Improvement of Aerosol Filtering Performance of PLLA/PAN Composite Fiber with Gradient Structure

Area of Science:

• Materials Science
• Nanotechnology
• Environmental Engineering

Background:

• Commercial air filters struggle with efficiency and moisture in humid conditions.
• Condensed aerosol particles exacerbate performance issues in current air filtration materials.

Purpose of the Study:

• To design and prepare a PLLA/PAN composite fiber material with a gradient structure for improved air filtration.
• To address the limitations of existing non-woven air filtering materials in high-humidity environments.

Main Methods:

• Electrode sputtering electrospinning technology was employed to create the composite fiber material.
• Characterization included SEM, XRD, FTIR, wettability, mechanical testing, and BET surface area analysis.
• Filtration efficiency was tested using NaCl aerosol particles.

Main Results:

• Optimized fiber diameters (PAN: 140-300 nm, PLLA: 700-850 nm) resulted in dense, uniform fiber meshes.
• The PLLA/PAN composite exhibited combined hydrophobicity and hydrophilicity with stable electrostatic effects.
• Achieved 99.98% filtration efficiency for 0.3 μm NaCl aerosol particles with a quality factor of 0.0968 Pa⁻¹.

Conclusions:

• The PLLA/PAN composite fiber material offers a new approach for high-performance air filtration.
• This method enables large-scale production of stable, low-cost polylactic acid nanofiber composites.
• The material effectively filters multiphase flow, preventing air resistance increase in humid conditions.