Engineering self-assembled 2D nano-network membranes through hierarchical phase separation for efficient air...

Area of Science:

• Materials Science
• Nanotechnology
• Environmental Engineering

Background:

• Existing air filtration materials face challenges with limited structural diversity and a trade-off between particle rejection and air permeability.
• Addressing global air pollution requires advanced filtration solutions with improved performance and efficiency.

Purpose of the Study:

• To design and fabricate a novel biomimetic composite membrane inspired by spider webs for enhanced air filtration.
• To overcome the limitations of conventional air filters by improving particle capture efficiency and air permeability.

Main Methods:

• A hierarchical phase separation strategy was employed to create a composite membrane with a continuous monolayer of 2D nano-networks on an electrospun nanofiber scaffold.
• The membrane structure features hierarchical multiscale architectures, including 2D ultrafine networks of nanowires (31 nm diameter) self-assembled from nanoparticles.

Main Results:

• The biomimetic membrane demonstrated a high PM0.3 capture efficiency of 99.6% with a low pressure drop of 58.8 Pa.
• The membrane exhibits a small average aperture, extremely low network thickness, high porosity, good pore channel connectivity, and abundant polar functional groups.
• Outstanding long-term PM2.5 recycling filtration performance was observed.

Conclusions:

• The spider web-inspired composite membrane offers superior air filtration performance, effectively balancing high particle capture efficiency with low air resistance.
• The hierarchical phase separation strategy provides a feasible and tunable method for constructing 2D nano-networks, showing potential for broad applications in air filtration.