Template-Based Synthesis of Nanoporous Hydroxyapatite

Abstract

Hydroxyapatite (HAp) particles, a potential starting material for bone substitutes, with nanopores were synthesized in the presence of cetyltrimethylammonium bromide (CTAB) and P123 as cationic and nonionic surfactants as the structuring units. Effect of nonionic surfactant concentration on surface areas is also investigated. Based on N 2 adsorption-desorption isotherms investigation, surface area increased up to 50 m 2 /g by using P123 and 147 m 2 /g by using CTAB as porosity agent. Pore structure remained even after the removal of surfactant and calcinations at 400 • C.

Preparation of Porous Hydroxyapatite Using Cetyl Trimethyl Ammonium Bromide as Surfactant for the Removal of Lead Ions from Aquatic Solutions

“…The peaks associated to the FTIR spectrum of CTAB located in the range of 890–110 cm −1 could not be observed in the FTIR spectrum of HAp-CTAB composite due to broad bands present in this region and associated with PO 4 3− vibrations. The achieved results were in accordance with preceding studies [ 35 , 37 , 38 , 39 , 40 , 41 ] confirming the formation of the HAp-CTAB composite.…”

Cu-Doped 1D Hydroxyapatite as a Highly Active Catalyst for the Removal of 4-Nitrophenol and Dyes from Water

“…It was proposed that the carbonate group was formed during the synthesis operations by a reaction between ambient CO 2 and the solution . In addition, two bands were detected at 2853 and 2923 cm –1 and can be designated to the C–H vibration, which indicates the existence of CTAB surfactant in HAP . The FTIR spectra of the Cu/HAP nanocomposites, on the other hand, are similar to the spectrum of 1D HAP, where only HAP’s distinctive bands can be found.…”

“…The Cu 2p′s high-resolution spectrum ( Figure 3 f) revealed two peaks with the bonding energy values of 932.1 eV (Cu 2p 3/2 ) and 952.1 eV (Cu 2p 1/2 ), which were characteristic for zero-valent Cu. 40 …”

“…The peaks at 289.6 and 286.6 eV shifted to 290.5 and 287.2 eV, respectively, in the 0.7% Cu/HAP nanocomposite. The Cu 2p′s high-resolution spectrum (Figure f) revealed two peaks with the bonding energy values of 932.1 eV (Cu 2p 3/2 ) and 952.1 eV (Cu 2p 1/2 ), which were characteristic for zero-valent Cu …”

Synthesis and characterisation of 3-dimensional hydroxyapatite nanostructures using a thermoplastic polyurethane nanofiber sacrificial template

“…During pyrolysis process, the template decomposes into gases, such as CO 2 and HO, leading to the formation of pores. 39 Since the melting temperature of TPU is high (195-205 C), gradual increase in pyrolysis temperatures allows gradual decomposition and diffusion of the polymeric material into the HAp matrix without any pressure build-up. 40 However the rate of decomposition is dependent on the concentration of the TPU immobilised between a unit area of HAp matrix which ultimately decides the extent of diffusion into the HAp in that unit area.…”