Role of acid phosphate in hydroxyapatite lattice expansion.
Role of acid phosphate in hydroxyapatite lattice expansion.
复制标题
酸性磷酸盐在羟基磷灰石晶格膨胀中的作用。
DOI：
10.1007/bf02405294
复制
发表时间：
1984
影响因子：
4.2
通讯作者：
Holcomb,DW
中科院分区：
文献类型：
--
作者：
Young,RA;Holcomb,DW
关于人类牙釉质（TE）的哪些亚组分负责其晶体轴几乎0.02Å比纯羟基磷灰石（OHAp）长，并在加热时收缩到OHAp的问题仍然存在。通过对含有hpo4和“结构”水的合成OHAp的红外光谱和x射线衍射研究，我们得出结论，hpo4膨胀轴的速率为~ 0.0015Å/ wt %，但这远远小于可观测到的总收缩的一半。其余的，超过一半的轴向变化，可能只是部分归因于“结构性”H2O，部分归因于P2O7（由HPO4形成），从磷灰石的固溶体中产生。在160-240°C的温度范围内，用红外观察到的约90%的hpo4丢失，超过一半的p2o7作为一个单独的相被观察到，在该温度以上发展，并继续增加，直到500°C，实验的极限。hpo4的丢失伴随着结构OH离子位点的无序性或多样性的减少，这与最初与OH离子相邻的一些po4基团实际上是hpo4基团的观点一致。
Questions remain about which subcomponents of human tooth enamel (TE) are responsible for its crystallographicaaxis being nearly 0.02Å longer than that of pure hydroxyapatite (OHAp) and contracting to that of OHAp on heating. From infrared spectroscopic and X-ray diffraction studies of a synthetic OHAp containing HPO4and “structural” H2O, it has been concluded that HPO4expands theaaxis at the rate of ∼ 0.0015Å/ wt % but that this accounts for substantially less than one-half of the total observable contraction. The remaining, more than one-half of theaaxis change, may be only partially ascribable to “structural” H2O and partially to P2O7(formed from the HPO4), coming out of solid solution in the apatite. Some 90% of the HPO4observed with infrared is lost in the 160–240° temperature range and more than one-half of the P2O7observed as a separate phase is developed above that temperature and continues to increase all the way up to the 500°C, the limit of the experiments. The loss of HPO4is accompanied by reduction of disorder or variety in the structural OH ion sites, consistent with the view that initially some of the PO4groups neighboring the OH ions were actually HPO4groups.