TITLE:
Morphology and Thermal Properties of Core-Shell PVA/PLA Ultrafine Fibers Produced by Coaxial Electrospinning
AUTHORS:
Raquel P. Gonçalves, Flavia F. F. da Silva, Paulo H. S. Picciani, Marcos L. Dias
KEYWORDS:
Core-Shell Fibers, Electrospinning, Poly(Lactic Acid), Poly(Vinyl Alcohol)
JOURNAL NAME:
Materials Sciences and Applications,
Vol.6 No.2,
February
15,
2015
ABSTRACT: Coaxial electrospinning process was used to produce biodegradable membranes made of coreshell
fibers of a poly(lactic acid) (PLA) shell and a poly(vinyl alcohol) (PVA) core. Scanning electron
microscopy analyses of these structures showed that the PLA shell can present certain porosity
depending on the process condition. FTIR-ATR and contact angle measurements also suggested
imprisonment of the PVA core within the PLA shell. This type of structure was also confirmed by
means of transmissions electron microscopy. The morphology of these fibers was dependent on
the flow rate of both core and shell solutions, and homogeneous and smooth surface was only attained
when the flow rate of the external PLA solution was 4 times the flow rate of the internal
PVA solution. The increase in the PLA solution flow rate increases the diameter of the core-shell
fiber which reaches up to 1.7 μm. Nevertheless, fibers with smaller average diameter could also be
produced (200 nm). These core-shell fibers presented improved hydrophilicity as compared with
monolithic PLA fibers.