Data from: Synthesis, characterization and modelling of zinc and silicate co-substituted hydroxyapatite

Experimental chemistry and atomic modelling studies were performed here to investigate a novel ionic co-substitution in hydroxyapatite (HA). Zinc, silicate co-substituted HA (ZnSiHA) remained phase pure after heating to 1100°C with Zn and Si amounts of 0.6 wt% and 1.2 wt%, respectively. Unique lattice expansions in ZnSiHA, silicate Fourier transform infrared peaks and changes to the hydroxyl IR stretching region suggested Zn and silicate co-substitution in ZnSiHA. Zn and silicate insertion into HA was modelled using density functional theory (DFT). Different scenarios were considered where Zn substituted for different calcium sites or at a 2b site along the c-axis, which was suspected in singly substituted ZnHA. The most energetically favourable site in ZnSiHA was Zn positioned at a previously unreported interstitial site just off the c-axis near a silicate tetrahedron sitting on a phosphate site. A combination of experimental chemistry and DFT modelling provided insight into these complex co-substituted calcium phosphates that could find biomedical application as a synthetic bone mineral substitute.本研究开展了实验化学与原子模拟研究，以探究羟基磷灰石(hydroxyapatite, HA)中的新型离子共取代现象。锌-硅共取代羟基磷灰石(zinc silicate co-substituted HA, ZnSiHA)在加热至1100℃后仍保持纯相，其中锌与硅的质量占比分别为0.6 wt%与1.2 wt%。ZnSiHA独特的晶格膨胀、硅酸盐特征傅里叶变换红外峰以及羟基红外伸缩区域的变化，表明锌与硅酸盐在ZnSiHA中发生了共取代。采用密度泛函理论(density functional theory, DFT)对锌与硅酸盐掺入羟基磷灰石的过程进行了建模。研究考虑了多种取代场景：锌取代不同钙位点，或占据沿c轴的2b位点——该位点曾被推测存在于单取代ZnHA中。在ZnSiHA中能量最稳定的位点为锌占据此前未被报道的间隙位点，该位点紧邻c轴，且位于占据磷酸根位点的硅氧四面体附近。实验化学与DFT建模的结合，为这类复杂共取代磷酸钙材料提供了机理洞察，这类材料可作为合成骨矿物替代材料应用于生物医学领域。