Synthesis, characterization, and thermo-mechanical properties of copper-loaded apatitic calcium phosphates

Abstract

Copper is well known as a classical transition metal used in heterogeneous catalysis. In this study, copper-loaded apatitic calcium phosphates were prepared using incipient wetness impregnation (IWI) and ionic exchange (IE) methods. The interaction between copper precursor (copper nitrate trihydrate, Cu(NO 3) 2 •3H 2 O) and apatitic calcium phosphate (CaP) depended strongly on the preparation method and the content of copper-loaded. Using IE, copper(II) cations (Cu 2+) were incorporated in the apatitic structure of CaP. The content of copper(II) cations seemed to be limited at about 2.2 wt.%. Calcination at 400°C had no influence on the solids obtained by the IE method. Using IWI, the deposition of a theoretical copper content of 2 wt.% led to the incorporation of copper(II) cations in the apatitic structure of CaP by IE with Ca 2+ , despite the low quantity of aqueous solvent used. Therefore the resulting product was similar to that obtained by IE. When the theoretical copper content rose to 20 wt.%, the entire amount of copper precursor molecules were largely deposited, which resulted in the formation of copper oxide particles (CuO) after air calcination at 400°C. Thermo-mechanical analysis study showed that the presence of copper oxide did not modify the thermal shrinkage of the initial calcium phosphate. On the other hand, thermal shrinkage was much more important in the case of CaP substituted with copper(II) cations.

Synthesis of carbon nanotubes/hydroxyapatite composites using catalytic methane cracking

“…For the growth of CNTs, the synthesized Ca-HA was firstly functionalized by the deposition of well-dispersed nickel particles on its surface using the standard incipient wetness impregnation method. [29,30] An aqueous solution of Ni(NO 3 ) 2 was added dropwise to the Ca-HA powder in order to get a consistent mixture. The concentration of Ni(NO 3 ) 2 solution was calculated in order to reach the desired nickel content in the final solid product (5 wt.%).…”

Metal-doped apatitic calcium phosphates: preparation, characterization, and reactivity in the removal of hydrogen sulfide from gas phase

“…The removal of H 2 S at high temperature, for example for the purification of hot syngas generated from thermal gasification of biomass, seems to be particularly interesting because of high thermal stability of hydroxyapatite-based materials, as demonstrated previously. [30] …”

“…The synthesis of metal-doped sorbents was the same as described elsewhere by Galera Martinez et al [30] Using CEX method (cation exchange), 39 g of CaP powder were put into 2 L of the metal nitrate solution of defined concentration under stirring at 500 rpm. After 4 h of contact, the suspension was filtered and the resulting solid was washed several times with permuted water and dried in ambient air.…”

Antibacterial Cu-Doped Calcium Phosphate Coating on Pure Titanium

“…Therefore, the Cu content in the coating is evidently increased. When the doping amount of Cu 2+ in HA reaches saturation, 13) Cu 2+ can directly obtain electrons at the cathode to generate Cu through a reduction reaction. This explains why a Cu diffraction peak is detected in the XRD pattern.…”