海水鲈鱼硬体组织中羟基磷灰石的结晶特性

摘要

Biominerals exist in scale,fin and tooth of seawater Lateolabrax Japonicus.In this paper,the crystallographic characteristics of the inorganic mineral phase existing in scale,tooth and bone (fin,sphenoid,backbone) from seawater Lateolabrax Japonicus were investigated by means of X-ray micro diffractometry (XRMD),transmission electron microscopy (TEM),environmental scanning microscopy (ESEM) and energy dispersive spectrometry (EDS).XRMD can well help to obtain valuable structure information by ways of in-situ and non-destruction measurements,and hence it is a more suitable method than powder diffraction in biomineral studies.The results show that the crystal phase in these hard tissues is sole hydroxylapatite (HAP).The chemical composition characteristics of HAP in hard tissues is lack of Ca and rich in P except sphenoid.Refined lattice parameters of HAP show that in scale:a =0.94210.9461nm and c=0.6844 0.6907nm and the closer to the scale base,the value of lattice parameters is closer to that of the scale base,in bone:a=0.9438 0.9492nm and c=0.6873 0.6887nm and in tooth:a=0.9470nm and c=0.6883nm.The coherent domain sizes calculated from the Scherrer equation are Dscale =9.4～14.1nm,Dbone=16.2～18.3nm and Dtooth =15.1nm.From bone to tooth to scale it shows a crystallinity sequence from good to poor.X-ray diffraction patterns and textural index R values indicate that all HAPs in hard tissues of Lateolabrax Japonicus have a preferring orientation along crystallographic c axis.The crystallographic charateristics of biominerals (grain size,crystallinity and preferring orientation) are designed by tissue function and controlled by organic matrix to provide good mechanical performance.%海水鲈鱼硬体组织的鳞片、几种骨骼和牙齿均含有生物矿物.运用X射线微区衍射、透射电镜、扫描电镜与能谱测试技术对其做了成分与结构方面的探究.其中X射线微区衍射技术能够无损、原样、有效的获取生命微晶体的结构信息,适合生物矿物研究.结果表明硬体组织中的矿物相均为羟基磷灰石,除蝶骨外,其余组织的羟基磷灰石化学成分呈现缺Ca富P的特征.晶胞参数修正结果得到鳞片中羟基磷灰石a=0.9421～0.9461nm,c=0.6844～0.6907nm,并且,越靠近鳞基,越接近鳞基处的晶胞参数;骨骼中a-0.9438～0.9492nm,c=0.6873～0.6887nm;牙齿中a=0.9470nm,c=0.6883nm.透射电镜观察羟基磷灰石为纳米级别晶粒,由Scherrer公式计算得到晶粒大小为D鳞=9.4～14.1nm,D骨=16.2～18.3nm,D牙=15.1nm,骨骼中羟基磷灰石晶体结晶度最好,其次为牙齿,鳞片中的结晶度最差.X射线衍射图及取向因子R计算结果表明,牙齿、鳞片和骨骼中羟基磷灰石晶体均趋向沿结晶学c轴择优取向生长特点.生物矿物结晶特性(晶体尺寸、结晶度及择优取向)是由组织功能决定并由有机基质调控的结果,以提供生命体良好的机械性能.