Rapid formation of hydroxyapatite nanostrips via microwave irradiation

Hydroxyapatite (HAp) nanostrips were rapidly obtained during a mild microwave heating method. Applying microwave irradiation to Ca(NO₃)₂·4H₂O/CTAB/Na₂HPO₄ precursor solution, the HAp precipitation process was occurred directly and without common crystallographic transformations including dissolution and slow recrystallization. The cationic surfactant CTAB was used as a soft template to modify nucleation and growth process. TEM investigations showed that the fabricated nanostrips had a width and length of about 10 and 55 nm, respectively. The X-ray diffraction pattern revealed that the fabricated well-crystallized and high purity hydroxyapatite nanostrips had a pattern similar to the bone mineral. The FTIR spectrum of the synthesized HAp nanostrips confirmed the crystallization degree observed in X-ray diffraction pattern. Moreover, the effect of CTAB on formation mechanism of the fabricated nanostrips was investigated.