Abstract:

In order to develop nanofibers for air filtering, polyacrylonitrile (PAN) nanofiber membranes were prepared by electrospinning. The influence of spinning solution concentration and electrospinning voltage on microstructure of the electrospun nanofibers, as well as the infouence of membrane thickness on filtration efficiency and pressure drop were investigated. The results shown that when the concentration of PAN spinning solution is 12 wt% and the voltage was 20 kV, the well-distributed nanofibers with mean diameter of 230 nm can be formed. The pressure drop increased from 121.93 Pa to 591.75 Pa when membrane thickness increased from 18 μm to 35 μm, while the filtration efficiency of DOP aerosol particle sized 0.33 μm raised from 81.78% to 99.24%. Besides, mechanical properties and pore size distribution determined by the fiber diameter with the better filtration efficiency were tested. Results revealed that its elastic modulus is 223.67 MPa, elongation at break is 51.96%, tensile fracture stress is 5.93 MPa, tensile strength is 7.77 MPa, tensile yield stress is 2.79 MPa, and the average pore size tested by bubble pressure method is 2.0643 μm.

Key words: ployacrylonitrile, electrospinning, air filtration, nanofiber