Mechanosynthesis of carbonate and lithium co-substituted hydroxyfluorapatite. (June 2022)

• Record Type: Journal Article
• Authors: Hajji, Hanen; Le Gallet, Sophie; Saviot, Lucien; Ben Salem, Ezzedine; Millot, Nadine
• Is Part Of: Materials research bulletin. Volume 150(2022)
• Publication Date: 2022-06
• Subjects: Mechanosynthesis -- Nanoparticles -- Hydroxyfluorapatite -- Li+ and CO32- substitution -- Sintering; Materials -- Periodicals; Crystal growth -- Periodicals; Matériaux -- Périodiques; Cristaux -- Croissance -- Périodiques; Crystal growth; Materials; Periodicals; 620.11
• DOI: 10.1016/j.materresbull.2022.111750
• Languages: English
• ISSNs: 0025-5408

Abstract

Highlights: Hydroxyfluorapatite cosubstituted by Li + and CO3 2− was prepared by mechanosynthesis. XRD, IR, Raman, EDS, DLS, TGA and TEM were used to characterize the powders. The impact of substitution rate on purity and structural properties was investigated. The substituted sample with x = 1 was sintered by spark plasma sintering. After SPS, the crystallite size remains nanometric. Abstract: The presence of fluoride, lithium and carbonate group within hydroxyapatite occurring naturally within the body provides the basis for investigating the sintering ability of co-substituted hydroxyfluorapatites nanopowders for use as biomaterials. Ca10-x Lix (PO4 )6-x (CO3 )x (OH)F nanopowders, with x equal to 0, 0.5, 1, 1.5, 2 and 2.5 were prepared using mechanosynthesis and their extensive characterization was realized. Substitution causes contraction of the unit hexagonal cell along the a -axis and elongation along the c -axis, as well as a decrease in the degree of crystallinity of the powders, and an increase of the amounts of unreacted calcium and lithium carbonates. Crystallite sizes and strains, determined by the Halder & Wagner method, remain the same whatever x. Spectroscopic analyses show that B-type carbonated apatite is formed. Annealing at 500 °C improves the crystallinity of the apatite phase with low percentages of calcite and lithium phosphate as secondary phases ( x ≤ 2). Transmission electron microscopy observations show that untreated and calcined powders consist mainly of spherical nanoparticles. As-mechanosynthesized Ca9 Li(PO4 )5 (CO3 )(OH)F powder, sintered by Spark Plasma Sintering, densifies in the temperature range of 580 to 650 °C. The crystallite size remains the same than that of the untreated-powder (about 15 nm). Graphical abstract: Image, graphical abstract