纳米氧化镍纤维的制备及表征

利用静电纺丝法,制备出聚乙烯吡咯烷酮(PVP)/四水乙酸镍纤维前躯体,通过焙烧前躯体制备出纳米氧化镍纤维,并用透射电子显微镜(TEM),扫描电子显微镜(SEM),X-射线衍射(XRD)以及热重分析(TG)对纤维进行了表征.     

纳米Ni/SiO_2核壳结构粒子的制备和表征

采用微波多元醇法制备了纳米Ni粒子,再通过水解正硅酸乙酯(TEOS)得到SiO2,实现对纳米Ni粒子的表面包覆,形成Ni/SiO2核壳结构。通过X射线衍射和透射电镜对包覆前后的粒子进行了观察分析。结果表明,微波多元醇法制备的Ni纳米粒子平均粒径100 nm,分散较均匀;包覆后的Ni粒子表面有一层非晶态的SiO2壳层,壳层的厚度随TEOS的浓度增大而增加。     

Hydrothermal synthesis and photoluminescence behavior of CeO2 nanowires with the aid of surfactant PVP

Well-crystalline CeO_2 nanowires were prepared via a surfactant-assisted hydrothermal process.Reaction temperature and reaction time were changed for the determination of optimal synthesis parameters.The as-obtained products were characterized by X-ray diffraction (XRD),high-resolution transmission electron microscopy(HRTEM),and field emission scanning electron microscopy(FESEM).The results show that single crystal CeO_2 nanowires with high yield and good uniformity can be obtained hydrothermally at 180℃...     

聚乙烯吡咯烷酮对酸诱导液相沉积体系中GeO_2颗粒形貌的影响

在室温下,通过酸诱导液相沉积的方法,制备出了二氧化锗(GeO2)颗粒。制得的GeO2颗粒通过扫描电子显微镜(SEM),透射电子显微镜(TEM)和X射线衍射(XRD)进行表征。实验结果表明,向前驱液中加入酸,可以诱导锗酸根离子转化成立方体型的GeO2颗粒析出。而向反应液中再加入少量的聚乙烯吡咯烷酮(PVP)后,会析出纺锤体型的GeO2晶体颗粒。     

溶胶沉淀法合成修饰氧化铕溶胶与特性表征

以噻吩甲酰三氟丙酮（TTA）、1,10-邻菲罗啉（phen）作为修饰剂,采用溶胶沉淀法制备得到修饰纳米氧化铕甲醇溶胶。采用荧光光谱、紫外可见光谱（UV-Vis）和高分辨率透射电镜（HRTEM）等方法研究了NaOH浓度对修饰氧化铕有机溶胶荧光特性的影响和修饰氧化物纳米粒子的结构及性能。结果表明,用phen和TTA作为修饰剂得到的修饰氧化铕溶胶都能发出了Eu^3＋的特征红色荧光,NaOH浓度对修饰纳米氧化铕甲醇溶胶的荧光强度具有很大的影响;HRTEM和选区衍射实验表面纳米粒子的核心为氧化铕微晶,其平均粒径小于10nm。由于修饰氧化铕溶胶能发出很强的红色荧光,是一种潜在的优质发光材料。     

燕窝状TiO_2纳米构筑体的制备及其光催化性能

以Ti(SO4)2·2H2O为主要反应物,在雪碧(碳酸饮料)介质中通过水热法制得燕窝状构筑体的锐钛矿型TiO2。运用透射电子显微镜(TEM)、扫描电子显微镜(SEM)、X射线衍射分析仪(XRD)等表征手段证实,此组装结构受雪碧中的蔗糖、柠檬酸等成分及PVP含量控制,并阐明其形成过程。制得的燕窝状TiO2显示出较好的光催化性能。     

微乳液体系中介孔硫化镉纳米颗粒的制备

以氯化镉、硫代乙酰胺为原料在水包油(O/W)型微乳液体系中原位合成硫化镉半导体纳米粒子。采用粉末X-射线衍射(XRD)、高分辨透射电镜(HRTEM)、扫描电子显微镜(SEM)和X-射线光电子能谱仪(XPS)对制备的硫化镉纳米颗粒进行表征。结果表明制备的硫化镉是纯的球形介孔硫化镉纳米颗粒,粒径约为75nm。     

Controlled synthesis and magnetic properties of Fe<Subscript>3</Subscript>O<Subscript>4</Subscript> walnut spherical particles and octahedral microcrystals

Magnetite Fe₃O₄ walnut spherical particles and octahedral microcrystals were successfully synthesized from K₄ [Fe (CN)₆], K₃ [Fe (CN)₆] and NaOH reagents via a simple hydrothermal process. And the uniform morphology of octahedral microcrystals was obtained in the presence of ethylene glycol. The morphology and structure of products were characterized by powder X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The results showed that the Fe₃O₄ walnut spherical particles and octahedral microcrystals were single crystals with the face-center cubic structure and with size distributions from 2.2 to 8.6 μm and 1.6 to 12.5 μm, respectively. Their magnetic properties were detected by a vibrating sample magnetometer at room temperature. The walnut spherical particles exhibited a ferromagnetic behavior with the coercive force (Hc), saturation magnetization (Ms) and remanent magnetization (Mr) being 150.57 Oe, 97.634 and 12.05 emu/g, respectively. For the octahedral microcrystals they were 75.28 Oe, 101.90 and 6.69 emu/g, respectively. Different sizes of walnut spherical particles were controlled synthesized through adjusting the NaOH concentration. It was found that ethylene glycol molecules have a significant effect on the formation of Fe₃O₄ octahedra. A possible mechanism was also proposed to account for the growth of these Fe₃O₄ products. Supported by Fund of weinan Teachers University (Grant No. 08YKZ008), the National Natural Science Foundation of China (Grant No. 20573072) and Doctoral Fund of Ministry of Education of China (Grant No. 20060718010)     

液相合成不同形貌的Cu_2O微晶

以乙酸铜为铜源,L-抗坏血酸为还原剂,采用简单的液相反应制备不同形貌的Cu2O微晶,并进行了表征。考察了温度、反应物浓度、表面活性剂种类等条件对Cu2O微晶粒径及形貌的影响,初步探讨了Cu2O微晶的生长机理。实验结果表明:通过改变表面活性剂的种类,可以选择性地制备出不同形貌的Cu2O微晶。以PVP为表面活性剂时制备的是直径约为1μm的Cu2O微球,以PEG为表面活性剂时制备的是边长约为700 nm的Cu2O立方体。     

Surface modification of Fe_3O_4 nanoparticles and their magnetic properties

Fe3O4 magnetic nanoparticles were synthesized by the hydrothermal method,and the influences of the surfactant sodium bis(2-ethylhexyl) sulfosuccinate (AOT) on the particles were investigated. The structure,morphology,and magnetic properties of the products were characterized by X-ray powder diffraction (XRD),transmission electron microscopy (TEM),Fourier transform infra-red spectroscopy (FT-IR),and vibrating sample magnetometer (VSM). It is confirmed that the as-prepared nanoparticles have been modified by ...     

Facile route to prepare TaC,NbC and WC nanoparticles

By a novel solid-state reaction process using amorphous C3N4 （α-C3N4） and transition metal oxides as starting reagents, cubic TaC, NbC and hexagonal WC nanoparticles were successfully synthesized at 1150 . The products were characterized by power X-ray diffraction （XRD）, field-emission scanning electron microscope （FE-SEM）, energy-dispersive X-ray spectroscopy （EDX） transmission electron microscopy （TEM） and high-resolution TEM （HRTEM）. The experimental results show that a-C3N4 obtained by the reaction between C3N3C13 and Li3N is a highly efficient carburation reagent and the transition metal oxides are completely transformed into the corresponding metal carbide nanoparticles at 1150 ℃, respectively, which is significantly lower than that reported for the traditional preparation of carbides, typically〉 1600 ℃. The TaC, NbC and WC nanoparticles are found to have an average particle size of 10 nm, 15 nm and 8 nm by TEM observation, respectively.     

ZnFe_2O_4纳米粒子的制备及其磁性能

以乙酰丙酮铁和乙酰丙酮锌为原料、三甘醇为溶剂,采用一步法制备ZnFe2O4纳米粒子。通过透射电子显微镜(TEM)、X-射线粉末衍射仪(XRD)和磁性能测量系统(MPMS)等表征手段对ZnFe2O4纳米粒子进行了表征。结果表明,所制备的ZnFe2O4纳米粒子平均粒径约为6 nm,尺寸均匀,水溶性良好,在室温条件下呈现超顺磁性。     

用大洋锰结核直接制备铁氧体的研究

大洋锰结核进行预处理后,分别与质量分数为0、10%、15%及20%的NaOH助熔剂混合,在1 000 ℃下煅烧5 h,合成软磁铁氧体材料.产物的磁化率随助熔剂的质量分数的增加而升高,当助熔剂的质量分数超过15% 时样品的磁化率明显降低. X射线衍射(XRD)和扫描电镜(SEM)表明,锻烧所得的软磁性材料为具有尖晶石结构的铁酸锰,助熔剂可以抑制方锰矿的形成,提高铁酸锰的产率.能量分散谱仪（EDS）显示产物中有大量的锰、铁元素,其比值接近于3∶1.磁滞回线和磁化率分析数据说明,合成的铁酸锰具有良好的磁化率和易饱和磁化性.     

ZnO/PVP纳米复合膜的光学特性

采用高分子网络原位合成法制备了ZnO/PVP纳米复合膜.并且通过多种测试手段对ZnO/PVP纳米复合膜的光学特性进行了分析.通过XRD,TEM的测试结果可知,以聚乙烯吡咯烷酮(PVP)为模板,原位合成ZnO纳米粒子,具有六角纤锌矿结构;分散性好,粒径分布窄等特点;从光致发光谱中可以看出由于PVP的引入,使得ZnO纳米粒...     

CuO-containing multi-wailed carbon nanotubes: a novel catalyst for the catalytic ozonation of humic acid in water

CuO particles were attempted to fill in the channel of multi-walled carbon nanotubes(MWCNTs)as novel catalytic materials CuO@MWCNTs used for ozonation of humic acids(HA)in aqueous solution.Catalyst samples were characterized by transmission electron microscopy(TEM),X-ray diffraction(XRD),thermogravimetric analysis(TG)and X-ray photoelectron spectroscopy(XPS).The removal efficiency of HA was promoted in the presence of CuO@MWCNTs compared with that of Al2 O3-supported CuO catalyst(CuO/Al2O3)and CuO-coating MWCNTs catalyst(CuO/MWCNTs).The strong synergetic effect in the confinement environment on CuO nanoparticles can attribute to the locally higher pressure due to the lower potential energy of reactants in the channels.Strong interaction happened between the catalyst and reactants,which promoted the decomposition of ozone and the generation of OH.The results of experimental and theoretical investigation confirmed that CuO@MWCNTs promotes the initiation and generation of OH,hence accelerating the degradation of organic pollutants.     

CuO-containing multi-walled carbon nanotubes:a novel catalyst for the catalytic ozonation of humic acid in water

CuO particles were attempted to fill in the channel of multi-walled carbon nanotubes (MWCNTs) as novel catalytic materials CuO@MWCNTs used for ozonation of humic acids (HA) in aqueous solution.Catalyst samples were characterized by transmission electron microscopy (TEM),X-ray diffraction (XRD),thermogravimetric analysis (TG) and X-ray photoelectron spectroscopy (XPS).The removal efficiency of HA was promoted in the presence of CuO@MWCNTs compared with that of Al2O3-supported CuO catalyst (CuO/Al2O3) and CuO-coating MWCNTs catalyst (CuO/MWCNTs).The strong synergetic effect in the confinement environment on CuO nanoparticles can attribute to the locally higher pressure due to the lower potential energy of reactants in the channels.Strong interaction happened between the catalyst and reactants,which promoted the decomposition of ozone and the generation of OH.The results of experimental and theoretical investigation confirmed that CuO@MWCNTs promotes the initiation and generation of OH,hence accelerating the degradation of organic pollutants.     

Mechanical Properties and Wettability of Bagasse-reinforced Composite

Bagasse fibers were modified using NaOH, KH550, and NaOH/KH550, respectively, and used as reinforcement to prepare bagasse/starch/PVA composite. A combination of Fourier-transform infrared(FTIR) spectroscopy and X-ray diffraction(XRD) was used to investigate the chemical composition. The surface of bagasse fibers and cross-sectional morphologies for bagasse/starch/PVA composite were also characterized by scanning electron microscopy(SEM). Contact angles were measured to test the wettability of the resulting composite. After the chemical treatment with NaOH/KH550, the mechanical properties of the composite can be greatly improved. The contact angle is larger, indicating the variation of surface property from hydrophilicity into hydrophobicity.     

超细镍粉化学气相法制备过程中温度的影响

以NiCl2·6H2O为原料,采用化学气相沉积法制备超细镍粉,就反应温度对产物形貌、粒度等性能的影响进行了详细考察。采用扫描电镜、激光粒度分析、X射线衍射对样品的形貌、粒度、物相等进行了表征。结果表明:温度对颗粒的结晶度和粒径分布有显著影响,采用化学气相沉积法制备的粉末颗粒为纯镍粉,形貌基本为类球形,粒度在亚微米级范围内,结晶度良好。     

类球状和棒状Eu_2O_3和Sm_2O_3纳米粒子的合成与表征

采用表面活性剂和超声波辅助的沉淀法合成了类球状和棒状多晶Eu2O3和Sm2O3纳米粒子,并用透射电镜(TEM)、选区电子衍射(SAED)、X射线衍射(XRD)、N2吸附-脱附和紫外-可见漫反射(UV-Vis DRS)技术表征了其物理性质.结果表明,以十二烷基硫酸钠作表面活性剂所得产物为类球状体心立方晶相Eu2O3和单斜晶相Sm2O3纳米粒子,比表面积为44~49 m2/g;而以聚乙烯吡咯烷酮作表面活性剂所得产物则是棒状正交晶相Eu2O3和体心立方晶相Sm2O3纳米粒子,比表面积为34~37 m2/g.除了在紫外光区(λ390 nm)有较强的吸收外,类球状和棒状Eu2O3和Sm2O3纳米粒子在可见光区(390 nmλ535 nm)也有不同程度的吸收.该吸光性能差异与所得稀土氧化物的表面形貌和晶体结构有关.     

微波合成PrF3空心纳米粒子和氢氧化镨纳米棒

用快速高效的微波辐射加热方法成功地合成了PrF3空心纳米粒子和氢氧化镨纳米棒,并以所制备的氢氧化镨纳米棒为前驱体通过热处理得到了氧化镨的纳米棒.对产物进行了X-射线衍射(XRD)、透射电镜(TEM)和电子能谱(EDX)的表征.结果表明,微波合成的PrF3为球形形貌的中空纳米粒子,并具有均匀的粒径大小.微波合成的氢氧化镨纳米棒具有高的结晶度和纯度.实验结果表明,较长的微波加热时间和较高的碱浓度有利于结晶度高的氢氧化镨纳米棒的形成.初步讨论了微波条件下合成氟化镨中空纳米粒子和氢氧化镨纳米棒的形成机理.