Crystal Structure of Hydroxyapatite Nanorods Synthesized by Sonochemical Homogeneous Precipitation

Abstract

Using a homogeneous precipitation method in an ultrasound field, we synthesized nanosized, platelike hydroxyapatite (HAp). The internal structure of these platelike formations consists of specifically oriented and laterally connected nanorods. The synthesized HAp nanorods have a length of about 500 nm and a diameter of about 100 nm. A closer inspection of the microstructure of a single nanorod revealed a highly regular and defect-free lattice with unique crystallographic plane orientations. The obtained structure was related to the influence of the ultrasound on the growth mechanism. The samples were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM).

Effect of dilute gelatine on the ultrasonic thermally assisted synthesis of nano hydroxyapatite

“…The images show small spherical particles agglomerated into clusters. The Gel-HAP particle size is similar to a previous study [34] but the topography is different to the pure nano HAP synthesized by use of ultrasound irradiation. The nano particles in Gel-HAP are more agglomerated into larger clusters and it appears that there are various different agglomerations of nano sized pores in between the fine particles.…”

“…In the area of sonochemical synthesis of HAP, Jevtic et al used of unique properties of sonocrystallisation to manufacture nanorods of HAP with a high-intensity (750W system) ultrasound system [34]. In addition, a recent study by Ethirajan et al in 2008 has shown the value of using high-powered ultrasounds in combination with a high concentrated solution of gelatine to generate GEL-HAP nanospheres by a reverse micellar method [35].…”

Nanoscale conversion of chlorapatite into hydroxyapatite using ultrasound irradiation

“…However, a decrease of particle dimension is also observed with pure HAp particles prepared using HNO 3 after a similar ultrasound treatment. Several previous reports have demonstrated the ability of ultrasound to tune HAp particle size but these studies were devoted to particle growth from Ca 2+ and phosphate salts [13][14][15][16][17][18][19][20][21] and often describes a continuous process occurring from an amorphous calcium phosphate phase to crystalline HAp. In these works, decrease of particle size upon irradiation was attributed to the formation of hot spots resulting from cavitation bubbles collapse that favor nucleation events.…”

“…Therefore many physical and chemical routes have been developed to obtain phosphocalcic apatites as high surface area powders from inorganic salts [12]. Of particular interest here are sonochemistry routes that allow control of the particle size and crystallinity through the modulation of irradiation power and duration [13][14][15][16][17][18][19][20][21]. As a more sustainable alternative, a process allowing for the conversion of natural phosphate into porous hydroxyapatite (Ca 10 (PO 4 ) 6 (OH) 2 ) was recently described [22,23].…”

Electrophoretically Deposited Multiwall Carbon Nanotubes (MWCNTS) and Hydroxyapatite (HA) on Stainless Steel (SS): Effective Biomaterial for Orthopedic Implant Applications

“…However, HA have poor mechanical properties as it has limitation in forming into complex shapes with control microstructures [3,[5][6][7]. MWCNTs are attractive for biomedical applications especially for developing nanofibrous bioactive surfaces with HA for its extraordinary high mechanical strength and nano-scale morphology [8][9][10][11].…”