【作者】 倪颂；

【导师】 陈振华； 陈鼎；

【作者基本信息】 湖南大学 ， 材料加工工程， 2008， 硕士

【摘要】 利用机械力化学原理,通过高能行星球磨机,在蒸馏水中球磨金属活动顺序表中排在氢以前的金属粉末(Zn、Mn等)可直接制备相应的纳米级氧化物,并得到副产物氢气。而关于排在氢以后的金属在水溶液中球磨的现象及规律尚无研究。本文以排在氢之后的铜为实验对象,研究Cu-H2O二元系以及Cu-Cl-H2O三元系反应球磨的现象及规律,并通过XRD、SEM及TEM等分析手段分析产物特征。实验得到了如下结果:(1) Cu在纯蒸馏水中球磨时,Cu与溶解于水中的氧气反应生成Cu2O,但因罐中氧气量及溶解在水中的氧气量有限因而所得Cu2O的量有限。在机械合金化结果中,Cu粉与干燥空气中的氧气反应较难发生,因而在球磨110h后也仅得到极少量Cu2O,较水溶液条件下的量少。(2) Cu在蒸馏水中球磨,当体系氧压较高时(充氧条件下),Cu粉与氧气之间的反应被不断激发。由于体系氧气充足,Cu粉能被完全氧化为CuO。球磨110h后所得纯的CuO粉末较为均匀,颗粒尺寸分布在100-200nm之间。(3)在pH=2的HCl溶液中球磨金属Cu粉,球磨3h后快速得到了大量的Cu2O粉末,但同时含有少量Cu2(OH)3Cl和CuCl。球磨70h后得到纯度较高的Cu2O粉末,未检测到其它物相。所得Cu2O颗粒尺寸均为50-100nm之间,球磨70h所得Cu2O颗粒尺寸较球磨3h时的略小。(4)在CuCl2溶液中球磨纯铜粉末,当[Cl-]=1.5×10-2mol/L和7.5×10-2mol/L时,分别球磨25h和80h后得到完全的Cu2O,颗粒多为规则的立方状、六方状,尺寸约为50-150nm;在[Cl-]=0.3mol/L时,得到纯Cu2O粉末所需时间为100h,颗粒尺寸明显偏大且出现大量不规则形貌;在[Cl-]=0.75×10-2mol/L以及0.3×10-2mol/L时,体系较难在某一时段得到纯的Cu2O。由此可知,不同氯离子浓度将影响球磨各阶段反应、得到纯的Cu2O所需时间及所得Cu2O的颗粒大小和形貌。(5)将CuCl在水溶液中球磨,球磨80h后得到绝大多数的Cu2O。所得Cu2O颗粒大多为不规则形貌,有部分立方状及六方状颗粒,尺寸为20-80nm。更多还原

【Abstract】 Based on the principle of mechanochemistry, nanosized oxides and H2 as the side product can be obtained by ball milling metal powders (Zn, Mn etc.) in water solution using high-energy ball mill. The metal powders used rank before H in the list of metal activity sequence. However, the study on ball milling metal powders which rank after H in water solution is not available. The Cu powder which ranks after H was selected as the raw material in this experiment to study the phenomenon and principles of Cu-H2O binary and Cu-Cl-H2O trinary reaction ball milling. XRD、SEM and TEM were employed to examine the phase composition、microstructure of the final products. The experimental results were as follows:(1) By ball milling Cu powder in pure distilled water solution, Cu2O was formed by the reaction between Cu and oxygen which was dissolved in water. But the amount of Cu2O was quite limited due to the limited amount of oxygen in the ball milling system. While in the results of mechanical alloying, the reaction between Cu and oxygen was hard to occur, little amount of Cu2O was gained after 110h ball milling, which was less than in the former experiment.(2) By ball milling Cu powder in distilled water solution with a high oxygen pressure, the reaction between Cu powder and oxygen would be activated continuously. The Cu powder can be oxidized to CuO completely due to the sufficient oxygen in system. The pure CuO obtained after 110h ball milling was uniform with the particle size of 100-200nm.(3) By ball milling Cu powder in HCl solution with pH value of 2, a large amount of Cu2O was obtained after 3h milling, together with a little amount of Cu2(OH)3Cl and CuCl. While high purity Cu2O was formed after 70h milling. No other phases were examined. The particle size of Cu2O was 50-100nm.(4) Ball milling Cu powder in CuCl2 solution with [Cl-] of 1.5×10-2mol/L and 7.5×10-2mol/L, complete Cu2O were gained after 25h and 80h milling respectively. Most of the particles were cubic or hexagonal in shape and 50-150nm in size. When the [Cl-] was adjusted to 0.3mol/L, the milling time needed for forming pure Cu2O was 100h. And the particles were apparently larger in size and more abnormal in shape than the former results. When the [Cl-] reached 0.75×10-2mol/L and 0.3×10-2mol/L, pure Cu2O was hard to form in a certain period. It can be concluded that different concentration of Chloride ion would affect the reactions in different milling periods, the needed time for forming pure Cu2O and the size、shape of Cu2O particles.(5) A large amount of Cu2O was obtained after 80h ball milling CuCl in water solution. Most of the Cu2O particles were abnomal in shape and 20-80nm in size. There were also partial particles of cubic and hexagonal shapes.更多还原