玻璃粉在陶瓷化硅橡胶中的应用

陶瓷化高分子材料具有优异的阻燃和防火性能,在国外已经有公司制备了这种材料来代替传统的防火材料。以硅橡胶为基体,通过添加玻璃粉,制备了一种陶瓷化高分子材料,研究了玻璃粉用量对硅橡胶力学性能和电学性能的影响,通过SEM观察了瓷化物表面和断面的形貌。结果显示,瓷化物表面比较致密,气孔较少,有一些玻璃相形成;断面存在大量气孔,具有较好的瓷化性能,瓷化物致密而又坚硬,可以抵抗至少1000℃的高温。随着玻璃粉添加量的提高,硅橡胶的流动性变差,硫化速率加快,拉伸强度和断裂伸长率都有不同程度的下降,邵氏硬度A一直上升,体积电阻率和表面电阻率则都呈现出先增大后减小的趋势。     

磁性离子印迹聚合物的制备研究进展

离子印迹技术是分子印迹技术的一个重要分支。离子印迹聚合物具有预定识别性,制备简单、价格低廉、稳定性好,对模板离子表现出较高的选择性和亲和性等优点,但离子印迹材料在完成吸附使命后从反应体系中分离困难。将离子印迹技术与磁性技术相结合制备的磁性离子印迹聚合物,不仅具有特定的分子识别位点,而且具有磁响应特性,在外加磁场作用下,容易分离回收。此文综述了近年来磁性离子印迹聚合物的研究进展状况,同时提出了目前该领域存在的问题和发展趋势。     

纤维素负载金属催化剂研究进展

高分子负载金属催化剂由于催化活性好、稳定性高、反应后容易和产物分离、易于从反应体系中分离回收和重复使用等原因,近年来成为了人们的研究热点之一。纤维素是自然界中储量最丰富的天然高分子,其在大多数有机溶剂中稳定,且其比表面积大,结构中含有大量羟基,可参与许多反应。本文以自然界中储量丰富、无毒、可降解、可再生的天然高分子纤维素为载体,按照纤维素负载金属催化剂制备方式的不同,综述了纤维素负载Pd、Ag、Au、Cu等金属催化剂的制备及其在有机反应中的应用。     

用于电致发光器件的蓝光聚合物材料研究进展

聚合物电致发光材料成型加工简便、可大面积生产,可应用于大面积平板显示及固体照明器件。与红、绿光聚合物发光材料相比,蓝光聚合物电致发光材料在发光性能、材料寿命等方面仍然存在较大差距,这成为全色显示的瓶颈。通过在聚合物主链上引入大体积的取代基或侧链、形成具有三维空间共轭效应的支化结构或能量可转移的主客体结构等,来改善溶解性和光物理性能等,从而得到发光效率高、色纯度好、热力学性能优异且材料加工性能良好的蓝光聚合物电致发光材料。本文从材料设计的角度简要介绍了国内外蓝光聚合物发光材料的主要研究进展。     

Interconnected sandwich structure carbon/Si-SiO2/carbon nanospheres composite as high performance anode material for lithium-ion batteries

In the present work,an interconnected sandwich carbon/Si-SiO2/carbon nanospheres composite was prepared by template method and carbon thermal vapor deposition（TVD）.The carbon conductive layer can not only efficiently improve the electronic conductivity of Si-based anode,but also play a key role in alleviating the negative effect from huge volume expansion over discharge/charge of Si-based anode.The resulting material delivered a reversible capacity of 1094 mAh/g,and exhibited excellent cycling stability.It kept a reversible capacity of 1050 mAh/g over 200 cycles with a capacity retention of 96%.     

Oxygen permeation and phase structure properties of partially A-site substituted BaCo_(0.7)Fe_(0.225)Ta_(0.075)O_(3-δ) perovskites

Ba0.9R0.1Co0.7Fe0.225Ta0.075O3-δ(BRCFT, R = Ca, La or Sr) membranes were synthesized by a solid-state reaction. Metal cation Ca2+,La3+or Sr2+doping on A-site partially substituted Ba2+in BaCo0.7Fe0.225Ta0.075O3-δoxides, and its subsequent effects on phase structure stability, oxygen permeability and oxygen desorption were systematically investigated by XRD, TG-DSC, H2-TPR, O2-TPD techniques and oxygen permeation experiments. The partial substitution with Ca2+, La3+or Sr2+, whose ionic radii are smaller than that of Ba2+, succeeded in stabilizing the cubic perovskite structure without formation of impurity phases, as revealed by XRD analysis. Oxygen-involving experiments showed that BRCFT with A-site fully occupied by Ba2+exhibited good oxygen permeation flux under He flow, reaching about 2.3mL min-1 cm-2at 900 ℃ with 1 mm thickness. Of all the membranes, BLCFT membrane showed better chemical stability in CO2, owing to the reduction in alkalinity of the mixed conductor oxide by La doping. In addition, we also found the stability of the perovskite structure under reducing atmospheres was strengthened by increasing the size of A-site cation(Ba2+La3+Sr2+Ca2+).     

Graphene oxide assisted facile hydrothermal synthesis of LiMn0.6Fe0.4PO4 nanoparticles as cathode material for lithium ion battery

Assisted by graphene oxide（GO）,nano-sized LiMn0.6Fe0.4PO4 with excellent electrochemical performance was prepared by a facile hydrothermal method as cathode material for lithium ion battery.SEM and TEM images indicate that the particle size of LiMn0.6Fe0.4PO4（S2）was about 80 nm in diameter.The discharge capacity of LiMn0.6Fe0.4PO4 nanoparticles was 140.3 mAh-g^1 in the first cycle.It showed that graphene oxide was able to restrict the growth of LiMn0.6Fe0.4PO4 and it in situ reduction of GO could improve the electrical conductivity of LiMn0.6Fe0.4PO4 material.     

Catalytic performance of cement clinker supported nickel catalyst in glycerol dry reforming

The paper reports the development of cement clinker-supported nickel （with metal loadings of 5 wt%, 10 wt%, 15 wt% and 20 wt%） catalysts for glycerol dry （CO2） reforming reaction. XRF results showed that CaO constituted 62.0% of cement clinker. The physicochemical characterization of the catalysts revealed 32-folds increment of BET surface area （SBET） with the addition of nickel metal into the cement clinker, which was also corroborated by FESEM images. Significantly, XRD results suggested different types of Ni oxides formation with Ni loading, whilst Ca3SiO5 and Ca2Al0.67Mn0.33FeO5 were the main crystallite species for pure cement clinker. Temperature-programmed reduction analysis yielded three domains of H2 reduction peaks, viz. centered at approximately 750 K referred to as type-Ⅰ peaks, another peaks at 820 K denoted as type-Ⅱ peaks and the highest reduction peaks, type-Ⅲ recorded at above 1000 K. 20 wt% Ni was found to be the best loading with the highest XG and H2 yield, whilst the lowest methanation activity. Syngas with lower H2/CO ratios （0.6 to 1.5） were readily produced from glycerol dry reforming at CO2-to-Glycerol feed ratio （CGR） of unity. Nonetheless, carbon deposit comprised of whisker type （Cv） and graphitic-like type （Cc） species were found to be in majority on 20 wt%Ni/CC catalysts.     

Nano-crystalline FeOOH mixed with SWNT matrix as a superior anode material for lithium batteries

Nano-crystalline FeOOH particles(5～10 nm) have been uniformly mixed with electric matrix of single-walled carbon nanotubes(SWNTs)for forming FeOOH/SWNT composite via a facile ultrasonication method. Directly using the FeOOH/SWNT composite(containing 15 wt%SWNTs) as anode material for lithium battery enhances kinetics of the Li+insertion/extraction processes, thereby effectively improving reversible capacity and cycle performance, which delivers a high reversible capacity of 758 mAh g-1under a current density of 400 mA g-1even after 180 cycles, being comparable with previous reports in terms of electrochemical performance for FeOOH anode. The good electrochemical performance should be ascribed to the small particle size and nano-crystalline of FeOOH, as well as the good electronic conductivity of SWNT matrix.     

有机二元酸-水体系中In(OH)_3/In_2O_3微纳材料的制备与表征

本文利用系列有机二元酸-水体系作为制备In(OH)3纳米晶体介质,采用低温水热法成功制备了不同形貌和尺寸的In(OH)3为纳材料。利用扫描电镜(SEM)、透射电镜(TEM)、X-射线衍射(XRD)、傅立叶红外光谱仪(FT-IR)和拉曼光谱仪(Raman)等手段分别对材料的形貌、结构和物相等进行了表征与分析。实验结果表明,通过本研究方法,在己二酸水体系中可以得到较均一的尺寸在300-400 nm范围的In(OH)3球形粒子,而在癸二酸水体系中则得到棒状和片状混杂的In(OH)3纳米颗粒。样品在450°C条件下焙烧4 h后,可获得相应的具有良好形貌继承性的In2O3微纳材料。