Electrospinning of Polyacrylonitrile Nanofiber Membrane for Bacteria Removal

Abstract: Electrospinning is a popular method to obtain nanofibers. Polyacrylonitrile (PAN) nanofibers in the range of 50 to 750 nm were prepared by electrospinning of homogeneous viscous solutions with varied polymer concentration in 10 – 16% (w/v) range in N, N- Dimethylformamide (DMF). The morphology of fibers observed by Scanning Electron Microscopy (SEM) indicated that the morphology transformation from beaded fiber to cylindrical form occurred at 14%, and the average fiber diameter at this concentration is 379 ± 54 nm. The polyacrylonitrile nanofibers were characterized by the Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR). Differential Scanning Calorimeter (DSC) study of electrospun fibers revealed the presence of three thermal transitions in glass transition of PAN fibers. Membrane of 14% PAN nanofiber was subjected to vacuum for removal of air from the pores along with partial densification. This membrane was tested for bacteria reduction and found to eliminate model E. coli bacteria up to 99.9997%. In addition, membranes of different thicknesses in the range of 125 µm to 750 µm were also electrospun and flow rate of water (flux) was measured. It was found that the flux exponentially decreased with the increase in thickness due to the strong resistance to flow through nanosized pores