Electrospun poly(vinyl alcohol)/α-zirconium phosphate nanocomposite fibers

Abstract

Poly(vinyl alcohol) (PVA)/α-zirconium phosphate (ZrP) polymer nanocomposite (PNC) fibers were successfully prepared by a simple and low-cost electrospinning process. ZrP nanoparticles with two different dimensions, that is, ZrP-500 with a lateral dimension of ∼320 nm and an aspect ratio of ∼500 and ZrP-1500 with a lateral dimension of ∼950 nm and an aspect ratio of ∼1500, were utilized to illustrate the size effect on the electrospun nanofibers. In order to obtain defect-free, uniform PNC fibers, a number of parameters including polymer concentration, feed rate, applied voltage and working distance between the needle tip and the fiber collecting substrate were investigated. Scanning electron microscopic morphological analysis showed smooth and nonwoven electrospun nanofiber mat. Strong intermolecular interactions between the PVA matrix and the included ZrP nanofillers were revealed by the attenuated total reflectance Fourier transform infrared spectroscopy. The incorporation of ZrP nanofillers drastically improved the thermal stability of the PNC fibers. Results of thermogravimetric analysis demonstrated a clear thermal stability dependence on the aspect ratio of the crystalline ZrP nanofillers. The degradation temperature was increased by 90°C for the ZrP-1500 and 60°C for ZrP-500, when the loading level was increased from 1 wt% to 5 wt%. Furthermore, the viscoelastic properties of the PNC solutions were studied by the rheometer. The solutions with higher loading of the nanofiller exhibited higher viscosity and demonstrated different fluid nature when compared with the solutions at lower loading level.