Calcium Phosphate Bioceramics with Various Porosities and Dissolution Rates

Porous bioceramics, such as hydroxyapatite (HA), tricalcium phosphate (TCP), and biphasic HA/TCP, were fabricated using the polyurethane sponge technique. The porosity of the ceramics was controlled by a multiple coating of the porous body. When a porous body was produced by a single coating, the porosity was ∼90%, and the pores were completely interconnected. When the sintered body was coated five times after the porous network had been made, the porosity decreased to 65%. As the porosity decreased, the strength increased exponentially. The TCP exhibited the highest dissolution rate in a Ringer's solution, and the HA had the lowest rate. The biphasic HA/TCP showed an intermediate dissolution rate.     

电沉积法制备磷酸钙生物活性陶瓷涂层

综述了用电沉积法在金属生物材料表面涂敷磷酸钙生物活性陶瓷的工艺,分析了电沉积工艺的特点,并介绍了制备金属－羟基磷灰石复合涂层的复合电沉积工艺。     

Calcium Phosphate Glass-Ceramic Crown Prepared by Lost-Wax Technique

A calcium phosphate glass-ceramic crown for dentistry was developed. The glass is cast into the shape of the crown by the lost-wax technique and subsequently heat-treated to convert it into the glass-ceramic, which exhibits excellent mechanical strength. The fine structure of the glass-ceramic is similar to that of the enamel of a natural tooth, and its hardness is near that of enamel.     

Calcium Phosphate Cements Prepared by Acid–Base Reaction

We investigated the characteristics of calcium phosphate cements (CPC) prepared by an exothermic acid–base reaction between NH₄H₂PO₄-based fertilizer (Poly-N) and calcium aluminate compounds (CAC), such as 3CaO · Al₂O₃ (C₃A), CaO · Al₂O₃ (CA), and CaO · 2Al₂O₃ (CA₂), in a series of integrated studies of reaction kinetics, interfacial reactions, in-situ phase transformations, and microstructure development. Two groups were compared: untreated and hydrothermally treated CPC specimens. The extent of reactivity of CAC with Poly-N at 25°C was in the following order: CA > C₃A ≫ CA₂. The formation of a NH₄CaPO₄· x H₂O salt during this reaction was responsible for the development of strength in the CPC specimens. The in-situ phase transformation of amorphous NH₄CaPO₄· x H₂O into crystalline Ca₅(PO₄)₃(OH) and the conversion of hydrous Al₂O₃ gel →γ-AIOOH occur in cement bodies during exposure in an autoclave to temperatures up to 300°C. This phase transformation significantly improved mechanical strength.     

磷肥厂含磷废水处理制备过磷酸钙的研究

以磷肥厂含磷废水为原料,改进传统处理工艺,采用新型两段式沉淀法处理工艺得到含磷渣,再添加适量硫酸反应制备过磷酸钙。该工艺流程短、操作简便、磷回收率高,在处理含磷废水的同时,得到过磷酸钙,产品质量符合GB 20413-2006标准要求,经济效益明显,为磷肥企业含磷废水的处理利用提供有效途径。     

Determination of Calcium/Phosphorus Atomic Ratio of Calcium Phosphate Apatites Using X-ray Diffractometry

The properties of calcium phosphates of biological interest depend strongly on their calcium/phosphorus atomic ratios (Ca/P). Therefore, the precision for the determination of this ratio is crucial. We have investigated the accuracy of quantitative X-ray diffractometry (QXRD) analysis for the determination of Ca/P in compounds with Ca/P ranging from 1.5 to 2. For 1.5 < Ca/P < 1.667, a high accuracy is obtained with relative uncertainties on Ca/P values between 0.1% and 0.4%. In this domain of composition, QXRD is more accurate than classical wet methods. For 1.667 < Ca/P < 2, the precision is lower and wet chemical methods appear to be superior.     

全谱直读ICP光谱法测定磷酸氢钙中磷的含量

研究了电感耦合等离子体发射光谱（ICP－AES）测定磷酸氢钙中磷含量的分析方法，测量的精密度＜0．5％，与按国家标准方法测定结果对照表明，用该方法测定的结果准确，可靠。     

硅钙渣制备碱激发胶凝材料的机理研究

以水玻璃为激发剂,硅钙渣、矿渣微粉为原料制备得到了碱激发胶凝材料.分别采用XRD、IR、TG-DSC、ESEM等手段研究了试样不同龄期的反应产物及微观形貌特征.结果表明:主要反应产物为低Ca/Si比的C-(A)-S-H凝胶;这些C-(A)-S-H凝胶粒子相互分叉搭接,形成致密的三维蜂窝状网络结构;随着龄期的延长,硅钙渣中的β-C2S逐渐参与碱激发反应,产物C-(A)-S-H凝胶的聚合程度增大,基体致密程度提高.     

磷矿石中氧化钙含量的测定

在GB/T1871.4-1995中EDTA容量法的基础上 ,以 1+ 1氨水溶液调节试液酸度 ,加过量的EDTA标准溶液 ,以K .B混合液为指示剂 ,用ZnSO4标准溶液返滴定 ,求得试样中CaO含量 ,该法终点变色敏锐 ,容易检测     

利用磷石膏制备轻质高钙墙体材料的研究

本文采用了石膏制备出的α半水为基础研究制备高强轻质墙体材料,分别研究了水灰比,双氧水、激发剂、缓凝剂、表面活性剂掺量对石膏试块强度和轻质化的影响,使用扫描电镜(SEM)分析石膏试块表面和内部的结晶情况.试验确定在水灰比0.45,每1 kg浆料双氧水掺量3.00 mL、激发剂掺量0.20 g,缓凝剂掺量0.50‰、表面活性剂掺量0.10‰的最优工艺条件下,墙体材料试块干基抗压强度为5.20 MPa,干基抗折强度为2.31 MPa,体积密度为0.80 g/cm3,具有明显的轻质高强特性.     

饲料添加剂磷酸二氢钙

将饲料添加剂磷酸二氢钙与其它几种饲料添加剂磷酸钙盐在饲喂效果方面进行比较，显示出饲料添加剂磷酸二氢钙的最高生物学效价，在生产饲料添加剂磷酸二氢钙时，按反应过程中主物料所呈现的状态，对生产饲料添加剂磷酸二氢钙的方法进行分类比较。     

Development of Injectable Calcium Sulfate and Self-Setting Calcium Phosphate Composite Bone Graft Materials for Minimally Invasive Surgery

The demand of bone grafting is increasing as the population ages worldwide. Although bone graft materials have been extensively developed over the decades, only a few injectable bone grafts are clinically available and none of them can be extruded from 18G needles. To overcome the existing treatment limitations, the aim of this study is to develop ideal injectable implants from biomaterials for minimally invasive surgery. An injectable composite bone graft containing calcium sulfate hemihydrate, tetracalcium phosphate, and anhydrous calcium hydrogen phosphate (CSH/CaP paste) was prepared with different CSH/CaP ratios and different concentrations of additives. The setting time, injectability, mechanical properties, and biocompatibility were evaluated. The developed injectable CSH/CaP paste (CSH/CaP 1:1 supplemented with 6% citric acid and 2% HPMC) presented good handling properties, great biocompatibility, and adequate mechanical strength. Furthermore, the paste was demonstrated to be extruded from a syringe equipped with 18G needles and exerted a great potential for minimally invasive surgery. The developed injectable implants with tissue repairing potentials will provide an ideal therapeutic strategy for minimally invasive surgery to apply in the treatment of maxillofacial defects, certain indications in the spine, inferior turbinate for empty nose syndrome (ENS), or reconstructive rhinoplasty.     

微波烧结法制备TCP/TTCP复合生物陶瓷材料的研究

采用微波烧结方法制备TCP/TTCP复合磷酸钙生物陶瓷材料,以四水硝酸钙(Ca(NO3)2·4H2O)和磷酸氢二铵((NH4)2HPO4)为初始原料制备磷酸三钙(TCP)和磷酸四钙(TTCP).研究了当代PCP/TTCP(物质的量)配比为1:1时,不同的烧结温度对复合钙磷陶瓷的结构和晶相的影响.对烧结后的样品在模拟体液中进行了浸泡实验,监测了浸泡过程中的pH值变化,通过扫描电镜、X射线衍射分析对浸泡后试样的结构和晶相的变化进行了分析.结果表明微波烧结制备的磷酸钙生物陶瓷的主晶相是HA,其结构均匀,致密度较好.且在1200℃下微波烧结HA能稳定存在,陶瓷具有良好的表面生物活性.浸泡溶液的pH值变化幅度小(在7.40～7.72之间),接近中性.     

电石渣制备超细碳酸钙过程中的表面改性研究

以电石渣为原料,利用间歇鼓泡碳化法制备出碳酸钙。分别在不同的制备阶段加入钛酸酯偶联剂(JN117)对产品进行表面改性,发现在碳化过程中加入改性剂钛酸酯偶联剂JN117时,产品的白度有所降低,而吸油值降低明显,活化度则升高,表明此时改性效果较好。SEM表征表明,在碳化过程中加入改性剂时产品的分散性优于其它改性方法。     

磷石膏制备硫酸钙晶须的工艺研究

采用常压酸化法对磷石膏分别进行硫酸除杂和盐酸溶解,将磷石膏中的钙富集于溶解液中.再对溶液进行处理制备硫酸钙晶须,考察硫酸钙初始浓度、结晶温度及添加助晶剂种类和用量对硫酸钙晶须组成、结构和形貌的影响.实验结果表明:所制晶须均为二水硫酸钙晶须;以乙醇作为助晶剂所制备的晶须形貌最好.当乙醇的添加量为15 mL(即V乙醇∶V盐酸=1∶2)时所制备的晶须比较均一,平均直径为25 μm,平均长径比约为80.     

不同乙型肝炎表面抗原配制的免疫复合物的免疫原性

目的研究不同乙型肝炎表面抗原配制的免疫复合物(IC)的免疫原性,并进一步优选治疗性乙型肝炎疫苗最佳抗原。方法用不同重组乙型肝炎表面抗原(HBsAg)与不同的乙型肝炎表面抗体(anti-HBs)制备IC,分别免疫BALB/c小鼠,检测体液免疫及细胞免疫应答水平。结果IC诱生的抗-HBs效价、抗-HBsIgG2a/IgG1的比值及IFN-γ形成细胞数,YHB-IC组总体上略高于CHO-IC组,但差异无显著意义。结论IC的免疫效果优于单独HBsAg;不同乙型肝炎表面抗原配制的IC之间免疫原性差异无显著意义。     

普通过磷酸钙水萃取生产饲料磷酸氢钙

介绍了普通过磷酸水萃取生产饲料水萃取生产饲料磷酸钙的方法以及生产工艺流程中主要控制数据。该法工艺简单，脱氟方便，投资省，特别适用于中小型磷肥厂建立车间进行生产。