Abstract:

In order to develop nanofibers with efficient air filtration performance, polylactic acid (PLA) tree-like nanofiber membranes were prepared by electrospinning. The effects of solvent type, addition amount of tetrabutylammonium chloride (TBAC) and spinning voltage on the morphology and properties of fiber membranes were investigated. In addition, the effect of TBAC addition and fiber membrane thickness on filtration efficiency was also studied. The results show that when the solvent is dichloromethane, the PLA/ TBAC mass ratio is 8 ∶ 1, and the spinning voltage is 30 kV, the fiber membrane has obvious tree-like structure. The fracture stress and quality factor of fiber membrane with obvious tree-like structure are 23 MPa and 0. 068, respectively, which is higher than 5 MPa and 0. 059 of the pure PLA fiber membrane. With the increase of the TBAC content, the contact angle of fiber membrane decreases from 118° to 54. 5°. For PLA nanofiber membranes with distinct tree-like structure, when the thickness of the fiber membrane increases from 10 μm to 40 μm, both filtration efficiency and pressure drop increase, especially, when the film thickness is 20 μm, the filtration efficiency of the fiber membrane is 99. 89%, and the resistance is about 96. 08 Pa, which can meet the demand for efficient air filtration.

Key words: electrospinning, polylactic acid, tree-like nanofiber, filter performance