铁纳米颗粒的热行为及热稳定性

采用梯级加热的方法对铁纳米颗粒进行了处理。根据透射电镜(TEM)和X射线衍射(XRD)的表征结果,在时间上反演了铁纳米颗粒的被加热过程,同时对铁纳米颗粒的热行为和热稳定性进行了分析。研究结果表明,实验所用的铁纳米颗粒具有突变型的氧化行为特征,其在大气中的氧化转变临界温度在523K左右,此温度以下该种铁纳米颗粒能够保持成分及性质稳定,可以安全使用。     

纳米二氧化硅的制备及应用

以Na2SiO3.9H2O为原料,浓H2SO4为酸试剂,采用化学沉淀法制备纳米二氧化硅,讨论Na2SiO3浓度、搅拌速度、pH值、分散剂Na2SO4和表面活性剂聚乙二醇等因素对产物特性的影响,并用红外光谱、透射电镜、扫描电镜和X射线衍射等分析手段对二氧化硅纳米颗粒进行结构和形貌表征。利用本体聚合法制备了聚甲基丙烯酸甲酯-纳米二氧化硅复合材料,研究纳米二氧化硅颗粒对聚甲基丙烯酸甲酯材料力学性能的增强作用以及透光度的影响。结果表明:二氧化硅纳米粒子呈球形,粒径在50~100 nm范围内、分布均匀、呈无定形;填充纳米二氧化硅的复合材料的冲击强度和弯曲强度明显提高。     

CdS纳米复合粒子的制备和光催化性能研究

为获得颗粒尺寸、形貌等比较规则的纳米CdS颗粒,通过逐层自组装技术和"两步法"相结合的方法在介孔分子筛SBA-15孔道内制备CdS纳米粒子,首先应用带电聚合物聚二烯丙基二甲基氯化铵(PDDA)、聚苯乙烯磺酸钠(PSS)将SBA-15孔道表面功能化,然后引入CdS前驱体Cd(CH3COO)2.2H2O,再将产物在H2S气氛中硫化得到最终产物SBA-15-PDDA-PSS-CdS。采用X射线衍射、N2吸附-脱附等手段进行测试表征,并将所制样品用于降解甲基橙来测试其光催化性能。结果表明:所制得的纳米CdS颗粒较小,分布均匀;纳米CdS在紫外光下对甲基橙具有良好的降解能力。     

含离子液体介质中铜纳米粒子的制备及其影响因素

在含有离子液体[BMIm]PF6、[PMIm]PF6和[C6MIm]PF6的介质中,通过还原Cu2+制备铜纳米粒子.通过TEM和XRD分析,对比研究了Cu2+浓度、还原剂种类以及离子液体[BMIm]PF6、[PMIm]PF6和[C6MIm]PF6对所制备的铜纳米粒子的粒径和形貌的影响.结果表明:Cu2+浓度对铜纳米粒子的粒径和形貌没有明显的影响;离子液体的类型对铜纳米粒子的粒径也没有明显的影响,但对形貌有一定的影响;还原剂对铜纳米粒子的粒径及形貌影响较大.     

纳米SiO_2的分散对大豆蛋白/PVA复合膜性能的影响

采用超声波对纳米SiO2进行分散,为探讨纳米SiO2的分散情况对大豆蛋白/PVA复合薄膜性能的影响,通过单因素试验和正交试验,对复合薄膜的性能进行了系统研究。试验结果表明:纳米SiO2的超声时间,超声温度和超声功率对复合薄膜的性能均有影响;当超声温度为45℃,超声功率为160W,超声时间为40min时得到的复合膜性能最佳,其中超声温度对薄膜的性能影响最大,其次是超声功率和超声时间;在最佳条件下,薄膜的抗张强度为9.33MPa,伸长率为76.13%,透光率为21.85%,吸水率为47.77%。     

Synthesis of nanosized gadolinium doped ceria solid solution by high energy ball milling

This paper reports the development of a new process for the synthesis of gadolinium-doped ceria (20GDC) solid solution nanoparticles, as a solid electrolyte for use in solid oxide fuel cells. It is based on high energy milling (mechanical alloying or MA) of CeO₂ and Gd₂O₃ powders containing 10 mol% Gd₂O₃. The samples, obtained after different milling times of 10 to 60 h, were characterized by X-ray diffraction (XRD), BET method of the specific surface area measurement, electron microscopy and Raman spectroscopy. The fluorite-structured Ce_0.8Gd_0.2O_1.9 solid solution nanopowder with the surface area of 16.86 m²/g and particle sizes below 50 nm was obtained by milling the oxide mixture for 30 h. Increase in the milling time beyond 30 h led to the smaller crystallite sizes and more agglomeration. The structural changes, as evidence for the formation of solid solution, which occurred during the course of the milling process, could be appropriately followed and discussed by Raman spectroscopy.     

溶胶-凝胶法制备纳米润滑材料

溶胶-凝胶法是近年来开发的一种制备纳米润滑材料的新方法。溶胶-凝胶法制备出的纳米颗粒粒径小、均匀度高。简述了溶胶-凝胶法制备纳米润滑颗粒的方法和流程。     

贵金属纳米粒子的常见合成方法及应用

贵金属纳米材料在基础研究和实际应用领域具有巨大价值而受到广泛重视。由于该类材料具有尺寸小,比表面积大等特性,而表现出很强的催化活性。介绍了贵金属纳米材料制备方法,讨论了贵金属纳米材料发展的优势和存在的缺陷与不足,并对今后的研究方向提出了建议。     

金属氧化物纳米复合催化剂的研究进展

介绍了几种重要的过渡金属纳米氧化物催化剂,通过控制反应条件、改变表面活性剂的添加比例、选择不同反应途径等不同制备方法,制备出具有不同晶型（面）、不同粒径大小、具有良好吸附性能、化学性质稳定、可循环利用的催化活性高的氧化物催化剂。通过实验研究发现,晶型（面）、粒径大小及形状是影响纳米催化剂性能的关键因素,同时探讨了氧化物催化反应机理,以期针对不同的化学反应体系设计、研发出特定粒径大小、形状、高活性晶型（面）的高催化效率、低成本的纳米催化剂,为氧化物催化剂的开发应用提供一定的参考。     

Preparation and characterization of SLNs (W/O/W type) contained lipoic acid PEG ester by variation lipid

This study describes a nanoparticle preparation method using SLNs (solid lipid nanoparticles: W/O/W type). Classical methods have high encapsulation efficiency for hydrophobic drugs but have low encapsulation efficiency (2–3%) for hydrophilic drugs. The preparation of SLNs that has a far higher skin penetration effect compared with general liposomes is proposed in this study. An additional aim is to also maximally increase encapsulation efficiency of hydrophilic drugs. The SLNs preparation method described here used coconut oil, jojoba oil and macadamia oil that are resistant to degradation by microorganisms and are usable emulsifiers due to their physical properties imparted by their fatty acid composition. The results indicate that SLNs containing coconut oil had the highest encapsulation efficiency and also the smallest average particle size (270 nm). The largest particle size was produced by macadamia oil and 1% Tween 60. The fastest release of contents resulted from SLNs made of coconut oil and 2% Tween 60, while the slowest release was from SLNs made of macadamia oil and 2% Tween 20.