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方波溶出伏安法测定镀镍液中的微量铜 总被引:4,自引:1,他引:3
为建立镀镍液中微量铜的测定方法,用方波溶出伏安法测定了镀镍液中的微量铜(Ⅱ).研究了最佳的测定条件,确立了测定方法.试验结果表明,在pH值为4.0~4.5的NH4Cl-Na2SO4底液中,Cu2 于-O.156 V(vsSCE)出现灵敏溶出峰,峰电流在铜(Ⅱ)浓度为5.0×10-7 ~1.0×10-5 mol/L时呈现良好的线性关系,回归方程Ip(μA)=1.06 1.08C(×10-6 mol/L),相关系数为0.999 4.方法的变异系数为2.7%,检出限为2.8×10-7 mol/L,回收率为94%~106%.该方法应用于现场镀镍液中微量Cu2 的测定,效果较好. 相似文献
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石墨烯修饰碳糊电极循环伏安法测定铜离子 总被引:1,自引:0,他引:1
用石墨烯修饰碳糊电极,采用循环伏安法在BR缓冲溶液中测定Cu2+的电化学行为。研究了不同条件对Cu2+电化学测定的影响。实验表明,石墨与石墨烯比例为8∶1,pH=3.5,扫描速度为100mV/s进行循环伏安法测定时,在0.136V左右处出现一个峰形较好的特征吸收峰;峰电压与Cu2+浓度在5×10-8~1×10-4 mol/L范围内呈良好的线性关系,相关系数为0.9905,检出限为5.572×10-8 mol/L;连续测定两周,电极表现出较好的稳定性。 相似文献
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采用超声法制备了三聚氰胺-甲醛-乙二胺四草酰乙酸螯合树脂(MFT)。利用MFT/纳米碳管复合物修饰充蜡石墨电极WGE(MFT/MWCNTs/WGE)制备了一种镍离子传感器。采用场发射扫描电镜及电化学等技术表征了该修饰电极的特性。结果显示,羧基化纳米碳管对MFT螯合树脂具有较强的粘合力,可使该螯合树脂有效地分散,并均匀地吸附在纳米碳管上。MFT/MWCNTs/WGE对镍离子检测效果较好,在1.0×10-11mol/L~1.0×10-10mol/L的浓度范围内,Ni(II)的溶出峰电流与其浓度呈良好的线性增长关系,其线性方程为i(μA)=9.58438+1.07753C x(1×10-11mol/L),R=0.991,检测限为1×10-13mol/L(3σ)。 相似文献
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Data are summarized on the performance characteristics and properties of Russian-produced and foreign carbon–carbon composite materials for various engineering applications. The effect of neutron irradiation on their macroscopic properties and structure is examined. The relationships between the radiation-induced dimensional changes and properties of the composites are established, which can be used in assessing the engineering performance and optimizing the fabrication of carbon–carbon composites. 相似文献
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炭/炭复合材料表面预炭层的制备及其性能研究 总被引:4,自引:1,他引:3
为在炭/炭复合材料表面制备C/SiC浓度梯度高温抗氧化涂层,预先用料浆涂刷-高温处理工艺在其表面制备了预炭层.借助XRD、Raman和SEM等测试手段对所制备预炭层的组织结构和微观形貌进行了表征,讨论了不同的原料配比和炭化温度对预炭层结构的影响,并对预炭层与基体的结合性能进行了测定.研究结果表明:制备的预炭层结构致密,与基体具有较好的结合性能,其结合强度可达10.95MPa.不同的原料配比和炭化温度影响了炭层序态结构的形成,最终形成了不同结构的预炭层. 相似文献
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《材料科学技术学报》2017,(1)
High-purity carbon nanotubes(CNTs) with different orientation and lengths were grafted on carbon fibers(CFs) in woven fabrics by using double injection chemical vapor deposition and adjusting the growth temperature.Scanning electron microscopy(SEM),transmission electron microscopy(TEM) and Raman investigations reveal that the grafted CNTs change from being predominantly aligned and uniform in diameter to absolutely disordered and variable in diameter,whilst they show significantly increased crystallinity,as the growth temperature is increased from 730 °C to 870 °C.In tensile tests of fiber bundles,much more strength degradation of CFs was observed after the growth process at higher temperature than that at lower temperature.These hybrid preforms produced at different growth temperatures were used to reinforce carbon/carbon(C/C) composites.An increment of 34.4% in out-of-plane compressive strength(OCS) was obtained for the composites containing CNTs grown at 730 °C,while the OCS increment exhibits an obvious decrease with increasing the growth temperature.Compared with the higher growth temperature,the lower temperature contributes to the decrease in the strength loss of reinforcing fibers and meanwhile the growth of large extending length of CNTs,which can provide long reinforcement to the pyrocarbon matrix,and thus increase the compressive strength better. 相似文献
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Although in-situ growing carbon nanotubes(CNTs) on carbon fibers could greatly increase the matrix-dominated mechanical properties of carbon/carbon composites(C/Cs),it always decreased the tensile strength of carbon fibers.In this work,CNTs were introduced into unidirectional carbon fiber(CF) preforms by electrophoretic deposition(EPD) and they were used to reinforce C/Cs.Effects of the content of CNTs introduced by EPD on tensile property of unidirectional C/Cs were investigated.Results demonstrated that EPD could be used as a simple and efficient method to fabricate carbon nanotube reinforced C/Cs(CNT—C/Cs) with excellent tensile strength,which pays a meaningful way to maximize the global performance of CNT—C/Cs. 相似文献
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