用热化学反应法制备金属陶瓷涂层工艺的研究

研究用热化学反应法在金属表面制备陶瓷涂层的工艺，并对涂层的相结构及显微组织进行分析。结果表明，采用该工艺可以在金属表面获得连续、致密且与基体结合良好的陶瓷涂层。腐蚀试验证明，采用本工艺在４５号钢表面涂覆陶瓷后可使其抗蚀性显著提高。     

多孔两相磷酸钙生物陶瓷的制备及其性能研究

介绍了以钙直力磷酸盐为原料经化学合成磷酸钙盐胶体的方法制成多孔两相磷酸钙盐陶瓷。试验结果表明，经发泡成型，高温热处理和烧结后的两相磷酸钙陶瓷其力学性能优于羟基磷酸钙并具有良好的生物相容性。     

磷酸钙纳米生物材料的合成及烧结研究进展

纳米磷酸钙陶瓷由于其独特的纳米效应,力学性能和生物活性大幅度提升,成为生物医用材料领域研究热点。纳米磷酸钙陶瓷制备的两大难点在于纳米粉体的合成和陶瓷的烧结。对现有的纳米磷酸钙粉体合成和纳米陶瓷烧结工艺进行了全面的综述,归纳分析了不同过程工艺参数对纳米粉体和陶瓷晶粒的影响,并对今后的研究进行了展望。     

Functional Materials for Bone Regeneration from Beta‐Tricalcium Phosphate

Biodegradable ceramics of β‐tricalcium phosphate (β‐TCP, Ca₃(PO₄)₂) are widely used as bone regeneration materials. The goal is a complete regeneration of the bony defect (restitutio ad integrum = full recovery). Different bioceramics made of β‐TCP show fundamental differences in terms of phase purity, primary particle size, stability, porosity, solubility and therefore biodegradation of the material. Cerasorb® is a bioceramic consisting of phase pure β‐TCP. The primary particle size in connection with a stable sinter structure forms a porous biomaterial which is optimised in the functional surface, porosity and resorption/degradation behaviour. Different forms of Cerasorb® are available: granular materials with high and low porosity optimised for specific indications as well as block forms shapeable by the surgeon for various bony defects.     

聚碳硅烷制备SiC纤维的热化学交联研究

以异丙醇锆(ZIP)为交联剂、聚碳硅烷(PCS)为先驱体,在Ar气氛的保护下通过干法纺丝、热化学交联工艺使PCS从热塑性转变热固性结构.研究了该工艺对PCS纤维质量变化、Si-H反应程度、溶解性及氧含量等性能的影响.实验结果表明:在不熔化过程中,PCS结构中的Si-H键与ZIP反应,在PCS分子间形成Si-O-Zr交联结构,随着交联温度和保温时间的升高,Si-H反应程度和纤维失重率相应提高;在测试范围内最大Si-H反应程度为73.06%,失重率2.678%,氧含量低于2.0%.     

Acid Neutralization Capacity of a Tricalcium Silicate-Containing Calcium Phosphate Cement as an Endodontic Material

A calcium phosphate cement (CPC) was shown to have the necessary attributes for endodontic materials except adequate basicity needed for antimicrobial properties. To enhance its basicity, tricalcium silicate (Ca₃SiO₅), a highly alkaline compound, was added to CPC at a mass fraction of 0.25, 0.5 or 0.75. The basicity, acid neutralization and physical properties of the CPC-Ca₃SiO₅ composites were investigated. Mineral trioxide aggregate (MTA) was used as the control. The acid neutralizing capacity of the CPC-Ca₃SiO₅ composites and MTA were measured by titrating the suspensions of ground set samples with a 0.2 mol / L HCl at predetermined pH levels, i.e., 11, 9.0, and 7.4. The setting time of CPC-Ca₃SiO₅ composites determined by the Gilmore needle method was 40 ± 10 min. Acid neutralizing capacity of CPC depended (p < 0.05) on Ca₃SiO₅ content. CPC containing 75 % Ca₃SiO₅ could neutralize slightly less acid than MTA (p < 0.05), but it had a shorter setting time than that of MTA (> 4 h) and excellent handling properties.     

Effect of Zn,Cu,Cr and Pb Chlorides on the Formation of Tricalcium Aluminate Trisulfate Hydrate

The effect of addition of Zn, Cu, Pb and Cr chlorides as admixtures on the hydration reaction of the system 3CaO·Al2O3-gypsum with molar ratio 1：3 was studied. Different ratios of each salt were used, namely 0.5%, 2% and 4% by weight of the solid mixture. Hydration reaction was carried out at 35℃ for various time intervals from 0.5 h to up to 7 d. Hydration rate of the system 3CaO·Al2O3-CaSO4·2H2O in absence and presence of different salts was studied via the determination of the combined water contents. X-ray diffraction analysis showed that the ettringite was the only hydration product formed in the different mixes. The hydration products were investigated by scanning electron microscopy （SEM） and thermal gravimetric analysis. The results indicated that the rate of formation of ettringite and its microstructure depend on the admixture and its dosage.     

电沉积磷酸钙生物陶瓷涂层的研究进展

综述了用电沉积法在金属生物材料表面沉积磷酸钙盐生物活性陶瓷工艺及工艺进展,分析了电沉积的主要控制因素,总结了该技术的特点并展望了其应用前景.     

固相反应合成磷酸四钙的物相演变

采用TGA-DSC、FTIR及XRD等方法研究了固相反应法合成磷酸四钙(TTCP) 的物相演变过程.结果表明,1200℃以上物相变化与CaO-P₂O₅-H₂O)的高温相图基本一致, 1200℃以下的物相变化为绘制CaO-P₂O₅-H₂O低温相图提供重要数据;通过揭示固相合成 TTCP物相演变的全过程,为制备出纯TTCP这一重要的磷酸钙骨水泥组成材料提供重要理 论依据.     

工业炸药热化学参数程序化计算

文章介绍使用VB程序设计语言,实现对多组分工业混合炸药的程序化计算。通过DAO（Data Access Object）对象访问.mdb数据库,动态数组存储计算变量,字符串函数等方法的使用,实现程序自动计算给定配方的爆炸反应方程式及爆炸热化学参数,通过极值计算理论求得最佳的组分配比。     

磷酸四钙合成机理及其稳定性研究

本文讨论了直接固相反应法制备磷酸四钙的工艺过程,证明原料在煅烧过程中先生成了羟基磷灰石,接着在更高的温度由羟基磷灰石分解产生磷酸四钙.同时还发现磷酸四钙在潮湿和高温环境下均会转变为羟基磷灰石.     

磷灰石陶瓷的制备、性能及其应用

本文探讨了以两种磷酸三钙为原料、采用简便的制陶工艺制成的磷灰石。研究结果表明,原料的分散细度对制品的各项性能有重要的影响。其次,选择适当的烧成温度亦是关健之一。在动物实验中,对六条狗进行了皮下、骨膜下及骨内种植实验,所得结论认为磷灰石是一种生物可容性种植材料,促进骨质生长和新骨形成。在动物实验的基础上对30名重症牙周炎患者作植入手术,并与单纯采用翻瓣手术的作了比较,结果表明,磷灰石植入手术显然比单纯牙龈翻瓣手术优越。     

木质包装废弃物热化学反应转化特性研究

采用热重红外联用分析和热解气质联用分析技术,考察了红橡木材包装废弃物的热分解、气相组分生成及分布规律。研究表明:在800℃终温和10℃/min的升温速率条件下,红橡木材包装废弃物的主要热解阶段集中在220～385℃,失重率为78.99%;高温区热解活化能明显低于低温区,说明随着温度的升高较容易发生热解反应;热解初期主要是水分和部分酸类、醛类物质的析出,主要热解阶段为H2O,CO2,CO,CH4和酸类、醛类、酯类等的大量析出,在热解后期主要为CO2和CH4的析出;热解析出的气体主要为含氧官能团的有机化合物,包括酸类(19.29%)、醛类(15.14%)、酯类(9.97%)、酮类(9.00%)、糖类(8.59%)、酚类(5.29%)、醇类(3.63%)等。     

A Facile Synthesis of Cerium Phosphate Nanofiber by Solution-solid Method

A solution-solid method is developed to construct cerium phosphate (CePO₄) nanofibers. Tetraphosphoric acid formed the condensed linear polyphosphate (PnO_3n+1)^(n+2)-before reacting with cerium carbonate (Ce₂(CO₃)₃) powder, which was favourable for one dimensional CePO₄ nanofibers forming. The growth mechanism was proposed based on solution-solid process. CePO₄ nanofibers display strong UV luminescence emission and weak blue emission.     

微波辅助溶剂热法制备磷酸钙微球和多面体

磷酸钙材料具有良好的生物相容性, 被广泛应用于生物材料领域。本研究以Ca(CH₃COO)2、NaH₂PO₄?2H₂O和双亲嵌段共聚物PLA-mPEG为原料, 通过微波辅助120℃水热反应30 min, 合成了自组装结构磷酸钙微球。以相同的反应原料, 在水和乙二醇混合溶剂中, 通过微波辅助120℃溶剂热反应30 min, 制备了具有多面体结构的磷酸钙。通过X射线粉末衍射(XRD)、透射电子显微镜(TEM)、扫描电子显微镜(SEM)和热重分析(TG)对所制备样品的物相和形貌进行了表征。研究发现乙二醇的加入对磷酸钙的结构和形貌具有显著的影响。以牛血红蛋白为模型, 研究了所制备的两种不同磷酸钙材料的蛋白吸附效果。磷酸钙材料的牛血红蛋白吸附量随装载溶液中牛血红蛋白浓度的增加而增大, 随样品制备过程中的乙二醇加入量的增加而减小。     

料浆法磷铵生产工艺发展与五大磷肥工程改造

针对引进磷酸浓缩工艺生产磷铵的技术不适应我国矿产资源具体情况的难题，开发了料浆法磷铵生产工艺技术，已在21个省区布点推广建设了87套装置，形成生产能力279×104 t/a的规模，占全国磷铵生产能力的60%。最近在贵州瓮福实施料浆法磷铵与引进的传统磷酸浓缩工艺联产的成功，为五大磷肥工程的改造提供了一条新的途径。     

过渡金属磷酸盐空旷骨架化合物合成研究

空旷骨架结构过渡金属磷酸盐是一种重要的无机多功能材料,近年来,这一类化合物晶体的合成研究引起了人们的广泛兴趣.主要介绍了该类化合物的研究现状与发展历史,并讨论了该类材料的发展前景.     

一种笼状膨胀型磷酸盐的合成

试验采用正交法,利用磷酸、季戊四醇、三聚氰胺合成一种膨胀型磷酸盐,由膨胀度和剩碳率作为衡量膨胀性阻燃剂的主要检测手段,实验发现:磷酸、季戊四醇和三聚氰胺摩尔比为3∶1∶1,磷酸和季戊四醇反应时间为1h,反应温度130℃,所得磷酸酯与三聚氰胺反应温度为180℃,时间4h,阻燃效果佳,从红外光谱确定了笼状结构的存在.     

A simple sol-gel technique for synthesis of nanostructured hydroxyapatite, tricalcium phosphate and biphasic powders

Hydroxyapatite (HAP), β-tricalcium phosphate (β-TCP) and biphasic calcium phosphate (BCP) nanocrystalline powders were prepared by a simple sol-gel approach. Because of the unique characteristic of the phosphorous source ((CH₃O)₃P) and the proper uses of calcic and phosphorous sources with Ca/P molar ratio between 1.4 and 1.67, three different kinds of nanostructured calcium phosphate powders were achieved by changing the ratio of calcic and phosphorous sources. For HAP and β-TCP, pure phases were prepared. For BCP, the proportion of HAP and β-TCP could be changed by thermal treatment.     

片层纳米结构磷酸铁制备及对磷酸铁锂电性能的影响

采用液相反应结晶法,在磷源及铁源中添加NaAlO_2,利用在结晶过程中生成的Al(OH)3胶体对结晶面的作用,合成出具有片层纳米结构纺锤体状磷酸铁前驱体,并通过高温固相法进一步制备成磷酸铁锂。采用XRD、FT-IR、SEM、TEM、比表面及孔隙率分析、激光粒度分析和电化学性能测试等手段对样品进行表征分析。结果表明,由具有片层纳米结构的磷酸铁前驱体制备的磷酸铁锂比由无片层纳米结构的磷酸铁前驱体制备的磷酸铁锂在0.1C下的首次放电容量提升了20%,达到151.48mAh/g,电极电荷转移电阻降低了约75%,仅为27.23Ω;0.1C倍率下循环50次后容量保持率可达96%。同时,对Al(OH)3胶体影响片层纳米结构磷酸铁生成机制进行了分析和讨论。