Fabrication and characterization of PVA/SPI/Si[O.sub.2] hybrid fibres via electrospinning technique

In this work, an electrospinning technique was developed for the fabrication of poly(vinyl alcohol) (PVA)/soy protein isolate (SPI)/Si[O.sub.2] hybrid fibres with PVA, SPI and tetraethyl orthosilicate (TEOS) as precursors. The effects of Si[O.sub.2] content, sodium dodecylsulfate and electrospinning electrical field strength on the morphology and structure of the hybrid fibres were investigated. Scanning electron microscopy (SEM) showed that uniform hybrid fibres about 200 nm in diameter were obtained at a weight ratio of PVA to SPI 8:2, Si[O.sub.2] content 5.0 wt.%, sodium dodecylsulfate 0.6 wt.% and electrical field strength 0.90 kV [cm.sup.-1]. X-ray diffraction (XRD) patterns showed that the crystalline structure of PVA was somewhat destroyed as PVA was hybridized with SPI and Si[O.sub.2], and further destroyed under electrospinning process as the stretched molecular chains of the fibre solidified rapidly at high elongation rates, resulting in the amorphism of PVA/SPI/Si[O.sub.2] hybrid fibres. Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) showed that the components of PVA, SPI and Si[O.sub.2] nanoparticles were linked by hydrogen bonds or Si-O-C bonds in the hybrid fabric networks. Differential scanning calorimetry (DSC) tests showed that the presence of Si[O.sub.2] nanoparticles considerably improved the thermal stability of the hybrid fibres. Therefore, the PVA/SPI/Si[O.sub.2] hybrid fibres may have potential as a new fibre in dressings, tissue engineering or drug delivery. Keywords: Soy protein isolate, Poly (vinyl alcohol), Si[O.sub.2], Hybrid fibre, Electrospinning technique