Fabrication and characterization of fibrous HAP/PVP/PEO composites prepared by sol-electrospinning

Abstract

Fibrous composites of hydroxyapatite (HAP)/polyvinylpyrrolidone (PVP)/polyethylene oxide (PEO) with good mechanical properties were successfully prepared by a sol-electrospinning process. As HAP nanoparticles could not disperse well in polymer aqueous solution, a modified procedure was presented to firstly prepare HAP sol. The PVP and PEO polymers were then directly dissolved in the HAP sol solution for electrospinning, which was based on completely miscible solutions. The morphology and structure of the electrospun fibrous composites were investigated by XRD, SEM, TEM and FTIR. It was of interest to observe that large numbers of HAP nanoneedles were preferentially oriented parallel to the longitudinal direction of the electrospun PVP–PEO nanofibers when a relatively small amount of HAP was used. When there was a large amount of HAP, the agglomeration of needle-like HAP particles could stretch out of the fibers. This could reduce the electrical charge carried by the liquid jet, and make some agglomerated HAP particles randomly arrange on the edge of the jet, with the result that some protuberances existed on the surface of the fibers. Mechanical testing demonstrated that the incorporation of HAP into the PVP–PEO matrix led to significantly better tensile properties compared to those of the pure electrospun polymer membrane, and the incorporation of 60 wt% HAP into the matrix of PEO–PVP nanofibers led to a higher tensile strength of 19.20 ± 0.09 MPa and a percentage of elongation of 11.64 ± 0.31%, respectively. Based on the study, the combination of PVP–PEO and HAP could be promising for application as scaffolds for bone tissue engineering.