Ultralong hydroxyapatite nanofibers/organics composite film for improving its mechanical property: Effect of proportions

Abstract Ultralong hydroxyapatite nanofibers (UHANFs) have received much more attention and been widely used in recent years for their inherent size‐dependent properties. However, the intrinsic agglomeration and brittleness of this material limited its application in some aspects. To overcome the agglomeration of UHANFs and instability of the molding slurry, a model was established inspired by the zeta potential and DLVO theory. The model was of utmost importance to provide a theoretical basis to link potential changes and material properties, and the most desirable state was achieved when the solid content was 2 wt%. In addition, the composites of UHANFs and organics could resolve part of the brittleness problem. Herein, we proposed a simple and environment‐friendly approach to manufacturing the biomimetic UHANFs/(chitosan‐gelatin) composite films. The synthesized products with different proportions of UHANFs were characterized by scanning electron microscopy (SEM), X‐ray diffraction (XRD), Fourier transform infrared (FTIR), thermogravimetric analysis (TGA), water vapor transmission rate (WVTR), swelling, and mechanical studies. The results showed that the ratio of UHANFs to organic matter had a profound influence on the combination properties of the composites. When the UHANFs content reached 70% in the films, the tensile strength and Young's modulus were 66.7% and 70.5% higher than that of samples containing 80% UHANFs. The respectable biological and mechanical properties of these films made them have the potential application in bone defect repair.