Morphology and crystallinity of the nanosized hydroxyapatite synthesized by hydrolysis using cetyltrimethylammonium bromide (CTAB) as a surfactant

The biodegradable hydroxyapatite (HA) was synthesized by hydrolysis and characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electron diffraction (ED). The HA synthesized from CaHPO4 center dot 2H(2)O(DCPD) in 2.5M NaOH(aq) at 75 degrees C for 1 h had a size of 50 nm in width and 100 nm in length. However, the HA aggregates synthesized from DCPD in 2.5M NaOH(aq) with cetyltrimethylammonium bromide (CTAB) as a surfactant were elongated. When the CTAB concentration was increased from 1 x 10(-4) to 1 x 10(-2) M, the synthesized HA became thinner to a size of 5-20 nm in width and 50 nm in length. For thinner HA aggregates, longer agglomerates were aligned in the synthesis without the CTAB surfactant. (C) 2004 Elsevier B. V. All rights reserved.