Highly Electrostatic Cellulose Acetate-Based Composite Electret Nanofiber Film for Air Filtration Applications

A highly electrostatic cellulose acetate (CA)-based electret film for air filtration was fabricated by the electrospinning method assisted with the corona charging technique in this work. The highly polar and hydrophobic poly(vinylidene fluoride) (PVDF) was chosen as the electrostatic reinforcement. The results showed that under the dual electric fields, the dipole charges generated from the conversion from a nonpolar α-phase to a polar β-phase of the dipole inside PVDF and the space charge captured at the phase end traps of CA and PVDF give CA/PVDF films high static electricity. Especially, the composite film with 40 wt % PVDF exhibited an ultrahigh surface potential of 2.146 kV and excellent filtration efficiency of 97.27% for PM 0.3 with a pressure drop of only 88.7 Pa, which were 29.68 and 22.04%, respectively, higher than those of the pure CA film. It was noticed that the hydrophobicity and mechanical strength were also improved.