Apatite forming ability of Ti-HA-MWCNTs composite

The establishment of biocomposites of titanium (Ti) with a bioactive material, like hydroxyapatite (HA), as well as multi-walled carbon nanotubes (MWCNTs), is introduced as a substitute to enhance the response in the tissue-implant interface. This research investigated the effect of MWCNTs addition on the bioactivity properties of Ti-HA composite made by mechanical alloying and powder metallurgy. MWCNTs with varying contents (5 and 10 wt.%) were prepared. After milling the powders at 200 rpm for 2 h, the composite was isostatically compacted before sintering at 1000 °C for 2 h. The bioactivity properties and its morphology were investigated using immersion test and scanning electron microscope (SEM), respectively. The results indicate that higher MWCNTs content is associated with increased apatite weight and growth. The composite containing 10 wt.% MWCNTs exhibited a weight gain of 1.72%, which was higher than that of the 5 wt.% MWCNTs composite (1.56%). A higher MWCNTs content increased apatite weight from 0.02 g (5 wt.% MWCNTs) to 0.03 g (10 wt.% MWCNTs). The composite surface with 10 wt.% MWCNTs had more pronounced apatite coverage, which was mostly made up of spherical crystals. According to this finding, the Ti-HA composite with 10 wt.% MWCNTs showed higher bioactivity, as evidenced by increased apatite formation and improved bioactivity properties.