Mechanochemical synthesis and ionic conductivity of lanthanum phosphosilicate oxyapatites

Abstract

Lanthanum phosphosilicate apatites with the chemical formula Sr 10-x La x (PO 4 ) 6-x (SiO 4 ) x O, where 0 x 6, usually prepared by a solid-state reaction at about 1400 8C, were synthesized via the mechanochemical method at room temperature. The samples were characterized using powder X-ray diffraction, infrared spectroscopy and thermal analysis. The results showed that the prepared products were carbonated apatites and no secondary phase was detected. The realization of the milling under a controlled atmosphere can lead to oxyapatites containing no carbonates. The ionic conductivity of the Sr 6 La 4 (PO 4 ) 2 (SiO 4 ) 4 O sample was investigated by using impedance spectroscopy. The highest ionic conductivity value of 1.522 Â 10 À6 SÁcm À1 was found at 800 8C. In the investigated temperature range, the activation energy is of 0.85 eV.

Synthèse et caractérisation de strontium–calcium–lanthane apatites Sr7−xCaxLa3(PO4)3(SiO4)3F2 0 ≤ x ≤ 2

“…Il en est de me ˆme pour les apatites, alors que celle du compose ´Ca 6 La 4 (PO 4 ) 2 (SiO 4 ) 4 F 2 [46] est forme ´e de deux branches. En revanche, la courbe de Ca 6 La 4 (PO 4 ) 2 (-SiO 4 ) 4 O [47] ne comporte pas de cassure, bien que le lanthane soit aussi pre ´sent. Ceci conforte l'ide ´e que la rupture de pente est essentiellement due a `la nature de la liaison Sr/La-F.…”

Upconversion 3D Printed Composite with Multifunctional Applications for Tissue Engineering and Photodynamic Therapy

“…In order to improve bioactivity and osteoconductive properties of synthetic polymers, inorganic compounds have been incorporated into their polymeric constituent matrices. 31 PCL-based composites containing hydroxyapatite, Ca 10 (PO 4 ) 6 (OH) 2 , 32 or other calcium phosphate derivatives, such as octacalcium phosphate, 33 and tricalcium phosphate, 34 have demonstrated to improve the mechanical properties, bioactivity, biodegradability and biocompatibility of PCL. 35 Hence, PCL-based composites are potential candidate materials for 3D printing and bone tissue engineering.…”