共查询到18条相似文献,搜索用时 140 毫秒
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纳米级铜粉的制备 总被引:44,自引:1,他引:43
研究了以CuSO4·5H2O 和NaH2PO2 为主要原料制备纳米铜粉的初步工艺:2 560 mLc(CuSO4) = 0 .0715 mol/L的溶液( 用NH3·H2O将其pH 值调到5 .0 ,含OP分散剂4 mL) 与240 mLc(NaH2PO2) = 1 .0320 mol/L的溶液反应,溶液反应前的温度为55 ~66 ℃,NaH2PO2 溶液的加入速率为80 mL/min ,搅拌强度为120 r/min 。用该工艺制备的纳米铜粉收率在90 % 以上。XRD 检测结果表明产物为单质铜;TEM 检测结果表明这种铜粉的粒径为30 ~50 nm 。 相似文献
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使用聚乙烯吡咯烷酮(PVP)和聚乙二醇(PEG)作为钝化剂对铜纳米颗粒进行原位包覆制备了PVP/PEG/Cu复合纳米粒子(CuNP),将其作为导热增强剂引入到PEG中制备了CuNP/PEG固-液相变储能材料(PCMs),并通过FTIR、XRD、DSC以及TGA等表征了CuNP/PEG固-液PCMs的结构及热性能。利用纳米粒子表面的PVP与PEG之间的氢键和空间位阻效应,以及PVP对铜核的保护作用,赋予了铜纳米粒子在PCMs中优异的分散稳定性。结果表明,CuNP的引入能够显著提高复合相变储能材料的导热能力,并能够作为晶核加速材料的结晶行为。当纳米粒子的质量分数为5%时,CuNP/PEG固-液PCMs的相变焓值为157.0 J/g,体系的储热速率、放热速率和结晶速率与纯PEG相比分别提高了34.09%、31.45%和53.33%。 相似文献
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化学法制备电极用超细铜粉 总被引:1,自引:0,他引:1
以CuSO4溶液为原料,采用NaOH沉淀-葡萄糖预还原-水合肼还原工艺(简称两步液相还原法)制得了粒度均匀可控、分散性好、适用于陶瓷电容器电极的球形超细铜粉。实验研究了葡萄糖预还原、水合肼的添加方式以及添加剂聚乙烯吡咯烷酮(PVP)和NH4Cl对超细铜粉粒度和形貌的影响。结果表明,葡萄糖预还原和水合肼的分步添加均有利于超细铜粒子的均匀生长,适量PVP的加入有助于超细铜粉粒径均匀并使其形貌趋于一致,NH4Cl可使铜粉的粒径变小,当Cu与NH4Cl的摩尔比为1∶1时铜粉的形貌会由类球形向正多面体转变。 相似文献
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以碱性蚀刻废液为原料,采用液相还原法制备了纳米铜粉,将制备的纳米铜粉作为导电填充料添加到环氧树脂中制备出纳米铜导电胶。研究了纳米二氧化硅、硅烷偶联剂KH570和纳米铜粉的添加量对导电胶剪切强度以及纳米铜粉添加量对导电胶体积电阻率的影响,探讨了环氧树脂与固化剂聚酰胺适宜的反应时间。实验结果表明,所制备的铜粉为球状,粒径在40~100nm之间;当环氧树脂与固化剂聚酰胺树脂650的质量比为4∶1,纳米二氧化硅、硅烷偶联剂和纳米铜粉的加入量分别占环氧树脂–聚酰胺树脂体系质量的1.5%、4.0%和70%时,在90°C下固化1.0h,可以制备出体积电阻率为3.05×10-3Ω·cm、剪切强度达8.04MPa的导电胶。 相似文献
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在乙醇/水的混合溶液中,采用聚乙烯吡咯烷酮(PVP)为分散剂,偶氮二异丁腈(AIBN)为引发剂,通过分散聚合法制备出聚苯乙烯(PS)微球。然后以微球为模板,PS粒子作为核,SiO_2作为壳,在600℃时经过热分解得到SiO_2空心球。通过热分析仪、扫描电子显微镜对制得的空心球进行了表征和分析,并讨论其影响因素。 相似文献
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以硫脲、九水硝酸镉为原料,乙二醇为溶剂,聚乙烯吡咯烷酮(PVP)为分散剂,聚丙烯酰胺(PAM)或N,N-二甲基甲酰胺(DMF)为生长调节剂,采用溶剂热法成功制备了硫化镉纳米材料。探究了分散剂与生长调节剂对溶剂热法合成硫化镉纳米材料的影响。研究表明,仅以PVP为分散剂制得的硫化镉颗粒呈现规则的球形且粒度均匀,小球粒径约为500 nm;以PVP为分散剂,DMF为生长调节剂,两者协同作用抑制了硫化镉的生长,得到的硫化镉颗粒粒度均匀,小球粒径约为250 nm;以PVP为分散剂,PAM为生长调节剂,两者协同作用得到的硫化镉颗粒呈现规则的球形且粒度均匀,小球粒径约为125 nm。X射线衍射(XRD)表征结果表明,合成的硫化镉是纯相硫化镉,生长调节剂具有粒径“倍增效应”。 相似文献
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Jingxian Zhang Dongliang Jiang Qingling Lin 《Journal of the American Ceramic Society》2005,88(4):1054-1056
In this paper, poly(vinyl pyrrolidone) (PVP) was selected as a dispersant for preparation of high concentrated silicon carbide (SiC) slurries in an ethanol (EtOH)/methyl ethylene ketone (MEK) solvent system. The interactions between (1) solvent and powders, (2) the solvent and dispersant, and (3) dispersant and powder were characterized in terms of adsorption and viscosity measurement. It was evidenced that the dispersion of SiC slurries was highly dependent on the solvent composition. Well-stabilized SiC slurries could be obtained using PVP as a dispersant in EtOH/MEK media with the content of EtOH in the 40–50 wt% range. The optimal dosage of PVP as a dispersant was at a PVP/SiC mass ratio of 17 mg/g. Results showed that PVP was an effective dispersant for SiC in EtOH/MEK media. 相似文献
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《Ceramics International》2016,42(3):4347-4353
A direct coagulation casting method for silicon nitride suspension via dispersant reaction was reported. Tetramethylammonium hydroxide (TMAOH) was used as dispersant to prepare silicon nitride suspension with high solid loading and low viscosity. Influences of TMAOH and pH value on the dispersion of silicon nitride powder were investigated. Glycerol diacetate (GDA) was used to coagulate the silicon nitride suspension. Influences of the concentration of glycerol diacetate on the viscosity and pH value of the suspension were investigated. It was indicated that high viscosity sufficient to coagulate the suspension was achieved by adding 1.0–2.0 vol% glycerol diacetate at 40–70 °C. The coagulation mechanism was proposed that the silicon nitride suspension was destabilized by dispersant reacting with acetic acid which was hydrolyzed from glycerol diacetate at elevated temperature. Coagulated samples could be demolded without deformation by treating 50 vol% silicon nitride suspensions with 0.2 wt% tetramethylammonium hydroxide and 1.0–2.0 vol% glycerol diacetate at different temperatures. Dense silicon nitride ceramics with relative density above 98.8% had been prepared by this method using glycerol diacetate as coagulating agent sintered by different methods. 相似文献
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利用酸性CuCl2蚀刻废液制备微米级Cu2O粉体 总被引:1,自引:0,他引:1
以含CuCl2酸性蚀刻废液为原料,葡萄糖为还原剂,采用液相还原法制备分散性好的微米级Cu2O粉. 实验确定最佳制备条件为:反应温度80℃,终点pH值8~9,反应时间1 h,还原剂和铜离子摩尔比为0.8. 所制Cu2O产品纯度为99.34%,Cu回收率可达99.7%. 进一步采用XRD, SEM, LZS, TG等手段对产物进行表征,结果表明产品为高纯Cu2O,粒径为1.8~2.2 mm,空心多面体结构,且常温下抗氧化性好,有可能用于催化剂、涂料、染料等的制备. 相似文献