Breathable Window Screen Against High-velocity Droplet Penetration.

Area of Science:

• Materials Science
• Fluid Dynamics
• Surface Chemistry

Background:

• Window screens allow ventilation but permit water infiltration, especially during heavy rainfall.
• Existing screens lack effective defense against high-velocity water droplets, leading to indoor flooding.

Purpose of the Study:

• To develop and evaluate a novel bilayer mesh with synergistic wettability for superior droplet penetration resistance.
• To address the limitations of conventional window screens in preventing water ingress.

Main Methods:

• Fabrication of a bilayer mesh with a superhydrophilic (SHPi) upper surface and a Janus wettability bottom surface.
• Testing the mesh's resistance to high-speed water droplet impact at velocities up to 4.5 m/s.
• Quantifying droplet penetration ratio under sustained high-velocity impact.

Main Results:

• The SHPi-Janus bilayer mesh demonstrated exceptional resistance to high-speed droplet penetration.
• A droplet penetration ratio of only 3.6% was recorded for the novel mesh under impact.
• This represents a significant improvement over the 61.1% penetration ratio of commercial screens.

Conclusions:

• The SHPi-Janus bilayer synergistic mesh effectively prevents water droplet infiltration, even at high velocities.
• This technology offers a dual waterproof mechanism for both instantaneous and long-term resistance.
• The developed mesh significantly enhances protection against rainfall compared to conventional window screens.