SnO2纳米晶修饰多孔Co3O4纳米棒的制备及气敏性能研究

以CoCl2.6H2O和CO(NH2)2为原料采用水热法合成多孔Co3O4纳米棒,之后通过自组装的方法将SnO2纳米晶修饰到多孔Co3O4纳米棒上。研究了SnO2纳米晶修饰对多孔Co3O4纳米棒气敏性能的影响。气敏测试结果表明SnO2纳米晶的修饰明显增强了多孔Co3O4纳米棒对CH3CH2OH和H2S的响应,对CH3CH2OH和H2S的检出下限分别达到5.0×10-6和1.0×10-6。     

Zn2(OH)3VO3∶Eu3+纳米晶的水热合成及发光性能

以NaVO3、Zn(NO3)2·6H2O为原料,采用水热法合成了铕离子掺杂Zn2(OH)3VO3纳米晶体。运用X射线粉末衍射、扫描电子显微镜、荧光测试仪对纳米晶进行了表征,研究了水乙醇体系不同pH值对产物晶相、微观形貌及荧光性能的影响。在溶剂体系pH值为7~10时,得到片状的Zn2(OH)3VO3,而在pH值为4~6和11~12时得到Zn3(OH)2V2O7·2H2O,表明强酸性和强碱性的溶剂体系都不太适合Zn2(OH)3VO3的合成,而最佳的合成体系为中性偏碱性;荧光测试表明在pH=10的水乙醇体系下合成的Zn2(OH)3VO3∶8%Eu3+纳米片的荧光性能最好,其中发射主峰位于612nm处。     

锂离子电池正极材料Li3V2-2x/3Mnx（PO4）3的溶胶凝胶法合成和电化学性能

以CH3COOLi·2H2O、V2O5、Mn(CH3COO)2·4H2O、(NH4)2HPO4和蔗糖为原料,采用溶胶–凝胶法合成了掺锰磷酸钒锂/碳(Li3V2-2x/3Mnx(PO4)3/C)复合正极材料,用XRD、XPS、SEM、电化学性能对样品进行了表征.测试结果表明,少量锰的掺杂并未改变Li3V2(PO4)3/C的单斜结构,Li3V1.94Mn0.09(PO4)3中的Mn和V分别以+2和+3价存在,其颗粒类似球形,直径比较均匀且小于200 nm,并表现出良好的电化学性能.在0.1C倍率和3.0～4.8 V电压内,该样品的首次充、放电容量分别为182.1和168.8 mAh/g,放电效率高达92.69%,而且100次循环后,其放电比容量仍是首次放电容量的77.4%.     

炭分子筛的结构和表面性质对其吸附分离CH4/N2和CO2/N2的影响

对日本Takeda(CMS-1)、Kuraray(CMS-2)和德国BF(CMS-3)3种炭分子筛(CMS)的孔结构和表面官能团进行了表征,分析了它们对CH4/N2和CO2/N2的吸附平衡和吸附动力学分离性能,以及CMS的结构与表面性质对吸附性能的影响。结果表明,CMS-1和CMS-2可实现CH4/N2的动力学分离,还可实现N2/CO2的平衡分离;CMS-3平衡分离CH4/N2和CO2/N2的效果要优于动力学分离。孔结构是影响炭分子筛分离性能的直接因素,孔径分布的差异使CMS-1和CMS-2对CH4/N2的位阻-动力学分离效应表现得更为明显;表面含氧官能团有利于提高炭分子筛的吸附分离性能。     

La2O3掺杂MoSi2的SHS合成及其性能研究

以Mo粉、Si粉和La2O3为原料,通过自蔓延高温燃烧合成(SHS)的方法制备了La2O3掺杂的MoSi2材料．研究表明,掺杂剂La2O3的加入对MoSi2燃烧合成过程的热力学和动力学具有明显的影响．并通过XRD和SEM对燃烧合成产物的物相组成和形貌进行了分析,发现La2O3的加入对合成产物的物相组成没有明显影响,但可以大大降低合成产物的晶粒尺寸．同时,力学性能研究结果表明,La2O3的加入可以提高MoSi2材料的室温断裂韧性．     

(1-x)Pb(Fe2/3W1/3)O3-xPb(Mg1/2W1/2)O3多铁性材料的有序结构及磁性能

以无机盐为前驱体,利用溶胶-凝胶法固溶合成了(1-x)Pb(Fe2/3W1/3)O3-xPb(Mg1/2W1/2)O3多铁性固溶体.XRD分析表明,在0≤x≤1.0的掺杂范围内,700℃煅烧所得产物都具有钙钛矿结构;x=0时得到的纯Pb(Fe2/3W1/3)O3为长程无序结构,x=1.0时可获得完全有序的纯Pb(Mg1/2W1/2)O3相,其单胞为Pb(Fe2/3W1/3)O3单胞的2倍;当0相似文献   

负载TiO2活性炭电极材料的制备工艺

采用溶胶-凝胶法对活性炭进行载钛改性,制备TiO2/AC电极材料。通过正交实验考察改性过程中无水乙醇(C2H5OH)、去离子水(H2O)、冰乙酸(CH3COOH)、盐酸(HCl)以及活性炭(AC)这五种成分的最佳加入量。利用比表面积及孔径分析仪(BET)、电化学工作站分别对材料的比表面积和电极比电容进行表征。结果表明,材料组成的最佳加入量为无水乙醇30mL、冰乙酸2mL、盐酸0.3mL、去离子水4.5mL、活性炭2g。各因素对电极的电化学性能影响大小依次为:AC量>CH3COOH量>C2H5OH量>去离子H2O量>HCl量。载钛后活性炭比表面积从680.5m2/g降为523.35m2/g,降低23.1%;比电容从116F/g升到135F/g,升高16.4%。活性炭材料负载TiO2处理后,可以加速电极双电子层的形成,提高电极比电容量。     

水热可控合成多面体BiFeO3颗粒

以Bi(NO)3·5H2O和Fe(NO)3·9H2O为水热反应原料,选择KOH作为矿化剂合成单相BiFeO3.通过调节KOH浓度和升降温速率可控合成了规则的大尺度多面体BiFeO3颗粒.发现高碱浓度有利于合成规则多面体BiFeO3颗粒,合适的水热降温速率是影响高结晶度BiFeO3颗粒合成的重要因素之一.当KOH浓度为6和8 mol/L,降温速率为0.2℃/min时,产物为高结晶度准立方和截角立方颗粒,当降温速率调节为0.1℃/min时,产物为表面粗糙的立方八面体和截角八面体颗粒.当KOH浓度为8 mol/L,降温速率约为2℃/min时,产物为表面粗糙且有孔洞的截角立方颗粒.通过扫描电镜图片观察到其形貌演变过程并解释了大尺度多面体BiFeO3颗粒的形成机制.     

模板剂对Sm2O3微晶的生长及光学性能的影响

以SmCl3·6H2O和NaOH为主要原料,异丙醇为溶剂,借助不同模板剂对Sm2O3微晶进行可控合成。在200℃溶剂热条件下反应48h后得到前驱体,经800℃热处理1h后制得了不同结构和形貌的Sm2O3微晶。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和Lambda 950分光光度计分别对产物的物相、形貌和光学性能进行表征,并研究了不同模板剂对产物的物相、形貌及光学性能的影响。结果表明,不同模板剂对产物的结构、尺寸及性能产生不同的影响。以CTAB作为模板剂时,制备了含有立方相和单斜相两相的、六方片状结构的Sm2O3微晶,其禁带宽度为4.828eV。     

Y2O3:Eu3+纳米晶的制备及其光学性能研究

以NaOH,Y(NO3)3.6H2O和Eu(NO3)3.6H2O为前驱体,通过添加络合剂PEG-2000,采用水热法,成功地合成了Y2O3∶Eu3+纳米棒和纳米管,并采用先进的测试手段对其结构和性能进行了表征与测试。探讨了Y2O3∶Eu3+纳米棒和纳米管的生长机制,同时研究了Y2O3:Eu3+纳米晶的光致发光性能。研究结果表明,水热温度、反应时间、NaOH的添加量和PEG-2000对产物形貌有着非常重要的影响,所制备的材料具有Eu3+的特征红光发射,并在Eu3+的掺杂量为5%(摩尔分数)时样品发光最好。     

镀锌层三价铬钝化膜腐蚀行为的研究

通过盐雾试验、扫描电镜、电化学测试和X射线光电子谱(XPS)等手段,研究了三价铬盐(TC)和三价铬盐加丙烯酸树脂(TCA)两种钝化液制得钝化膜的腐蚀行为及其耐蚀机理.结果表明,热浸镀锌层经TC、TCA钝化处理后,均能有效提高其抗腐蚀能力;SEM发现TC钝化膜表面出现微裂纹,TCA钝化膜表面呈网状的胞状组织覆盖于镀锌层之上,这种致密性好、稳定性高的膜层起到了更好的机械隔离作用,并能抑制钝化膜中微裂纹的产生,所以耐蚀性能大大提高;XPS分析表明,TC及TCA钝化膜层铬是以CrOOH或Cr(OH)3三价存在.此外,TCA膜层中还含有四价C、五价N.     

核壳结构纳米颗粒的研究进展

核壳结构纳米颗粒具有不同于核和壳的物理和化学性能，通过调整核和壳的化学组成、尺寸和形貌，可以调控纳米颗粒的性能，扩展纳米颗粒的应用范围。系统总结了近年来制备核壳结构纳米颗粒的研究进展，讨论了核壳结构纳米颗粒对光学特性的影响。     

Synthesis and electrochemical property of Bi2Se3 nanotubes with laminar surface

A novel hydrothermal method has been developed for the preparation of Bi2Se3 nanotubes with the laminar surface. The method is based on the template-engaged synthesis in which the as-prepared Se nanotubes were used as template reagent. The morphology, constitution and crystalline phase of the products as-obtained were characterized by SEM, XRD and XPS. On the basis of a series of experiments and characterizations, the effect factors (such as the reaction temperature and the atom ratio of Bi and Se in the precursors) and the formation mechanism of the Bi2Se3 nanotubes were discussed. Furthermore, the electrochemical property of the Bi2Se3 nanotubes was determined by the voltammetric technique, and the significant results were obtained.     

自乳化水性环氧树脂的合成

用2,2-二羟甲基丙酸和甲苯二异氰酸酯与双酚A型环氧树脂主链上的仲羟基反应,在环氧树脂主链上引入-COOH基团,制得水性环氧树脂。通过红外光谱分析了产物的结构;讨论了反应溶剂、温度、时间、反应物配比等因素对反应结果的影响。并通过正交试验确定了合成自乳化水性环氧树脂的最优条件。试验结果表明,以丙酮为溶剂,反应温度50℃左右,反应时间4.5h,m(2,2-二羟甲基丙酸)∶m(甲苯二异氰酸酯)∶m(E-44)∶m(二月桂酸二丁基锡)=12∶17∶100∶0.2,制得的水性环氧树脂具有良好的水分散性和优异的固化性能。     

Effects of Surface Treatments on the Performances of Al2 O3 Nano-Particle/Polyimide adhesive

The nano-Al2O3/polyimide composite adhesive was prepared by high-energy chemical and mechanical handing in this paper. The thermally curing process was preliminary determined, furthermore, the effects of n-Al2 O3 on the performance of polyimide adhesive were investigated using SEM. The results were showed that n-Al2 O3 particles were segregated from adhesive to the interface, especially bulk structural defect, which may be the reason why the performance of n-Al2O3/PI adhesive becomes better. However, the detailed mechanism is still to be discussed.     

Synthesis and characterization of nano-PVP/EuL3 luminescent complex

Nano-sized rare earth europium [Eu(III)]-benzoic acid [HL] luminescent complex powders have been synthesized in polyvinylpyrrolidone matrix by precipitation method. The chemical constitution of the complex has been demonstrated as PVP/EuL3 by a combination of elemental analysis, inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and fourier-transform infrared spectroscopy (FT-IR). X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM) have shown that the complex is a new nanocrystal whose structure is totally different from the ligand. Thermogravimetric/Differential thermal analysis (TG/DTA) have indicated that the luminescent complex is thermally stable below 500 degrees C. Photoluminescence spectra (PL) have shown that the nanocomplex can emit Eu3+ characteristic red fluorescence under ultraviolet excitation.     

晶型控制剂对纳米氧化镁形貌的影响

对晶型控制剂的种类及用量进行对比,通过形貌和物相的表征和分析,研究晶型控制剂对纳米氧化镁形貌及分散作用的影响。结果表明:采用羧基类和羟类两种晶型控制剂,一羧基类和一羟基类晶型控制剂生成纳米氧化镁为球形,团聚严重;而多羧基类和多羟类晶型控制剂均有利于纳米氧化镁颗粒沿片状分布;加入不同用量的晶型控制剂,乙二胺四乙酸用量为6 mg/L时,有利于纳米氧化镁颗粒沿片状分布,且氧化镁晶粒度仅为26.13 nm,聚乙二醇用量为1.2 mg/L时较利于纳米氧化镁生成片状。     

聚-3-羟基丁酸酯的化学合成和在生物医学上的应用

对近年来聚-3-羟基丁酸酯及其共聚物的化学法合成、聚合机理研究以及在药物释放、组织工程材料等领域的应用作了广泛而深入的总结和评述,并展望了聚合物材料的制备及在生物医学领域中的研究和发展前景.     

Electrical and optical study on modified Thiacalix(4)arene sensing molecules: Application to Hg ion detection

In this work, p-tert-butylthiacalix[4]arene with amide moiety (TCA amide) has been used as a receptor material for Hg²⁺ detection. The TCA amide/gold electrodes were used as Hg²⁺ sensor. Several conditions were optimised to enhance the sensitivity of the ion sensor, with a detection limit of about 10^− 4 M. At lower concentrations, the optical absorption technique was used to study the affinity of TCA amide/Hg²⁺. The evolution of the optical signal with Hg²⁺ concentration gives an insight into the TCA amide/Hg²⁺ interaction and shows the opportunity to use TCA amide molecules for Hg²⁺ opto chemical sensor.     

Surface characterization of sol-gel derived indium tin oxide films on glass

Indium tin oxide (ITO) films containing different In : Sn atomic ratios, viz. 90 :10, 70 :30, 50 : 50, 30 :70, were deposited on two types of glass substrates by sol-gel spinning technique. XPS analysis of the films was done under as-received and after-sputtering conditions. The narrow spectra obtained for the Na1s, In3d, Sn3d and O1s have been discussed. Oxygen was found to exist in three chemical environments in as-received samples due to the existence of (i) environmental hydroxyl (-OH) group, (ii) crystalline ITO and (iii) amorphous ITO; but it was in two chemical environments, (ii) and (iii), after surface cleaning by sputtering. The presence of both tin metal and tin oxides was confirmed by the peak analysis of Sn3d. The In : Sn atomic ratio taken in the precursor sols did not change considerably in the case of developed films of low Sn content, but considerable change was observed in the films having high Sn content.