贝壳韧带微结构的高分辨扫描电镜研究

采用高分辨SEM及XRD对合浦珠母贝韧带进行了研究,结果表明,合浦珠母贝韧带无机相主要由文石组成.韧带具有明显的层状结构,同一生长层及相隔生长层中文石纤维呈一致定向排列,而相邻生长层文石纤维的定向明显不同,呈“交叉棱柱层”结构样式.合浦珠母贝韧带中文石纤维的直径为80~90 nm,具有典型的2D光子晶体结构特征.     

均相法制备文石型碳酸钙晶须

在不加入任何结晶控制剂的条件下,采用CaCl2和Na2CO3的稀溶液并加的均相反应法制得了具有较好光滑性和长径比、分布均一的文石型碳酸钙晶须。其最佳工艺条件为:CaCl2与Na2CO3溶液浓度为0.025mol/L,滴加速度为1.20ml/min,滴管直径为3mm,搅拌速度为500r/min。     

Dynamic analysis of preferential orientation of arasonite crystals in nacre from mollusk shell

Based on the scanning electron microscope （SEM） observations, it is confirmed that the nacre is composed of aragonite crystals and organic matrix with interlaced arrangement, showing ordered ＂brick-mortar＂ structure. The dynamic analysis of preferential orientation of aragonite crystals in the nacre from the abalone （Haliotis diverscolor supertexta） with different shell ages is systematically investigated using X-ray diffraction （XRD） and high resolution transmission electron microscope （HRTEM）. Experiments reveal that, in the nacre from the juvenile mollusk shell, there exist three kinds of orientations of aragonite crystals： （113）, （002） and （012）. However, along with the growing of the mollusk shell, the intensity of （012） and （113） becomes weak, and the （002） becomes the preferred crystal orientation of aragonite in the nacre from the adult mollusk shell, which means that the c axis of aragonite crystals is perpendicular to the nacreous layers. The results obtained show that the nacre possesses a highly ordered structure at the micrometer/nanometer mulUscale levels.     

Dynamic analysis of preferential orientation of aragonite crystals in nacre from mollusk shell

Based on the scanning electron microscope (SEM) observations, it is confirmed that the nacre is composed of aragonite crystals and organic matrix with interlaced arrangement, showing ordered "brick-mortar" structure. The dynamic analysis of preferential orientation of aragonite crystals in the nacre from the abalone (Haliotis diverscolor supertexta) with different shell ages is systematically investigated using X-ray diffraction (XRD) and high resolution transmission electron microscope (HRTEM). Experiments reveal that, in the nacre from the juvenile mollusk shell, there exist three kinds of orientations of aragonite crystals: (113), (002) and (012). However, along with the growing of the mollusk shell, the intensity of (012) and (113) becomes weak, and the (002) becomes the preferred crystal orientation of aragonite in the nacre from the adult mollusk shell, which means that the c axis of aragonite crystals is perpendicular to the nacreous layers. The results obtained show that the nacre possesses a highly ordered structure at the micrometer/nanometer multiscale levels.     

莆田和晋江县全新世海滩岩与砂丘岩的探讨

福建莆田、晋江两县的苦鹅头、后石井等地,前人所指的海滩岩中,有一部分其实是砂丘岩;时代为中晚全新世,~(14)C年代测定为1881±81——4820±120年. 海滩岩向海倾斜8°—11°,层面发育溶沟、不规则浅盆等微地貌.颗粒分选差,以中粒石英砂为主,多含砾石,常见海绿石团粒.生物贝壳多为完整个体,石英砂表面见V形撞击坑.胶结物为文石和高镁方解石. 砂丘岩直接覆在花岗岩风化壳之上,前积层高角度倾斜(30—35°).颗粒分选好,以中细粒石英砂为主,多贝壳碎片,石英表面具碟形坑,胶结物为亮晶方解石,具新月型、悬垂组构. 二者的地球化学特征也不相同.     

Extraction and Purification of Matrix Protein from the Nacre of Pearl Oyster Pinctada fucata

A soluble matrix protein P14 with an apparent molecular mass of 14.5 kDa was isolated from fragmented nacre of pearl oysters （Pinctada fucata） treated with 10% NaOH solution to investigate the nacre matrix proteins and their effect on the CaCO3 crystal. The protein was characterized by gel exclusion chromatography and reversed-phase high performance liquid chromatography after demineralization by 10% acetic acid. The X-ray diffraction pattern of P14 crystals indicates that P14 plays an important role in nacre biomineralization. P14 can induce aragonite formation, stimulate CaCO3 crystal formation, and accelerate aragonite precipitation. Heating of the acid insoluble nacre residue, which was named conchiolin, in 10% sodium dodecyl sulfate solution supplemented with 10% β-mercaptoethanol solution for 10-20 min at about 100℃ gave two other soluble proteins having molecular masses of 19.4 kDa and 25.0 kDa. The present study suggests that these two proteins are linked to the insoluble organic matrix by disulfide bridges because the extraction yield increases when β-mercaptoethanol is added to the medium.     

文石晶须的碳酸化合成工艺研究

利用在加有ＭｇＣｌ２ 的石灰乳悬浊液中进行碳酸化的方法,合成了文石ＣａＣＯ３ 晶须,晶须直径在１ ～２ μｍ ,长径比在１０ ～４０ 之间．详细研究了ＭｇＣｌ２ 的浓度、悬浊液初始ｐＨ 值、反应温度及搅拌速度等工艺条件对沉淀ＣａＣＯ３ 晶型的影响,并初步探讨了ＣａＯ 的活性对文石晶须形态习性的影响．利用Ｘ 衍射分析手段对沉淀ＣａＣＯ３ 晶型进行了定量测定．实验表明：在悬浊液初始ｐＨ 值为９ 左右,反应温度为６０ ℃以上及搅拌速度为２４０ ｒ／ｍｉｎ 的条件下,可制备出均一的文石ＣａＣＯ３ 晶须     

贝壳中文石晶体择优取向的XRD分析

贝壳珍珠层独特的结构是其优异力学性能的重要原因.采用X射线衍射法(XRD)对贝壳珍珠层及柱状晶的晶体结构及择优取向进行了详细的探讨.结果表明:珍珠层中文石晶体在沿珍珠层面上存在两种定向排列,即(002)和(012),具有择优取向性,柱状晶层结构的无序性比珍珠层大.     

珍珠中碳酸钙与有机基质之间相互作用的研究

首次利用傅里叶变换红外光谱法对珍珠进行了表征,从碳酸钙红外谱带的位置及形状的变化直接证实了珍珠中亚微米级文石型碳酸钙晶体与有机基质界面之间存在着较强的络合作用。结合ICP-AES成分分析和SEM形貌分析,表明了上述络合作用正是珍珠形成高度有序的层状结构、且具有高强度、高韧性的化学本质。     

珍珠层作为骨修复材料的研究进展简

寻找和研制理想的骨修复材料一直是生物材料研究的热点之一。珍珠层作为生物骨替代材料,其优势在于含有具有诱导成骨作用的有机成分、合适的降解性能以及与人骨组织接近的力学性能。本文综述了珍珠层的结构、无机成分、有机成分、细胞相容性和生物降解性,这些研究结果表明,珍珠层具有很好的生物相容性。同时还分析了珍珠层作为骨修复材料存在的问题,展望了珍珠层作为骨修复材料应用的前景。