Ⅲ-V族半导体纳米材料的制备与尺寸控制

论述了Ⅲ-V族半导体纳米材料的制备与尺寸控制,其制备法分为物理法和化学法。物理法包括离子注入法、溅射法和激光烧蚀法,化学法包括高温有机液相合成法、有机溶剂热法、水热法和溶胶-凝胶法等。其中高温有机液相合成法较易制备尺寸均一、稳定的半导体纳米晶,有机溶剂热法、水热法和溶胶-凝胶法设备简单、反应条件温和,具有广阔的应用前景。     

纳米氧化铜制备方法的研究进展

氧化铜(CuO)是二元过渡金属氧化物,其纳米结构单元有序自组装的复杂几何结构研究是近年来材料研究的热点。CuO纳米材料的多种创新研究主要是针对其制备方法,迄今为止已开发了一系列的制备方法,各种方法制备出不同结构的CuO纳米材料以适用于多方面的应用需求。本文分别对纳米氧化铜的固相合成法、液相合成法、电化学合成法、溶剂燃烧合成法以及配位沉积法这五种制备方法的研究进展做了分析总结和概述。     

Ⅲ-Ⅴ族半导体纳米材料的制备与尺寸控制

论述了Ⅲ-Ⅴ族半导体纳米材料的制备与尺寸控制,其制备法分为物理法和化学法.物理法包括离子注入法、溅射法和激光烧蚀法,化学法包括高温有机液相合成法、有机溶剂热法、水热法和溶胶-凝胶法等.其中高温有机液相合成法较易制备尺寸均一、稳定的半导体纳米晶,有机溶剂热法、水热法和溶胶-凝胶法设备简单、反应条件温和,具有广阔的应用前景.     

锂离子电池正极材料磷酸铁锂的研究进展

对锂离子电池正极材料磷酸铁锂的制备方法进行了介绍。首先介绍了固相合成法的基本过程、研究改进情况以及优缺点,其次介绍了液相合成法即水热法、溶胶-凝胶法和共沉淀法的基本原理及研究进展,然后从非晶相掺杂和晶相掺杂两个方面对锂离子电池材料的性能改进研究情况进行了介绍,最后对材料的发展方向进行了展望。     

银纳米线的制备及应用研究进展

银纳米线由于其优异的导电性和良好的延展性,被广泛研究并应用于制备透明导电薄膜。对银纳米线的制备方法进行总结,包括模板法和液相合成法,分析对比了两种方法的优缺点,并对目前研究较多的液相合成法中涉及的表面活性剂、成核缓释剂的作用作了详细阐述,为银纳米线的可控合成提供了参考。银纳米线作为最有可能替代传统ITO透明电极的材料,相关研究表明银纳米线的长度、直径对透明电极的性能有很大的影响,为后续优化银纳米线的制备指明了方向。     

纳米远红外陶瓷粉体的制备工艺与性能研究

本研究分别采用固相合成法和液相共沉淀法制备远红外陶瓷粉体，采用X光小角散射法测试其颗粒分布和平均粒度，采用XRD分析其物相和SEM观察其显微结构形貌，结果表明，液相共沉淀法制备的远红外陶瓷粉体的平均粒度达到95纳米，且颗粒大小分布窄，而固相合成法制备的远红外陶瓷粉体颗粒粗大且不均匀，经中国计量科学研究院测试，液相共沉淀法制备的远红外陶瓷粉体的法向全辐射发射率为93％，固相合成法制备的远红外陶瓷粉体的法向全辐射发射率仅为82％。     

模板法在纳米羟基磷灰石制备中的应用进展

由于模板法可以有效地设计和调控纳米材料的形貌、结构、尺寸等,赋予纳米材料独特的性能,近年来,在介孔纳米羟基磷灰石的制备研究中,引起了学者们的广泛关注。简述了软模板法和硬模板法合成纳米羟基磷灰石的机理,重点综述了模板法在制备纳米羟基磷灰石中常用的模板剂类型,并总结了其优缺点,最后对模板法合成纳米羟基磷灰石进行了展望。     

模拟体液法制备纳米级羟基磷灰石

以制备羟基磷灰石粉体的其中一种反应体系为研究对象,用模拟体液法制备纳米羟基磷灰石粉体。在此实验过程中,研究了反应温度、反应浓度和反应时间对羟基磷灰石粉体合成的影响。结果发现,制备纳米级羟基磷灰石的最佳工艺条件为:反应温度为60℃,浓度为15SBF,反应时间为10h。在此工艺条件下,制备的羟基磷灰石粉体的微观形貌为球形颗粒,平均颗粒直径为30nm。     

配合法制备InNbO_4及其光催化活性的研究

以配合法制备InNbO4催化剂,研究了在甲醇为电子给体,Pt为助催化剂的条件下,InNbO4光催化分解水的产氢活性。并与固相合成法制备的InNbO4光催化活性进行对比。通过X-射线衍射和比表面分析对两种方法制备的催化剂进行表征。研究发现,在焙烧温度为900℃、时间为12 h时,配合法制备的InNbO4光催化产氢活性最高(87.27μmol),为固相合成法的2倍。     

低温敏感示温材料的研究

研究了六水合氯化钴与六次甲基四胺通过低热固相反应制备钴(Ⅱ)—六次甲基四胺配合物,利用元素分析法和XRD分析法进行表征,并与液相合成法进行了比较,还研究了影响该产物示温变色性能的因素。     

超细碳酸钡粉体制备方法的研究进展及展望

综述了超细碳酸钡粉体制备方面的研究进展。详细介绍了超重力法、液相沉淀法、微乳液法、均相沉淀法、模板法、低温固相合成法、微波辅助合成法等不同方法在超细碳酸钡制备中的应用与研究,对各种方法的优缺点作了具体的讨论和分析,并提出了超细碳酸钡粉体制备方法的发展方向。     

New hydroxyapatite–hydrotalcite composites I. synthesis

The synthesis and characterization of original materials, composed by hydrotalcite and hydroxyapatite, is discussed. All the syntheses were carried out in presence of microwave irradiation during the crystallization step. The interactions between the two compounds depend on the synthesis procedure. If hydroxyapatite is incorporated to hydrotalcite, the first compound is encapsulated by hydrotalcite. Instead, if hydroxyapatite is first prepared, the resulting solid is essentially a hydrotalcite with interlayered hydroxyapatite. When the composite material is synthesized by a simultaneous coprecipitation, the small clusters of hydroxyapatite and hydrotalcite are homogeneously dispersed. Consequently, the specific surface area and the particle size vary.     

Simple and Rapid Synthesis of Magnetite/Hydroxyapatite Composites for Hyperthermia Treatments via a Mechanochemical Route

This paper presents a simple method for the rapid synthesis of magnetite/hydroxyapatite composite particles. In this method, superparamagnetic magnetite nanoparticles are first synthesized by coprecipitation using ferrous chloride and ferric chloride. Immediately following the synthesis, carbonate-substituted (B-type) hydroxyapatite particles are mechanochemically synthesized by wet milling dicalcium phosphate dihydrate and calcium carbonate in a dispersed suspension of magnetite nanoparticles, during which the magnetite nanoparticles are incorporated into the hydroxyapatite matrix. We observed that the resultant magnetite/hydroxyapatite composites possessed a homogeneous dispersion of magnetite nanoparticles, characterized by an absence of large aggregates. When this material was subjected to an alternating magnetic field, the heat generated increased with increasing magnetite concentration. For a magnetite concentration of 30 mass%, a temperature increase greater than 20 K was achieved in less than 50 s. These results suggest that our composites exhibit good hyperthermia properties and are promising candidates for hyperthermia treatments.     

SiC-Al2O3系复合耐火粉体的合成

以蜡石和天然石墨为原料,通过碳热还原法合成了SiC-Al2O3系复合耐火粉体.考察了加热温度对SiC-Al2O3系复合耐火粉体合成的影响并对合成过程进行了热力学分析.结果表明:加热温度对于SiC-Al2O3系耐火粉体的合成具有重要影响.通过在蜡石中添加适量的天然石墨,并将蜡石和石墨的混合物在氩气中经1 650 ℃以上温度热处理4 h,可以合成SiC-Al2O3耐火粉体.合成的SiC-Al2O3耐火粉体为超微粉,其平均颗粒粒径为2.277 μm.     

离子液体中超细银的绿色制备

采用两步合成法合成了1-丁基-3-甲基咪唑四氟硼酸盐([bmim]BF4)的离子液体,并用IR、1HNMR对其进行了表征。在离子液体中,加入对苯二酚和用少量无水乙醇溶解的硝酸银,成功制备了超细银。用XRD、SEM、IR和TEM对产物进行了表征。结果表明,采用离子液体方法可以制备出超细银,银粒径较小且分散均匀,不易团聚。结果表明,离子液体既起到溶剂作用,又起到分散剂的作用,是超细银绿色制备的良好介质。     

直接沉淀法超细粉体氧化镁的制备与表征

研究了以硼镁矿生产的工业硫酸镁和草酸铵为起始原料,采用直接沉淀法合成超细粉体氧化镁的简单方法。考察了反应物浓度、加料方式和煅烧温度等因素对粉体质量的影响,初步探索到较好的工艺条件,550℃为最佳煅烧温度。采用红外光谱(IR),热重分析(TG-DTA),X射线粉末衍射(XRD),透射电镜(TEM)等对该纳米微粒的结构进行了表征。结果表明,所制得的纳米氧化镁微粒呈立方晶格,形貌为椭球体,分散性好,粒径在25～35 nm之间。直接沉淀法合成超细粉体氧化镁操作简单,原料易得,生产成本低,产品纯度高,是一种易于工业化的合成方法。     

燃烧合成钛酸钡粉体的研究进展

近年来，高纯超细钛酸钡粉体的制备技术发展十分迅速，它们在钛酸钡电子陶瓷的应用研究中起着日益重要的作用。燃烧法制备陶瓷粉体是一种新型的材料合成工艺技术，有其独特的优点和特点。简要回顾了燃烧法合成的历史，对燃烧法合成无机粉体现有工艺做了新的分类和介绍，最后就燃烧合成钛酸钡粉体的制备技术做了综述。     

羟基磷灰石生物陶瓷的研究状况及发展趋势

综合论述了羟基磷灰石生物陶瓷的研究状况、分类、特性以及主要合成方法。同时，综合探讨了羟基磷灰石生物陶瓷临床应用中存在的问题及目前解决问题的途径和未来的发展趋势。     

Inclusion of carbon nanotubes in a hydroxyapatite sol–gel matrix

In this study, the inclusion of multi-walled carbon nanotubes as the second phase in the hydroxyapatite matrix, in order to improve the mechanical strength, has been performed via the sol–gel process. The stability of carbon nanotube sol with the changes of pH and dispersant values (sodium dodecyl sulfate) was evaluated by zeta potential analysis. The results indicated that synthesis of hydroxyapatite particles in the presence of the carbon nanotubes had the best result in homogenization of the carbon nanotube dispersion and faster crystallization of hydroxyapatite. The crystallization of hydroxyapatite phase was investigated with differential scanning calorimetry (DSC) and X-ray diffraction and the microstructure of the obtained composite powder was studied by electron microscopy.     

Nanosize hydroxyapatite: doping with various ions

Abstract

Abstract

Natural crystal sizes of bone minerals are present in the nanoscale regime (specifically less than 100 nm in at least one direction). Therefore, research on the synthesis and characterisation of nanosize hydroxyapatite has gained significant importance in numerous biomedical applications. This is because currently used pure micrometre sized hydroxyapatite has poor mechanical properties, which limits it use in non-load bearing applications. For these reasons, various ions could be easily substituted into nanostructured hydroxyapatite to alter its biocompatibility, sinterability and mechanical properties. In this study, the synthesis methods, biocompatibility, physical, microstructural and nanostructural characteristics of nanocrystalline hydroxyapatite are reviewed. Compared to pure micrometre structured hydroxyapatite, numerous properties (most notably, biocompatibility properties pertinent for orthopedic applications) are improved for nanostructured hydroxyapatite doped with various ions. Such studies demonstrated that the mechanical properties and phase stability of nanohydroxyapatite doped with various ions after sintering at high temperatures should be investigated in more detail.