| 查看: 968 | 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
288求调剂，一志愿华南理工大学071005
已经有5人回复
-
一志愿中国海洋大学，生物学，301分，求调剂
已经有5人回复
-
294求调剂材料与化工专硕
已经有12人回复
-
0856调剂，是学校就去
已经有5人回复
-
0817 化学工程 299分求调剂 有科研经历 有二区文章
已经有13人回复
-
梁成伟老师课题组欢迎你的加入
已经有11人回复
-
复试调剂
已经有6人回复
-
0703化学调剂 ，六级已过，有科研经历
已经有11人回复
-
321求调剂
已经有10人回复
-
东华理工大学化材专业26届硕士博士申请
已经有8人回复
» 抢金币啦！回帖就可以得到:
-
2026年国基求好运！
+5/340
-
绍兴大学博士教师招聘1位（化学化工相关）
+5/315
-
农业信息工程技术（专硕）招收调剂 沈阳农业大学
+1/192
-
山东征女友，坐标济南
+1/164
-
专业技术开发及第三方检测
+1/86
-
飘在美国，有点想家
+1/53
-
上海交通大学电催化方向博后招聘-有锂电、高分子、燃料电池背景者优先
+1/31
-
中科院生态环境研究中心国重实验室招聘客座研究生1-2名
+1/30
-
中山大学院士团队微纳器件、脑机接口方向博士招生、博后招聘
+1/19
-
南京林业大学木质纤维功能材料国际联合创新中心招收2026级博士生（申请-考核制）
+2/16
-
华中科技大学管理学院招聘社会用工（科研助理）1名
+1/6
-
26年申博自荐-计算机视觉
+1/6
-
211/双一流石河子大学化学化工学院--电催化，CO2转化
+1/5
-
南京理工大学招收2026级硕士生-张光普博导
+2/4
-
博后即将出站，求稳定的教职
+1/3
-
军科某研究院接收调剂研究生
+1/3
-
首次招收资格，招收工科调剂！
+1/1
-
中国科学院地球化学研究所招科研助理
+1/1
-
北京大学环境学院张子帅研究员招收科研助理
+1/1
-
西安电子科技大学团队诚聘锂电池/固态电池等方向青年教师和博士后
+1/1
4楼2011-02-12 21:53:23
2楼2011-02-12 21:33:29
3楼2011-02-12 21:34:37
5楼2011-02-13 07:57:57
