Clermont Université, ENSCCF, Laboratoire des Matériaux Inorganiques, BP 10448, F-63000, Clermont-Ferrand, France.
Acta Biomater. 2010 Aug;6(8):3264-74. doi: 10.1016/j.actbio.2010.02.034. Epub 2010 Feb 25.
Four samples of composition Ca(10)(PO(4))(6-x)(SiO(4))(x)(OH)(2-x), with x=0.0, 0.1, 0.2 and 0.5, were prepared and characterized using powder X-ray and neutron powder diffraction, and (1)H, (31)P and (29)Si nuclear magnetic resonance (NMR) spectroscopy. The composition of the Si-substituted HAp phases was determined by joint Rietveld refinements from powder X-ray and powder neutron diffraction data. Taking into account electroneutrality, a chemical formula for the Si-substituted HAp phases with indication of the incorporated silicate amount is proposed. Solid-state (29)Si NMR confirms the presence of only Q(0) species, in good agreement with the presence of substituted HAp and beta-TCP phases only. Thanks to NMR spectroscopy, two types of protons in the Si-substituted HAp phase were identified, the new site corresponding to species engaged in hydrogen bonding with silicate anions. This allowed further refinement of the formulae for these phases with very good quantitative agreement for populations derived from the refinement and integration of NMR data.
制备了四个组成分别为 Ca(10)(PO(4))(6-x)(SiO(4))(x)(OH)(2-x)（其中 x=0.0、0.1、0.2 和 0.5）的样品，并用粉末 X 射线和中子粉末衍射以及 (1)H、(31)P 和 (29)Si 核磁共振 (NMR) 光谱对其进行了表征。通过粉末 X 射线和粉末中子衍射数据的联合 Rietveld 精修，确定了 Si 取代 HAp 相的组成。考虑到电中性，提出了一个 Si 取代 HAp 相的化学式，并指出了掺入的硅酸盐量。固态 (29)Si NMR 证实仅存在 Q(0)物种，这与仅存在取代的 HAp 和 β-TCP 相一致。得益于 NMR 光谱，在 Si 取代的 HAp 相中鉴定出两种类型的质子，新的位点对应于与硅酸盐阴离子形成氢键的物种。这使得这些相的化学式可以进一步细化，并且 NMR 数据的精修和积分得到的种群具有非常好的定量一致性。
