Investigation of various fatty acid surfactants on the microstructure of flexible hydroxyapatite nanofibers

Abstract

Flexible hydroxyapatite nanofibers (HANFs) exhibit great potential in various biomedical fields, especially in bone tissue regeneration as a load-bearing implant material. In this study, flexible HANFs have been successfully synthesized through a solvothermal method using different kinds of fatty acids, including linoleic acid, oleic acid, ricinoleic acid, stearic acid, and palmitic acid, as surfactants. The influences of various fatty acids on the composition, thermal stability and microstructure of the products are investigated by XRD, FT-IR, TG, FESEM, EDS and TEM. The as-prepared flexible HANFs with aspect ratios up to >10 000 are composed of multiple short nanofibers with low Ca/P ratios (∼1.3), high crystallinity (>83%) and diameters of ∼10 nm. However, microrods do not exist in the final products by using oleic acid or palmitic acid as surfactants, and products with a higher crystallite size are found when ricinoleic acid or stearic acid is used. The method reported herein may be applicable for the synthesis of HANFs using other fatty acids as surfactants.