Synthesis and characterisation of 3-dimensional hydroxyapatite nanostructures using a thermoplastic polyurethane nanofiber sacrificial template

In this study, we report a facile synthesis of shape controlled three dimensional hydroxyapatite nanostructures (HAp) using a sacrificial thermoplastic polyurethane (TPU) nanofiber template. The TPU nanofibers synthesised using an electrospinning process were used as a template during the HAp synthesis through a precipitation process. Various HAp morphologies including distinctly placed cylindrically porous HAp architecture, coral reef like, tightly packed fibrous sheet like and nanofiber like were synthesised using the TPU nanofiber template. All the synthesised HAp were characterized using appropriate techniques like Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) attached with selected area electron diffraction (SAED), energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). The morphology, pore arrangement and the particle size of the HAp varied significantly with varying dimensions of the template and the template available per unit area of HAp. Hence, we have achieved four different 3D HAp morphologies using a single type of TPU nanofiber template. The TPU templated HAp nanostructures were more biodegradable than the control HAp.