<i>In Situ</i> Active Poling of Nanofiber Networks for Gigantically Enhanced Particulate Filtration

Enhancing the filtration efficiency of air filtering material without increasing its airflow resistance is a major challenge and of great significance. In this work, we report a type of active-poled nanofiber onto which in situ active poling is applied. It results in significantly enhanced filtration efficiency as well as dust holding capacity while keeping the airflow resistance constant. Owing to the in situ applied electric field, the nanofibers as well as the particulates are polarized. As a result, at a poling voltage of 2 kV, the removal efficiency and the quality factor for PM2.5 are enhanced by 17% and 130%, respectively. More importantly, the dust holding capacity represents a 3.5-fold enhancement over normal nanofibers. The approach reported in this work has the potential of being practically utilized in air purification purposes because it can bring about not only promoted filtration performance but also lowered noise and reduced power consumption.