| 查看: 1025 | 回复: 7 | |||
| 本帖产生 1 个 翻译EPI ，点击这里进行查看 | |||
| 当前只显示满足指定条件的回帖，点击这里查看本话题的所有回帖 | |||
[交流]
关于化学实验的翻译求助
|
|||
|
2.1. Synthesis of cobalt ferriteCoFe2O4 (sample CFO) was synthesized by chemical coprecipitationby the following procedure. A 0.2 M solutionwas prepared by dissolving Co(NO3)26H2O (A.C.S.reagent, Aldrich) and Fe(NO3)39H2O (puriss, Fluka) in deionized water. The precipitating agent was a 5 M NaOH(reagent grade, Aldrich) solution with 100% molar excess. Both solutions were heated separately to 65 C and thenmixed under constant stirring. The temperature was raised to 80 C for 20 min, to completely crystallize the spinel phase. The precipitate was centrifuged and thoroughly washed with distilled water. The cobalt ferrite was kept in a water suspension. One small portion was dried at 80 C for characterization. 2.2. Preparation of a ferrofluid The cobalt ferrite/water suspension was heated to 80 C under gentle stirring. Oleic acid (reagent grade, Sigma– Aldrich) was added to the suspension at 30 wt.% with respect to the cobalt ferrite. The temperature was raised to 90 C for 30 min and then cooled to 60 C. Octane (reagent grade, Sigma–Aldrich) was added and the mixture was stirred for another 30 min. During this process, the nanoparticles were transferred from the aqueous phase to the organic phase, thus forming the ferrofluid. Prior to its collection, the ferrofluid was washed with distilled water in a separatory funnel to remove the non-modified particles. A gravimetric study of a 2.5 g aliquot was carried out to determine the content of inorganic material in the ferrofluid by weight difference before and after calcination at 700 C. A sample of the surface-modified ferrite was reserved before the addition of octane to determine the amount of oleic acid that reacted with the particles. The sample was dried at 80 C before performing a thermogravimetric analysis on a TGA Q500 by TA Instruments, from room temperature to 700 C at 5 min1. 2.3. Synthesis of cobalt ferrite–barium titanate core–shelltype nanostructures Core–shell-like nanostructures of CoFe2O4–BaTiO3 were synthesized by the sol–gel technique. Ba(C2H3O2)2 (A.C.S. reagent, Sigma–Aldrich) was mixed with titanium (IV) n-butoxide (reagent grade, Sigma–Aldrich), stearic acid (95%, Sigma–Aldrich) and glacial acetic acid (Aldrich) at 90 C to form a sol. The ferrofluid was added to the sol at an adequate amount so that the final nanostructures have a content of 20, 30, 40, 50 and 60 wt.% of cobalt ferrite with respect to the barium titanate, namely samples Co20, Co30, Co40, Co50 and Co60, respectively. Anhydrous 2-methoxyethanol (Aldrich) was added to promote the gel formation. The obtained gels were dried overnight at 80 C and sintered at 700 C for 2 h under the following conditions: (a) heating rate of 1.8 C min1 from room temperature to 350 C; (b) heating rate of 1.5 C min1 from 350 C to 700 C and (c) cooling rate of 4 C min1 from 700 C to room temperature, to avoid cracking of the barium titanate, which is the shell in the nanostructures and is expected to be subjected to high stresses. One additional sample without ferrofluid was also prepared as a reference (sample BTO). All samples were washed with a 0.1 M acetic acid solution to dissolve impurities such as barium carbonate [18]. We note that if the stearic acid, glacial acetic acid and 2-methoxyethanol were omitted from the preparation, the resulting material consisted of a simple mixture of individual cobalt ferrite and barium titanate nanoparticles. |
回复此楼» 猜你喜欢
材料专硕(0856) 339分求调剂
已经有4人回复
-
一志愿华工085600 331分
已经有3人回复
-
268分085602化学工程调剂
已经有4人回复
-
一志愿中科院105500专业总分315求调剂
已经有3人回复
-
材料299专硕求调剂
已经有6人回复
-
086004 求调剂 309
已经有6人回复
-
280求调剂
已经有3人回复
-
085400 328分 求调剂
已经有7人回复
-
材料专硕322
已经有12人回复
-
一志愿华中农微生物，288分，三年实验经历
已经有3人回复
» 抢金币啦！回帖就可以得到:
-
★★热帖★★0860生物与医药调剂考生看过来，河北大学化学与材料科学学院
+2/188
-
重庆长江师范学院材料工程方向接收材料类和机械类考生调剂硕士研究生
+1/145
-
淮北师范大学资源与环境硕士研究生调剂名额充足（26人），欢迎调剂。
+2/132
-
上海交通大学化学化工学院膜分离-纳流控课题组诚聘博士后2-3名
+1/88
-
杭州师范大学张龙课题组招诚聘有机合成，光电催化，理论计算与人工智能化学方向博士后
+1/85
-
招收化学、海洋科学、材料、环境专业调剂
+3/67
-
26申博自荐（新能源电池方向）
+1/41
-
2026年招化学、材料、化工等专业调剂硕士生！初试可不考数学！
+1/21
-
上海应用技术大学姚子建课题组招生，点击就送研究生学历
+1/20
-
杭州医学院张逢质教授课题组招收药学硕士研究生若干
+1/19
-
华南师范大学光电科学与工程学院魏嵬课题组招收硕士调剂生
+1/13
-
贵州铜仁学院研究生招生
+1/12
-
重庆工商大学 教育部研究中心招收化工/环境/材料/石油/机械方向2026年调剂研究生
+1/11
-
大连大学 化学专业 招收26年硕士研究生调剂
+1/11
-
湖南理工大学调剂系统已开。 化学、化工、材料化工 调剂指标充足，录取率高，欢迎调剂
+1/10
-
山东大学谢玉生课题组-诚聘博士后/科研助理（长期有效）
+1/8
-
齐齐哈尔大学李莉课题组诚招2026级考研调剂生（学硕和专硕）
+1/6
-
2026年西华大学材料学院-材料近净成形与表面技术研究团队-招收调剂研究生
+1/5
-
河北大学招收等离子体物理调剂生
+1/2
-
河北农业大学 招收化工材料类调剂生，联系微信18632728096 非诚勿扰。
+1/1
|
其实主要只有一段话不明白，During this process, the nanoparticles were transferred from the aqueous phase to the organic phase, thus forming the ferrofluid. Prior to its collection, the ferrofluid was washed with distilled water in a separatory funnel to remove the non-modified particles. Prior to its collection不知道指的是什么，前后的逻辑关系不是很明白，其他的我还是能看明白的。第一次求助翻译，不知道多少金币翻译多少字合适，我想既然求助了，就粘过来了 |
7楼2011-02-13 09:24:55
2楼2011-02-12 21:33:29
3楼2011-02-12 21:34:37
4楼2011-02-12 21:53:23
