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直接由工业Sb4O5Cl2合成SbOCl阻燃剂 总被引:1,自引:0,他引:1
以湿法锑白工艺中的中间产物Sb4O5Cl2为原料,在常温(25℃左右)、低酸([H^ ]<3.1mol/L)的温和条件下,合成了高纯度、高白度的微细SbOCl阻燃剂。最佳合成条件为:搅拌速度大于40s^-1,反应时间大于16h,Csb^3 ≥290g/L,这时固体Sb4O5Cl2的转化率达100%,产物平均粒度5.90μm,颗粒为立方晶体。测试表明,产物SbOCl的阻燃协效性能优于超细Sb2O3,且能降低色料用量,提高高聚物的透明度。 相似文献
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由中国石化武汉石油化工厂与华中科技大学共同研制开发的纳米阻燃聚丙烯(PP)专用料技术,日前通过了湖北省组织的技术鉴定。专家们一致认为:该技术先进合理,具有原创性,实现了阻燃与增强、增韧的集成,达到了国际先进水平,有着广阔的市场应用前景。 相似文献
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以硫酸亚锑为原料、三聚磷酸钠为分散剂,在惰性浓NaCl介质中进行沉淀反应,得到了粒径较小、分布范围较窄的纳米Sb2O3粉体. 相似文献
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通过表面吸附包覆改性,将Sb2O5胶粒从水相萃取进入非极性有机溶剂中,制备Sb2O5非极性有机溶胶.研究表明:有机胺A对Sb2O5胶粒具有改性作用;有机羧酸B能够促进TEA稳定的Sb2O5胶粒改性.通过实验得到各物质的最佳添加量如下:V(有机胺A)∶m(Sb2O5)≈1:2.22;V(有机羧酸B)∶VTEA≈4:1;采... 相似文献
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以高能球磨后的MnO2为前躯体,用水热法成功合成了平均粒径为60nm的LiMn2O4纳米微粒。实验结果表明,所合成的纳LiMn2O4在0.2℃倍率放电条件下,首次放电比容量为122mAh/g,样品在经过20次循环后容量下降约为5%左右,表现出较好的电化学性能。 相似文献
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纳米Fe3O4磁流体的制备及其性能研究 总被引:2,自引:0,他引:2
研究了化学共沉淀法制备Fe3O4纳米磁性液体的工艺过程,采用简易的方法对所制得的磁流体进行了检测和表征.对制备磁流体过程中的影响因素作了简单的分析并采用六因素四水平的正交实验对各因素进行了优化,得到了较佳的制备工艺.反应过程中保持pH值一直处于9~10之间,铁盐浓度为0.1 mol/L,其中Fe2 /Fe3 为1∶1,表面活性剂PEG4000的加入量为0.77 g(即mFe3O4/mpEG4000=1∶1),机械搅拌速率为1 000 r/min,采用机械搅拌和超声搅拌交替进行,反应温度为60 ℃并在此温度下保温陈化30 min.XRD分析表明产物微粒达到34.5 nm,采用TEM对磁流体悬浮液进行分析发现悬浮颗粒的粒径在20~40 nm之间. 相似文献
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无定形TiO2合成尖晶石Li4Ti5O12的性能 总被引:5,自引:0,他引:5
用无定形TiO2与Li2CO3高温固相反应合成了性能良好的"零应变"电极材料Li4Ti5O12. XRD, SEM和激光粒度分析表明,产物结晶度好,无杂质相,为纯立方尖晶石相,Li4Ti5O12颗粒呈砾石状形貌,有团聚现象,平均粒度约2.66 μm. Li4Ti5O12电极具有较宽的充放电平台,循环性能稳定. 以0.1 C电流比率恒电流充放电,首次放电容量和循环容量分别达180和150 mA·h/g. 交流阻抗谱研究发现,Li4Ti5O12不同嵌锂程度下的电导率对其电极的电化学阻抗具有较大影响,电极的Warburg阻抗曲线斜率与其荷电状态相关. 相似文献
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以醋酸锂和钛酸四正丁酯为原料,制备了纯相Li_4Ti_5O_(12),再用简单的水热法合成Li_4Ti_5O_(12)/Fe_3O_4复合材料作为锂离子电池的负极材料,通过XRD、SEM以及电池测试系统对纯相Li_4Ti_5O_(12)和Li_4Ti_5O_(12)/Fe_3O_4复合材料进行了结构、形貌及电化学性能测试。结果表明,制得的复合物具有较好的球形结构且粒径较小(200~300 nm),综合电化学性能较好。由于复合的Fe_3O_4有较高的理论容量,该Li_4Ti_5O_(12)/Fe_3O_4复合材料表现出比纯相Li_4Ti_5O_(12)大的容量,在1.0 C下循环100圈后,Li_4Ti_5O_(12)/Fe_3O_4的放电比容量仍能达到470.2 m A·h/g,同时也表现出比纯相Li_4Ti_5O_(12)更优的倍率性能。 相似文献
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Li4Ti5O12/C composite anode materials were synthesized by a simple starch sol assisted method using TiO2-anatase and Li2CO3 as raw materials and soluble starch as carbon source. The influences of calcination temperature and starch amounts on the microstructure and electrochemical performance were systematically investigated. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and constant-current charge/discharge cycling tests. The results showed that the Li4Ti5O12/C composite with 10 wt.% starch synthesized at 800 °C for 6 h had homogeneous particle size distribution with an average particle size of 200–300 nm and exhibited the optimal electrochemical performance with specific discharge capacities of 168.5, 160.8, 155.1 and 141.8 mAh g? 1 at 0.2 °C, 1 °C, 2 °C and 5 °C rates, respectively, and satisfactory cycling stability. It could be attributed to the homogeneous ultrafine particles and in situ carbon coating, which enhanced the electronic conductivity and diffusion of lithium ions in the electrode. 相似文献
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Yongling Ding Futian Liu Qinghui Jiang Bin Du Huadong Sun 《Journal of Inorganic and Organometallic Polymers and Materials》2013,23(2):379-384
Oriented magnetite (Fe3O4) nanorods have been successfully synthesized using a simple ethylenediamine-assisted hydrothermal technique. The samples were characterized by X-ray diffractometer, transmission electron microscopy, Fourier transform infrared and vibrating sample magnetometer. The cubic spinel structure Fe3O4 nanorods show a good crystalline state and the diameter is ~5 nm with lengths up to 0.5 μm. Experimental results indicate that ethylenediamine plays a crucial role in determining morphological features. The Fe3O4 nanorods exhibit ferromagnetic behavior at room temperature with a magnetic saturation value of 72.94 emu g?1. The growth mechanism based on the results of control experiments is also discussed. 相似文献
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以SnCl4·5H2O/C为催化剂、用乙酸和乙醇为原料,直接酯化合成乙酸乙酯.讨论了醇酸物质的量比、反应温度以及催化剂用量等因素对酯化反应的影响,得出最佳反应条件为催化剂用量为2.5g,乙醇和乙酸的物质的量比为11.5,反应温度为95℃.催化剂重复使用率好,酯的产率高达93.38%. 相似文献
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《Ceramics International》2016,42(13):14855-14861
Pure spherical Li4Ti5O12 spinel material is quickly synthesized via an efficient hydrothermal procedure. The obtained Li4Ti5O12 particle size is about 0.5 µm. The Li4Ti5O12 has an initial discharge capacity of 162.2 mA h g−1 and capacity retention of 97.5% after 100 cycles at a rate of 0.2 C. Then, a 2.5 V and long-lasting Li-ion cell with a LiMn2O4 cathode and a Li4Ti5O12 anode is developed. Electrochemical measurements of the cell indicate that the Li4Ti5O12/LiMn2O4 full cell, with a weight ratio of 1.5 between cathode and anode, exhibits excellent electrochemical performance, delivering a reversible capacity of 130 mA h g−1 at room temperature. The full cell also exhibits outstanding electrochemical performances at high temperature, as it has an initial discharge capacity of 109.6 mA h g−1, along with a capacity retention rate of 88.9% after 100 cycles at 55 °C. 相似文献
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Dan Wang Chunming Zhang Yaoyao Zhang Jin Wang Dannong He 《Ceramics International》2013,39(5):5145-5149
La-doped Li4Ti5O12 was successfully synthesized from Li2CO3, La2O3 and tetrabutyl titanate by a simple ball milling assisted modified solid-state method. The impact of La-doping on crystalline structure, particle size, morphology and electrochemical performance of Li4Ti5O12 was investigated. The samples were characterized by XRD, SEM, galvanostatically charge–discharge and electrochemical impedance spectroscopy. The results demonstrated that the in-situ coated and ball-milling method could decrease the particle size and prevent the aggregation of Li4Ti5O12. La-doping obviously improved the rate capability of Li4Ti5O12 via the generation of less electrode polarization and higher electronic conductivity. Li3.95La0.05Ti5O12 exhibited a relatively excellent rate capability and cycling stability. At the charge–discharge rate of 0.5 C and 40 C, its discharge capacities were 176.8 mAh/g and 54.7 mAh/g. After 10 cycles, fairly stable cycling performance was achieved without obvious capacity fade at 0.5 C, 1 C, 2 C, 5 C, 10 C, 20 C and 40 C. In addition, compared to Li4Ti5O12, Li3.95La0.05Ti5O12 almost did not have the initial capacity loss. It indicated that Li3.95La0.05Ti5O12 was a promising candidate material for anodes in Li-ion battery application. 相似文献
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针对Li4Ti5O12导电性和倍率性能差的缺陷,以PEG为碳源采用溶胶-凝胶法制备出电池负极材料Li4Ti5O12/C,考察不同分子量聚乙二醇PEG(400、600、1000)做碳源制备的Li4Ti5O12/C复合材料电化学性能的优劣,采用热重分析仪(TG)、X射线衍射仪(XRD)、扫描电镜(SEM)、透射电镜(TEM)、恒流充放电、倍率放电、交流阻抗(EIS)等方法对材料进行了结构表征和电化学性能测试。结果表明:以PEG1000为碳源时得到的Li4Ti5O12/C,0.1C下首次放电比容量为143.5 mA·h·g-1,2C的倍率下仍然保持了105 mA·h·g-1的比容量,容量保持率达到73.17%,并且此材料有最小的电阻,在大电流条件下有良好的电化学性能。 相似文献