Electrospinning of Poly-L-lactic Acid for Air Filter Application

Recently, nanofibrous air filters have received attention to remove air pollution, including
PM2.5, PM10 and volatile organic compounds (VOC), owing to their high surface area, high air
flow, high porosity and low thickness. Nowadays, most of nanofibrous air filters were produced
by electrospinning of synthetic polymers such as polyacrylonitrile (PAN), polypropylene (PP),
and polyvinylpyrrolidone (PVP). Their PM2.5 filtration efficiency have been reported in a range
of 80-98%. However, these air filters are not biodegradable. Thus, they can be accumulated as
waste and lead to environmental concern. Therefore, we aim to produce an ecofriendly air filter
from poly-L-lactic acid (PLLA) which is a bio-based and biodegradable polymer. In this work,
PLLA fibers were produced via electrospinning technique. The PLLA fibers were
characterized by FTIR spectroscopy, SEM and the tensile testing was also performed. It was
found that the diameter sizes of PLLA fibers were varied in from 527 to 1162 nm. The tensile
strength of electrospun PLLA was found to be 18.31 ± 1.01 MPa. The air filter property was
tested in a custom-built chamber. The PM2.5 removal efficiency of PLLA filter was
approximately 80% with quality factor of 0.06.