前驱液浓度对微乳液法合成纳米氧化锆粉体结构与性能的影响

采用水／环己烷／Triton X-100／正己醇四元油包水体系，通过微乳液法制备了纳米ZrO2粉体，用XRD、TEM、TG-DTA等对所制备的纳米粉体进行了表征，并重点研究了体系中增溶的锆盐溶液浓度对ZrO2纳米粒子结构与性能的影响。结果表明，本方法所制备的纳米单斜相ZrO2粉体，其晶粒尺寸可控制在15nm左右；在479℃左右，纳米粉体由无定形转变为晶相；在较低的煅烧温度下，所合成的氧化锆粒子中同时存在着单斜相和四方相两种晶粒，随着煅烧温度的提高，部分四方相会转变为单斜相，到煅烧温度为800℃时，几乎全部转化为单斜相；随着锆盐浓度的增加，所合成粉体的晶型没有太大的变化，均为单斜相，但是晶体结构的完整性略有不同；随着锆盐浓度的增加，所合成粉体的晶粒尺寸有所增大，团聚现象亦有所加重。     

微乳液法合成纳米氧化锆粉体的结构与性能

采用水/环己烷/Triton X-100/正己醇四元油包水体系,通过反相微乳液法制备了纳米ZrO2粉体,用XRD,TEM等对所制备的纳米粉体进行了表征,研究了煅烧温度、pH值、陈化时间对ZrO2纳米粒子结构与性能的影响.结果表明,以单斜相为主的ZrO2纳米粉体,其晶粒尺寸可控制在20 nm左右;随着煅烧温度的提高,ZrO2的结晶程度逐渐提高;随着pH值的提高,少量四方相ZrO2全部转化为单斜相;随着陈化时间的增加,ZrO2颗粒尺寸变大.     

包覆型ZrO2复合Al2O3基陶瓷

用表面被覆3 mol%Y2O3的纳米ZrO2复合Al2O3基陶瓷,研究包覆型ZrO2对Al2O3基陶瓷显微结构及对力学性能的影响.包覆型纳米ZrO2的加入,可改善Al2O3基陶瓷的显微结构.在ZrO2加入量达到9ψ/%时,ZrO2可有效阻碍Al2O3晶粒的异常长大,获得了细晶结构的陶瓷材料.包覆型ZrO2复合Al2O3基陶瓷材料的韧化机制不同于微米级ZrO2复合的材料,主要是通过残余应力场增韧,而不是相变增韧.     

HAP／ZrO2纳米复相生物陶瓷的制备

采用化学反应法制备了纳米羟基磷灰石（HAP）粉体，并采用醇．水溶液加热法制备了纳米ZrO2粉体，通过对制备工艺的研究，同时结合TEM等分析测试手段对获得的纳米粉体进行了成分、颗粒尺度分布和微观形态分析。控制HAP和ZrO2的不同配比，分别选择40％和60％含量的HAP，采用热压烧结技术制备了HAP／ZrO2纳米复相生物陶瓷材料。分析了烧结温度、烧结时间及HAP含量等因素对HAP／ZrO2陶瓷材料的影响。确定了烧结工艺参数，即烧结温度1300℃，烧结压力30MPa及烧结时间1h，并对纳米生物陶瓷的微观组织和性能进行了分析测试，并采用模拟体液研究了该材料的体外生物相容性。结果表明：在短时烧结过程中HAP与ZrO2颗粒间没有反应发生，且该生物陶瓷材料具有无毒、无过敏等特点。     

纳米晶WC-10Co硬质合金复合粉末的烧结行为及性能

研究了机械合金化制备的纳米晶WC-10Co复合粉末的真空烧结特征，分析了孔隙度、显微硬度与烧结时间和温度的关系，考察了改性ZrO2纳米粉体对烧结的作用。结果表明：在1325℃，15min的烧结条件下，样品的相对密度达到了98.6％；显微硬度随着烧结时间的延长和烧结温度的升高先增加后降低，在1325℃烧结15min条件下，合金的最大硬度为22950MPa；改性ZrO2纳米粉体既有利于晶粒长大的控制，同时又有利于材料致密化的进行，可以显著的提高烧结合金的性能。     

ZnO掺杂纳米CeO2的共沸蒸馏法合成

采用化学共沉淀法结合正丁醇共沸蒸馏处理前驱体合成了ZnO掺杂纳米CeO2颗粒,通过XRD,DSC/TG,IR,TEM,原子吸收光谱以及紫外透过率分析等方法对其结构和性能进行了表征;并根据XRD线宽法,由Scherrer公式计算其晶粒尺寸,研究了共沸蒸馏、ZnO掺杂、以及焙烧温度和时间对CeO2纳米晶粒尺寸的影响.结果表明正丁醇共沸蒸馏法能有效脱除前驱体凝胶中的水分,防止干燥和焙烧过程中硬团聚的形成,从而得到粒径更小、分布更均匀、分散性更好的纳米CeO2颗粒;2 mol%～10 mol%掺杂ZnO能与纳米CeO2形成固溶体,且掺入量增加引起纳米CeO2晶粒有所增大;随焙烧温度提高,ZnO掺杂纳米CeO2晶粒显著长大,而高温下随焙烧时间延长,其晶格进一步趋于完整,晶粒尺寸增加;纳米CeO2具有良好的可见光透过和紫外光吸收能力,ZnO掺杂不会影响纳米CeO2的紫外遮蔽效果.     

ZnO掺杂纳米CeO2的共沸蒸馏法合成

采用化学共沉淀法结合正丁醇共沸蒸馏处理前驱体合成了ZnO掺杂纳米CeO2颗粒,通过XRD,DSC/TG,IR,TEM,原子吸收光谱以及紫外透过率分析等方法对其结构和性能进行了表征;并根据XRD线宽法,由Scherrer公式计算其晶粒尺寸,研究了共沸蒸馏、ZnO掺杂、以及焙烧温度和时间对CeO2纳米晶粒尺寸的影响.结果表明:正丁醇共沸蒸馏法能有效脱除前驱体凝胶中的水分,防止干燥和焙烧过程中硬团聚的形成,从而得到粒径更小、分布更均匀、分散性更好的纳米CeO2颗粒;2 mol%～10 mol%掺杂ZnO能与纳米CeO2形成固溶体,且掺入量增加引起纳米CeO2晶粒有所增大;随焙烧温度提高,ZnO掺杂纳米CeO2晶粒显著长大,而高温下随焙烧时间延长,其晶格进一步趋于完整,晶粒尺寸增加;纳米CeO2具有良好的可见光透过和紫外光吸收能力,ZnO掺杂不会影响纳米CeO2的紫外遮蔽效果.     

纳米组织锆合金氧化过程中ZrO2晶粒生长特性

研究了673 K,10.3 MPa条件下纳米锆合金氧化膜中ZrO2晶粒尺寸长大规律.结果表明,在纳米结构基底上形成的ZrO2,晶粒尺寸均小于在粗晶基底上所形成的ZrO2晶粒尺寸;在纳米结构基底上形成的ZrO2晶粒长大速率小于在粗晶基底上所形成的ZrO2晶粒长大速率.组织纳米化促进了更小尺寸ZrO2的形成,影响了ZrO2晶粒长大动力学过程.     

以双(2-氨基烟酸)铜(Ⅱ)微晶片为原料制备介孔结构CuO纳米颗粒的光催化性能（英文）

基于铜络合物的分解性质,提出一种制备具有介孔结构CuO纳米颗粒的简易方法。通过2-氨基烟酸(Hanic)与硝酸铜(Ⅱ)反应,制备一种具有微晶片行貌的新型铜络合物[Cu(anic)_2]·0.75H_2O(anic=2-氨基烟酸根)。元素分析和傅里叶红外光谱(FTIR)分析结果表明,该铜络合物的化学组成为CuC_(12)H_(11.5)N_4O_(4.75)。铜络合物在550℃烧结4 h后由微晶片结构转变为具有介孔结构的CuO纳米颗粒。经烧结过程后,铜络合物中归属于2-氨基烟酸盐的FTIR吸收峰完全消失,证明形成了CuO。XRD分析结果亦证明生成了CuO纯晶。SEM结果表明,CuO纳米颗粒的平均晶粒尺寸为75 mm。CuO纳米颗粒的漫反射光谱分析结果表明,其带隙能约为1.58 eV。在H_2O_2存在及经光照射5 h后,CuO纳米颗粒对罗丹明B的催化降解率达到100%。以上结果表明,所制得的CuO纳米颗粒是一种用于水处理的高效光催化剂。     

纳米结构ZrO2/SiO2粒子的逐层自组装及催化性

用自组装技术合成了以通过溶胶凝胶法得到的纳米ZrO2包覆的SiO2粒子,并研究了其作为固体超强酸的催化性能。样品采用TG-DTA,SEM,EDS,XPS和XRD进行了表征。结果表明:SiO2粒子表面的纳米ZrO2具有较好的均匀性和致密性,ZrO2的含量随覆盖层的增加而增多,纳米ZrO2具有四方相结构;SO42--ZrO2/SiO2固体超强酸具有较好的催化性及重复使用性。     

Pd/ZrO2-Al2O3催化剂中载体制备对CH4转化活性的影响

为推动ZrO2-Al2O3在天然气汽车尾气净化催化剂中的实际应用,并阐明其制备条件对负载催化剂转化活性的影响机制,文章以ZrO2-Al2O3复合氧化物为载体,采用等体积浸渍法制备了Pd/ZrO2-Al2O3催化剂,并在连续流动固定床反应器上研究了ZrO2-Al2O3复合氧化物的制备对催化剂低温CH4氧化活性的影响。结果表明：制备方法中,相比于浸渍法和胶溶法,沉淀法更能提高催化剂活性;锆源、铝源优选中,以Zr(NO3)4为锆源、拟薄水铝石为铝源时能获得较高的催化活性;组分配比中,以w (ZrO2): w (Al2O3)=10:90的催化活性最高。XRD、低温N2吸附、CO脉冲吸附的结构表征表明,ZrO2-Al2O3复合氧化物的大的比表面积、孔容、孔径是促进贵金属Pd分散,提升催化剂低温CH4转化活性的关键因素。     

The Microstructure and Mechanical Behavior Evaluation of Ce-TZP／Al2O3 Nanocomposites

Ce-TZP/Al2O3 nanocomposites were prepared from mixture of self-made Ce-TZP nanometer powder and commercial Al2O3 powder by hot-pressing method. Influences of nanometer ZrO2 particles on the mechanical properties and microstructure of Ce-TZP/Al2O3 ceramics were investigated. Meanwhile, t→m transformation toughening mechanism was investigated by x-ray diffractometry (XRD) method, and deflection of samples under applied stress were recorded too. The results show that when the percentage of ZrO2 was 20%, the mechanical properties and microstructures of materials were preferential. Additionally, TEM observation show that dislocation structures form both in the Al2O3 grain and on the Al2O3 grain boundary.     

（Al，Sb）／ZnO复合氧化物对乙醇气体气敏功能特性的影响

用可溶性无机盐法制备了较宽工作温度范围的纳米(Al，Sb)/ZnO气敏材料。该材料主相属于ZnO纤锌矿结构，并同时存在Sb2O5、Sb6O132种微量杂相。该复合氧化物的平均晶粒为86nm。用制备的氧化物纳米粉做成气敏元件，测试了不同铝含量的纳米材料在2000μg/g浓度乙醇气体下的敏感特性。当铝含量为Al/ZnO=1．5％(mol比，下同)时，对2000μg的乙醇气体的灵敏度最大可达到26。固定Al/ZnO=3％时，掺入不同量锑得到对乙醇气体有更大工作温度范围的纳米复合氧化物材料。同时讨论了掺铝掺锑复合氧化物对敏感气体的物理吸附和化学吸附及其气敏机理。     

Ru/Mn-Ce/TiO2及Ru/TiO2催化剂对丁二酸的催化湿式氧化研究

采用浸渍法制备了2个系列的Ru／Mn-Ce/TiO2及Ru/TiO2催化剂,并用XRD、TEM、BET等方法对催化剂进行表征。在T=270℃和Po2=1．5MPa条件下,在间歇式反应釜中对丁二酸进行降解实验。结果表明60min内丁二酸降解的总有机碳(TOC)去除率为80％～99．8％;在钌含量相同的情况下,Ru／Mn-Ce／TiO2催化剂的催化活性高于Ru/TiO2催化剂;Ru含量较低的情况下,Mn、Ce对提高催化活性有很大作用,但Ru含量增加时Mn、Ce的作用减弱;氢还原的温度对Ru/TiO2系列催化剂的催化氧化活性有明显影响,500℃还原钌所得催化剂对丁二酸的催化氧化活性优于350℃。     

Effect of second introduced phase on magnetotransport properties of La2/3Sr1/3MnO3/0.33(CuO, ZnO, Al2O3) composites

The structure, magnetic and magnetotransport properties of La2/3Sr1/3MnO3(LSMO)/0.33(CuO, ZnO, Al2O3) composites were investigated to explore the role of second introduced phase. The microstructural analysis shows two kinds of grain boundaries: LSMO/LSMO and LSMO/second phase/LSMO. Two maximal resistivities appear in LSMO/0.33CuO and LSMO/0.33ZnO composites while the resistivity of LSMO/0.33Al2O3 decreases monotonically with increasing the temperature from 200 K to 400 K. Moreover, the temperature dependence of magnetoresistance(MR) of LSMO/0.33Al2O3 that decreases monotonically with increasing the temperature is different from that of LSMO/0.33CuO and LSMO/0.33ZnO. A developed two-channel model consisting of scattering model and tunneling model was proposed to fit the resistivity-temperature curves of these composites. The role of second introduced phase and the magnetotransport mechanism of these composites were elucidated.     

Preparation and characterization of ZnO nanometer powder

Hard zinc from thermo-plating zinc factory had been treated for preparation of ZnO nano-powder by chemical precipitation. The ion-type and non-ion-type surface-active reagents were added in different steps and ultrasonic agitation was used in preparing process. TG/DTG was applied to determine thermo-decomposition temperature of the precursor as about 450℃. The product is light yellow, and had been characterized by XRD, SBET and TEM,through which the good dispersing sphere particles with the average diameter of approximately 50 - 60 nm are observed, and the crystal is pure ZnO with hexahedral structure. The cost of preparing nanometer zinc oxide is low.     

Influence of oxygen gas content on the structural and optical properties of ZnO thin films deposited by RF magnetron sputtering at room temperature

Zinc oxide (ZnO) thin films were deposited on sapphire (0001) substrates at room temperature by radiofrequency (RF) magnetron sputtering at oxygen gas contents of 0%,25%,50% and 75%,respectively.The influence of oxygen gas content on the structural and optical properties of ZnO thin films was studied by a surface profile measuring system,X-ray diffraction analysis,atomic force microscopy,and UV spectrophotometry.It is found that the size of ZnO crystalline grains increases first and then decreases with the increase of oxygen gas content,and the maximum grain size locates at the 25% oxygen gas content.The crystalline quality and average optical transmittance (>90%) in the visible-light region of the ZnO film prepared at an oxygen gas content of 25% are better than those of ZnO films at the other contents.The obtained results can be attributed to the resputtering by energetic oxygen anions in the growing process.     

纳米Ce/CuO的改性及室温脱硫性能研究

本文采用直接沉淀法制备出铁、钴和锌元素改性的纳米Ce/CuO脱硫剂,在室温常压条件下吸附含H2S恶臭气体,研究其脱硫活性。通过X射线衍射(XRD),透射电子显微镜(TEM),X射线光电子能谱(XPS)等技术分析了改性元素对纳米Ce/CuO脱硫剂结构的影响,探讨脱硫剂结构变化与脱硫性能的关系。结果表明,改性元素钴添加到纳米Ce/CuO脱硫剂中具有最好的脱硫活性,钴的添加使纳米Ce/CuO脱硫剂的粒径明显变小,材料中存在Cu3 ,且Cu3 /Cu2 的摩尔比值要高于纳米CuO和Ce/CuO样品,说明Co/Ce/CuO表面对脱硫反应有利的氧空位增加;当Co添加量为4.9%时,Co/Ce/CuO脱硫剂的穿透时间可达525min,比Ce/CuO脱硫剂的穿透时间延长了近300min。     

Effects of Oxide-Modified Spherical ZnO on Electrical Properties of Ag/ZnO Electrical Contact Material

Silver-zinc oxide (Ag/ZnO) electrical contact material is widely used as contacts of the medium duty switching devices. Effects of modified ZnO on properties of Ag/ZnO electrical contact material were investigated in this work. NiO and CuO were introduced to modify spherical ZnO by a chemical solution nano-coating method. Ag/ZnO contacts prepared using the modified spherical ZnO were produced by powder metallurgy (PM) method in a muffle furnace in temperature ranges from 750 to 900 °C. Results show that electrical conductivity, stability of relative density, and Vickers’ hardness of Ag/ZnO electrical contact material can be improved by the addition of NiO because of the formation of NiO solid solution Zn_0.2Ni_0.8O. The addition of CuO to Ag/ZnO electrical contact material makes arcing energy and mass loss lower. Since this is attractive for a longer service life, using NiO and CuO co-modified ZnO as a second phase may be a promising way to improve properties of Ag/ZnO electrical contact material. Hence, the presented results could also be useful for the design of a new Ag/ZnO electrical contact material.     

Leaching of chromite ore in concentrated KOH by catalytic oxidation using CuO as catalyst

CuO was used as a catalyst in the concentrated KOH solution to enhance the leaching of chromium from the chromite ore. The impacts of temperature, KOH-to-chromite ore mass ratio, CuO-to-chromite ore mass ratio, and gas flow rate on the chromium leaching rate were investigated. The results indicated that CuO played an important role in improving the chromium leaching rate. The leaching rate reached 98% after leaching for 6 h when CuO was applied, whereas it was only 60.8% without CuO under the same reaction conditions: temperature 230 °C, KOH-to-ore mass ratio 6:1, stirring speed 700 r/min, gas flow rate 1 L/min. According to the kinetics study, the catalytic oxidation was controlled by surface chemical reaction and the activation energy was calculated to be 15.79 kJ/mol when the temperature was above 230 °C. In contrast, without CuO, the rate-determining step was external diffusion and the apparent activation energy was 38.01 kJ/mol.