| 查看: 2408 | 回复: 4 | ||
| 本帖产生 1 个 翻译EPI ，点击这里进行查看 | ||
cpy1239860银虫 (小有名气)
|
[求助]
求600字翻译，高悬赏，急用啊，谢谢各位大哥大姐啦
|
|
|
金刚石微粉密度大，纳米级颗粒易于团聚，微米级较大颗粒易于沉降，致使整个研磨液体系均匀性较差，影响抛光的质量和效率。目前对纳米金刚石悬浮液的研究非常多，但纳米金刚石的粒径限定范围比较窄，应用范围有限，而实际生产中对微米金刚石悬浮液的需求也很广，但是对微米级的金刚石的研究很少涉及。 本文研究了金刚石微粉在水性分散体系中的分散性能，以沉降实验、Zeta电位测定为评价指标，研究了PH值、分散剂的种类与用量及分散工艺条件对分散稳定性的影响。实验表明：在水性分散体系中，悬浮液的PH值是影响其分散稳定性能的重要因素，主要影响粒子的表面电荷状态；金刚石微粉悬浮液中颗粒的等电点PH(I.P.C)=5.4而且粉体表面的Zeta电位绝对值在碱性区比在酸性区普遍要高得多，一般适宜PH值为8-10；小分子分散剂可以起到一定的分散作用，但对悬浮稳定性不于高聚物分散剂和非离子型表面活性剂。同时实验表明选择多种不同分散机理的分散试剂相复合分散效果要优于单独使用某一分散试剂时的分散效果。实验得到的经过海藻酸钠、D540分散剂 、TH-613分散剂和PVA的复配分散剂为分散剂制备金刚石悬浮液复配的分散剂分散效果最佳，静置一周后上层的澄清体积为10%。 本文采用粗化处理和偶联剂包覆改性对金刚石微粉进行表面处理，通过红外光谱分析和粉体润湿性测试表明静压法合成的金刚石表面不含含氧官能团，水溶性钛酸酯偶联剂YB401包覆在金刚石表面形成单层油膜，从而实现表面有机化，使金刚石颗粒与水的亲和性变差，呈现明显的疏水亲油性能。采用YB401偶联处理后的金刚石微粉制备的悬浮液30天后澄清体积仅为3%，同时通过陈化实验表明悬浮液的分散稳定性变差与悬浮液PH值的而变化和粉体表面的Zeta电位的变化有关，而采用钛酸酯偶联剂 处理可以减缓这个变化，其更深层次的原因还有待进一步的研究。 [ Last edited by cpy1239860 on 2011-11-18 at 17:09 ] |
回复此楼» 猜你喜欢
299求调剂
已经有5人回复
-
收复试调剂生
已经有3人回复
-
280求调剂
已经有7人回复
-
环境领域全国重点实验室招收博士1-2名
已经有5人回复
-
303求调剂
已经有6人回复
-
290求调剂
已经有10人回复
-
0703化学求调剂 总分331
已经有3人回复
-
一志愿天津大学化学工艺专业（081702）315分求调剂
已经有8人回复
-
0703化学调剂
已经有3人回复
-
材料，纺织，生物（0856、0710），化学招生啦
已经有9人回复
cpy1239860
银虫 (小有名气)
- 应助: 0 (幼儿园)
- 金币: 365.6
- 散金: 4
- 红花: 1
- 帖子: 65
- 在线: 23.8小时
- 虫号: 1132817
- 注册: 2010-10-27
- 性别: GG
- 专业: 聚合物共混与复合材料
2楼2011-11-22 09:48:22
fanliang1389
荣誉版主 (文坛精英)
有爱的二哥
- 翻译EPI: 57
- 应助: 18 (小学生)
- 贵宾: 1.989
- 金币: 13044.6
- 散金: 18540
- 红花: 123
- 沙发: 243
- 帖子: 18237
- 在线: 2429.4小时
- 虫号: 620773
- 注册: 2008-10-09
- 性别: GG
- 专业: 食品加工学基础
- 管辖: 博后之家
3楼2011-11-23 10:45:45
songe0310
木虫 (著名写手)
傻~傻得没得说的~
- 翻译EPI: 17
- 应助: 2 (幼儿园)
- 贵宾: 0.178
- 金币: 3440.8
- 散金: 2423
- 红花: 31
- 沙发: 16
- 帖子: 2135
- 在线: 741.7小时
- 虫号: 319255
- 注册: 2007-03-07
- 性别: MM
- 专业: 中药制剂
【答案】应助回帖
★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ...
爱与雨下(金币+3): 2011-11-23 15:57:07
sltmac(金币+50): 2011-11-25 09:30:09
sltmac(金币+50): 2011-11-25 09:30:12
sltmac(金币+50): 2011-11-25 09:30:16
sltmac(翻译EPI+1): 欢迎常来本版交流~ 2011-11-25 09:30:24
爱与雨下(金币+3): 2011-11-23 15:57:07
sltmac(金币+50): 2011-11-25 09:30:09
sltmac(金币+50): 2011-11-25 09:30:12
sltmac(金币+50): 2011-11-25 09:30:16
sltmac(翻译EPI+1): 欢迎常来本版交流~ 2011-11-25 09:30:24
|
As large diamond powder density, nano-particles ease to reunion and larger micro-sized particles easy to settle, which led to a poor uniformity of slurry system, thereby affecting the quality and efficiency of polishing. Currently, there has been an extensive research on nano-diamond suspension. However, as its relatively narrow scope of particle size, its application is limited. Although in actual production, the demand for micron diamond suspension is very broad, the research for it is rare. In this paper, we take settlement experiment, Zeta potential measurement as the evaluation indexes to study the dispersion of diamond powder in aqueous dispersion, and study the effects of PH value, type and amount of dispersant, dispersion processing conditions on its dispersion stability. The results show that: in aqueous dispersion, an important factor that affects the suspension’s dispersion stability is its PH value, which mainly affects the surface charge of its particles. In diamond powder suspension, the isoelectric point of its particles is PH (IPC) = 5.4. Generally, on the surface of powder, the absolute value of Zeta potential in alkaline region is much higher than that in acidic region with the appropriate PH value between 8 to 10. Small molecule can play as a dispersing agent, but its suspension stability is more poor completed with polymer dispersant and non-ionic surfactant. The results also show that the dispersion of a blend that containing dispersing agents with different dispersing mechanism is superior to a single one. Taking a blend of sodium alginate, dispersant-D540, dispersant TH-613 and PVA as dispersant, we prepared a kind of diamond suspension with the best dispersing effect, whose upper clarify volume accounts for 10 percent after resting for a week. In this paper, through coarsening processing and coupling agent-coated modification of diamond powder on the surface, and the analysis of infrared spectroscopy and wettability powder test, we concluded that the surface of the diamond, synthesized by static pressure method, does not contain oxygen-containing groups; YB401, a water-soluble titanate coupling agent, is coated on the diamond surface, and then formed a single layer oil film, thus fulfilling the surface organic and making the affinity of diamond particles and water becomes worse, showing a clear hydrophobic lipophilic property. The clarify volume of diamond powder suspension is only 3 percent in 30 days after the process of YB401 coupling. The results of aging experiment show that: changes in its PH value and surface Zeta potential contribute to the poor dispersion stability, whereas some treatment can slow the changes by using titanate coupling agents. However, deeper reason still needs further research. |
4楼2011-11-23 14:24:57
aardwolf1986
木虫 (正式写手)
- 翻译EPI: 1
- 应助: 2 (幼儿园)
- 金币: 3294.4
- 散金: 424
- 红花: 2
- 帖子: 455
- 在线: 108.9小时
- 虫号: 943926
- 注册: 2010-01-17
- 性别: GG
- 专业: 工程热物理与能源利用
5楼2011-11-23 15:05:35
