View Publication | CEMHTI CNRS UPR3079 Orléans France

F.Fayon, C.Duée, T.Poumeyrol, M.Allix, D.Massiot, 'Evidence of Nanometric-Sized Phosphate Clusters in Bioactive Glasses as Revealed by Solid-State 31P NMR', J. Phys. Chem. C 117 2283-2288 (2013) doi:10.1021/jp312263j

Bioactive glasses are able to form strong bonds to bone. This property, crucial for medical applications, depends on the glass composition and structure. Dissolution of phosphates in melt-quenched silicate glasses raises the question of chemical homogeneity and possible formation of clusters. A detailed structural characterization of the bioactive glasses is thus highly desirable. In this work, the nature of the distribution of phosphate units in a melt-quenched bioactive glass is elucidated for the first time using 31P spin-counting solid-state NMR experiments. The structure of a dense bioactive calcium silicate glass with 2.6 mol.% of phosphorus oxide is shown to exhibit nanometric-sized chemical and structural heterogeneities. Clear experimental evidences for the presence of phosphate clusters of five and six PO4 tetrahedral units embedded in the disordered polymeric silicate network are given.