Acoustic "Re-charging" of Nanofiber Air Filters

Abstract

The long-term performance of electrostatic fibrous filters is inherently limited by the irreversible dissipation of their embedded charges. Existing regeneration strategies often rely on mechanical contact, which can lead to material degradation. Herein, we present a non-contact acoustic strategy that effectively rejuvenates the electrostatic charge and filtration performance of nanofiber filters. Using membranes fabricated from a poly(vinylidene fluoride) (PVDF)-polysulfone (PSU) blend, we demonstrate that acoustic stimulation (100 Hz, 110 dB, 10 min) serves a dual function: it restores the piezoelectric and triboelectric charges within the nanofibers, while simultaneously facilitating dust removal via fiber vibration. Following charge removal, the initial filtration efficiency for PM0.3 was only 75.14% (solid) and 73.70% (oil), with a pressure drop of 96 Pa. After acoustic treatment, efficiency was dramatically enhanced to 99.99% and 92.90%, respectively, while the pressure drop was reduced to 45 Pa. This work establishes a novel paradigm for developing energy-efficient, high-performance, and durable air filtration systems.