDRC) offers a sustainable solution for reducing energy consumption and mitigating global warming.
• Practical application of PDRC is hindered by surface contamination from dust and bacterial accumulation.
• Existing PDRC technologies often lack integrated self-cleaning and antibacterial functionalities.

Purpose of the Study:

• To develop a hierarchically patterned nanoporous composite (HPNC) with integrated self-cleaning and antibacterial properties for enhanced PDRC.
• To investigate the multifunctional capabilities of the HPNC design across different length scales.
• To provide a scalable and low-maintenance solution for practical PDRC applications.

Main Methods:

• Fabrication of HPNC using a facile template-molding method.
• Integration of nanoporous polymer matrix with tunable fillers for cooling.
• Incorporation of microscale pillar array for superhydrophobicity and photocatalytic agents for antibacterial effects.

Main Results:

• Achieved 7.8 °C and 4.4 °C temperature reduction for outdoor personal and building cooling, respectively.
• Demonstrated superhydrophobicity, enabling self-cleaning and antisoiling functions.
• Confirmed photoinduced antibacterial effects from surface photocatalytic agents.

Conclusions:

• The developed HPNC effectively integrates PDRC with self-cleaning and antibacterial functionalities.
• The hierarchical design allows simultaneous optimization of multifunctional properties.
• HPNC presents a promising, scalable solution for practical PDRC with reduced maintenance requirements.