Air pollution poses a global challenge with serious impacts on both public health and the environment. Prolonged exposure to particulate matter (PM) has been associated with respiratory illnesses. While mechanical filtration technologies are commonly used to capture airborne particles, their effectiveness for fine particles is limited by the larger fiber diameters (>1 µm) and pore sizes produced through conventional manufacturing techniques. To achieve standard filtration rates, these filters often rely on using thicker material layers.

This study explored the fabrication of lightweight electrospun polymethylmethacrylate (PMMA) nanofibers through electrospinning for enhanced particle capture. A cationic surfactant was added as a dopant to improve fiber morphology. Polymer concentrations were adjusted to produce nanofibers with varying mean diameters, which were analyzed using scanning electron microscopy (SEM). The influence of fiber diameter (d_f), filter area weight (A_w), and face velocity (v) on filtration performance against NaCl aerosols was evaluated using a home-made setup in accordance with ANSI/ASHRAE Standard 52.2-2017, alongside simulations based on air filtration theory.

The electrospinning process successfully produced PMMA nanofibers with diameters below 1 µm, ranging from 137 nm to 957 nm. A sample filter (d_f = 192 nm, A_w = 1.2 g/m²) demonstrated filtration efficiencies exceeding 95% for particles sized between 0.3 and 10.0 µm at a pressure drop of 130 Pa (v = 5 cm/s). Simulations highlighted improvements in both direct and diffusive interception as fiber diameter decreased. These findings offer valuable insights into optimizing fiber morphology of polymer nanofibers to improve particle capture for specific sizes.

Yuanzhi ZHENG

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