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以Co(NO_3)_2·6H_2O和Ni(NO_3)_2·6H_2O为钴源和镍源,采用溶剂热法一步合成了Co(OH)_2/Ni(OH)_2复合材料,通过煅烧该复合材料可得到NiCo_2O_4。采用XRD、SEM、BET等对材料进行了表征,结果表明,Co(OH)_2/Ni(OH)_2复合材料是薄片组成的花状形貌,比表面积为37. 48m~2/g。电化学性能测试表明,Co(OH)_2/Ni(OH)_2复合材料比NiCo_2O_4具有更高的比电容值和容量保持率。在0. 5A/g的电流密度下,复合材料比电容值可达到1097. 8F/g,而NiCo_2O_4比电容值仅为86. 1F/g。因此,与煅烧后的NiCo_2O_4材料相比,Co(OH)_2/Ni(OH)_2复合材料具有更加优良的电化学性能,这为高性能超级电容器材料的制备提供了一个新思路。 相似文献
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β-Co(OH)2 and Mg(OH)2 nanoplates were synthesized via a facile template-free hydrothermal approach. The different conditions of preparation and catalytic properties of the products were studied and discussed. The products were characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, selected area electron diffraction(SAED), and gas chromatograph. 相似文献
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Mg(OH)2晶须的制备 总被引:1,自引:0,他引:1
以MgCl2为原料,NaOH为沉淀剂,研究了它们的浓度配比、反应温度、晶化温度、晶化时间、晶化方式等因素对形成Mg(OH)2晶须的影响. 结果表明,当n(MgCl2): n(NaOH)=1.20: 1.92、混合温度Tm=86 ℃、晶化温度Tc=100 ℃、晶化时间Time=5.5 h时,可以得到发育不完全的初级Mg(OH)2晶须. 若改用水热法晶化,可得到发育较好的Mg(OH)2晶须. 在此基础上,若在NaOH溶液中加入一定量的有机溶剂OR(NaOH浓度不变)时,即可得到发育更完善的Mg(OH)2晶须. 电子显微镜照片显示,粒子呈晶须形状,粒度分布均匀,分散性好,晶形好,纯度高. 并对晶须生长机理进行了初步分析. 相似文献
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Aluminum-cobalt co-substituted α-Ni(OH)2 was prepared by means of the titration method in a buffer solution, the structure was characterized by XRD analysis. With above mentioned α-Ni(OH)2 as the positive electrode of a nickel-metal hydride cell, the discharge performances were examined by constant-current charge-discharge experiments. In comparison with the electrodes made of aluminum substituted or cobalt substituted Ni(OH)2 materials, the aluminum-cobalt co-substituted composite electrodes possess an excellent electrochemical performance and are of practical significance. 相似文献
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研究了稀土偶联剂 (ReC)对Mg(OH) 2 的表面改性作用及PP/Mg(OH) 2 体系的燃烧性能、流动性能、力学性能及老化性能。稀土偶联剂可显著改善Mg(OH) 2 在非极性介质中的分散性 ;PP/Mg(OH) 2 体系当Mg(OH) 2 填充量超过 5 0 %时 ,氧指数 (OI)≥ 2 8.5 ,但这时冲击强度不足纯PP的 30 % ,熔体流动速率 (MFR)低于 0 .6g/1 0min ;而填料用 2 .5 % (质量 )ReC处理后 ,填充量为 5 0 %的体系冲击强度接近纯PP ,MFR达 2 .8g/1 0min ;Mg(OH) 2对体系光氧老化过程有加速作用 ,而对热氧老化过程有阻滞作用 ;稀土偶联剂对体系光氧老化过程有轻微的促进作用 ,而对热氧老化过程无明显影响 相似文献
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以氯化钴为原料,聚乙烯吡咯烷酮(PVP)为分散剂,采用化学沉淀的方法制备出由纳米粒子组成的片状α-Co(OH)2.用红外光谱对所制样品的组分进行分析,用X射线衍射和场发射扫描电子显微镜表征产物的结构和形貌,用循环伏安和恒电流充放电等测试方法对其电化学性能进行研究.研究结果表明,由纳米粒子组成的片状α-Co(OH)2表现出优良的电化学性能,单电极比电容高达1220 F/g. 相似文献
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应用恒电位法测定锌合金阳极在不同pH值的Ca(OH)2溶液中的极化曲线,X-射线衍射分析了该锌合金阳极的腐蚀产物.实验表明:在不同pH值的碱性溶液中锌合金阳极表现出完全不同的电化学行为:在不稳定钝化区内出现了3个零电流电位;根据锌合金阳极在Ca(OH)2溶液中极化曲线测定了活化区内各不同pH值下的零电流电位、腐蚀电流密度,以及钝化区间内的维钝电流密度、钝化膜破裂电位等电化学参数;绘制电位-pH图,并与纯锌-水系的电位-pH图进行比较. 相似文献
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ZHANG Qiang * LU Jie-binCollege of Materials Science Engineering Beijing University of Chemical Technology Beijing P. R. China 《高等学校化学研究》2002,18(4):424-426
IntroductionIt is well known that PVC is a kind of valuableplastic and used in many fields.But PVC isunstable against heat and light,and at the heat-molding step,the thermal decomposition of it maytake place.Finally,the decomposition will reducethe mechanical strength and lose otherproperties ofPVC.In order to overcome those disadvantages,athermal stabilizer is added in the PVC material toreduce the thermal decomposition,and organiccompounds of metals such as Sn,Pb,Ca,Ba,Znand Cd are u… 相似文献
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利用热重分析仪并借助电导率测定法探讨了Al(OH)3和Mg(OH)2对PVC热解特性的影响,简要分析了其机理。结果表明:加入Al(OH)3和Mg(OH)2后均能增加PVC体系在第一阶段的最大热解速率和残炭量,最大热解速率增加约1倍,残炭量增加约4倍。并且分解产生的结晶水吸收大量的热量,惰性金属氧化物也有利于成核、炭层生长和凝聚,有着明显的阻燃和抑烟作用。HCl毒性气体的释放主要集中在体系的第一阶段,Al(OH)3能促使HCl提前释放,HCl的释放总量增加,Mg(OH)2也能促使HCl提前释放,但HCl的释放总量却是减少的。 相似文献
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超细碳酸钙填充聚氯乙烯糊触变性能研究 总被引:6,自引:0,他引:6
超细碳酸钙填充聚氯乙烯糊触变性能研究陈飞跃,许勇,胡黎明(华东理工大学技术化学物理研究所,上海,200237)关键词超细碳酸钙,触变性,聚氯乙烯糊,表面改性,屈服应力触变性是一种重要的工艺参数和性能指标,例如,汽车底漆用聚氯乙烯糊就要求有良好的触变性... 相似文献
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酯基硫醇锡PVC热稳定剂的合成 总被引:5,自引:1,他引:4
酯基硫醇锡PVC热稳定剂的合成魏荣宝*梁娅韩宝成卢世荣高铁男(天津理工学院化工系天津300191)关键词酯基硫醇锡,制备,PVC热稳定剂1996-08-20收稿,1996-12-12修回天津市自然科学基金资助项目酯基硫醇锡是70年代末开发的一类PVC... 相似文献
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F. Pruneda J. J. Suñol F. Andreu-Mateu X. Colom 《Journal of Thermal Analysis and Calorimetry》2005,80(1):187-190
Summary Nitrile butadiene rubber (NBR) and NBR/PVC blends were produced using 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ) or not as antioxidant. Controlled ozone degradation was performed in several samples. Thermal, compositional and morphological analysis was performed by means of differential scanning calorimetry, thermogravimetry, chemical analysis and scanning electron microscopy. Thermogravimetry analysis shows four mass loss processes related to plastizicer, complex rubber degradation and metallic oxides and other additives. In NBR (NBR/PVC blends) the onset temperature of the first degradation process varies between 227-231°C (259-262°C) and the apparent activation energy between 26 and 36 kJ mol-1 (36-57 kJ mol-1), the NBR/PVC samples non degraded presents the higher thermal stability. 相似文献
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Thermal degradation of PVC cable insulation studied by simultaneous TG-FTIR and TG-EGA methods 总被引:2,自引:0,他引:2
Beneš M. Milanov N. Matuschek G. Kettrup A. Plaček V. Balek V. 《Journal of Thermal Analysis and Calorimetry》2004,78(2):621-630
Thermogravimetry (TG/DTG) coupled with evolved gas analysis (MS detection) of volatiles was used to characterize the thermal
behavior of commercial PVC cable insulation material during heating in the range 20-800°C in air and nitrogen, respectively.
In addition, simultaneous TG/FTIR was used to elucidate chemical processes that caused the thermal degradation of the sample.
A good agreement between results of the methods was found. The thermal degradation of the sample took place in three temperature
ranges, namely 200-340, 360-530 and 530-770°C. The degradation of PVC backbone started in the range 200-340°C accompanied
by the release of HCl, H2O, CO2 and benzene. The non-isothermal kinetics of thermal degradation of the PVC cable insulation in the temperature range 200-340°C
was determined from TG results measured at heating rates of 1.5, 5, 10, 15 and 20 K min-1 in nitrogen and air, respectively. The activation energy values of the thermal degradation process in the range 200-340°C
of the PVC cable insulation sample were determined from TG results by ASTM method.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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稀土PVC热稳定剂作用模式及协同效应研究 总被引:3,自引:0,他引:3
稀土化合物对PVC良好的稳定作用,并存在广泛的协同效应。探索了一种计算机辅助研究稀土PVC热稳定剂作用模式及效应的方法,可以预测稳定剂的稳定效能。结果表明,在稀土硬脂酸盐及同类稳定剂中,曲线回归方程参数有效地反映了热稳定剂类型的差别;引入协同效应函数,不仅提高了回归方程的可信度,而且能反映协同效应的形成规律。 相似文献
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脂溶性金属酞菁的合成及其作为PVC膜电极载体的研究李俊忠,庞新宇,陆素,高德,俞汝勤(湖南大学化学化工系,长沙,410082)关键词脂溶性金属酞菁,载体,PVC膜电极金属酞菁由于价廉、稳定及其所具有的氧化还原性、光导电和催化等独特的物理化学性质,已在... 相似文献
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Sayed S. Badawy Yousry M. Issa Waheed F. El-Hawary Manal S. Ashour 《Mikrochimica acta》2001,136(1-2):1-7
A PVC membrane electrode selective for cetyldimethylethylammonium (CDEA) ion was prepared. The active element is a plasticized
poly vinyl chloride membrane containing a dissolved ion associate complex of CDEA with phosphotungstic acid (PTA). The electrode
showed a near-Nernstian response within the CDEA+ concentration range 2.34 × 10−6 to 1.96 × 10−4 M at 25 ± 1^C, good selectivity, and is usable within the pH range 3.5–9.0. The isothermal temperature coefficient of the electrode amounted
to −0.00012 V/°C. The electrode has been used for the direct determination of cetyldimethylethylammonium bromide either by
the standard addition method or by potentiometric titration against PTA.
Received January 1, 1998. Revision June 13, 2000. 相似文献