| 查看: 754 | 回复: 3 | |||
| 当前主题已经存档。 | |||
| 本帖产生 1 个 翻译EPI ，点击这里进行查看 | |||
szxxck木虫 (正式写手)
|
[交流]
重金求助高人翻译一段摘要（非Google或翻译软件翻译）
|
||
|
本文合成了一系列阳离子氟表面活性剂, N-[3-(二甲基胺基)丙基]全氟烷基磺酰胺盐酸盐(CnF2n+1SO2NH(CH2)3NH(CH3)2+Cl–, n = 6, 8, 分别简称为PFH-MC和PFO-MC), 并用滴体积法测定25 ◦C、pH 2.6~2.7时该类物质的单体系及加盐后([NaCl] = 0.1 mol•L-1)的表面张力曲线。结合上述PFB-MC的结果讨论分子结构中碳氟片断的链长对水溶液中表面活性的影响。对比胶团形成能力、降低表面张力的能力、表面吸附状况和酸性条件的强弱影响表面活性剂适用情况的结果表明以下结论。首先，随着链长的增加临界胶束浓度(cmc)减小但表面吸附量降低(单分子吸附面积增大)；单体系最低表面张力(γcmc)PFH-MC最小(15.02 mN•m-1)，PFO-MC的γcmc和PFH-MC相比略有上升可理解为长链表面活性剂的溶解性的限制或者空间排列的影响。外加盐能降低体系的cmc（这可以通过增加碳链的疏溶剂性质来解释）但由于盐酸过量溶液中相当于已经存在一定量的电解质来屏蔽头基电荷的排斥导致对γcmc未观察到影响。讨论了链长变化对盐效应的影响，这种影响呈现不规则的变化，PFH-MC所受的盐效应从某种程度表现最明显。这可能是由于碳链长度PFH-MC最适中，而PFO-MC和PFB-MC过长、过短的碳链即疏水性较大或较小都使得外加NaCl带来的疏溶剂效应减小。研究了表面活性剂在cmc前后的表面张力随pH的变化。 本文研究证明了该系列以全氟烷基为基础的、含有碳氢片段的阳离子型氟表面活性剂适用于强酸性环境、抗盐、且具有极高的表面活性，我们对实际选择进行了综合评价：该类表面活性剂适用于强酸性环境并且不易受盐度环境的干扰。加盐还能明显改善表面活性剂的性能、降低该表面活性剂的cmc。综合评定链长的影响可知，根据使用情况不同，如果对超低表面张力要求严格，可选用氟碳数为6的PFH-MC(最低表面张力显著低于PFB-MC)，它无论从浓度(cmc和PFO-MC相差不是特别大，使用时所需量小)还是使用的性价比(碳氟链短，生产成本优于PFO-MC)考虑都是优化的；如果考虑到环境保护和生物降解的要求而对最低表面张力的要求适当放松，可选用PFB-MC。 |
回复此楼» 猜你喜欢
318求调剂
已经有8人回复
-
求调剂
已经有7人回复
-
0703化学
已经有13人回复
-
307分材料专业求调剂
已经有4人回复
-
0855求调剂材料
已经有8人回复
-
332求调剂
已经有9人回复
-
甲醇/二氯 1:15过柱子
已经有3人回复
-
272求调剂
已经有4人回复
-
一志愿西北农林畜牧专硕336分求调剂
已经有3人回复
-
求调剂
已经有10人回复
pharmjackie
木虫 (正式写手)
- 翻译EPI: 21
- 应助: 2 (幼儿园)
- 金币: 2210
- 帖子: 312
- 在线: 180.4小时
- 虫号: 302356
- 注册: 2006-12-02
- 性别: GG
- 专业: 有机合成
szxxck(金币+50):谢谢！专有名词我已经改了。 2010-03-29 22:34
| A series of cation fluoride surfactant, N-[3-(dimethylamino)propyl]perfluoroalkylsulfonamides hydrochloride (CnF2n+1SO2NH(CH2)3NH(CH3)2+Cl–, n = 6, 8 (hereafter referred to as PFH-MC and PFO-MC respectively) had been synthesized. The surface tension curve had been plotted using volume-titration method at a pH of 2.6~2.7 at 25 ◦C for the compound alone and for the system with a salt concentration of 0.1mol/L. The influence the chain length of C-F moiety had on the surface activity of the aqueous solution was discussed with the above results. Comparison of the ability to form micelle, the ability to reduce surface tension, absorbtion state on the surface and the influence acidity had on the application of the surfactant showed that CMC decreased with increasing chain length, with a decreasing absorption capacity due to per-molecular increasing absorption area. The compound alone showed a minimum surface tension, (ycmc)PFH-MC, 15.02 mN/m, while a slight higher surface tension was observed for PFO-MC might be contributed to the solvate limitation that long-chain surfactant had and the steric influence. Additional salt can lower the CMC of the system, which can be explained by its ability to increasing solventphobic forces, but no significant effect had been observed for ycmc because excess hydrochloric acid in the solution might serve as electrolyte to shield capitular charge exclusion forces. The influences chain length had on salt effect was also discussed, which showed irregular alterations with PFH-MC exhibited the most strong salt effect. It might be due to a moderate chain length that PFH-MC had but PFO-MC and PFB-MC had a over-long or over-short chain, i.e. too strong or too weak hydrophobic forces could reduce the hydrophobic effect that additional salt might bring. We also studied how the surfactant’s activity changed with pH. |
2楼2010-03-29 20:02:18
pharmjackie
木虫 (正式写手)
- 翻译EPI: 21
- 应助: 2 (幼儿园)
- 金币: 2210
- 帖子: 312
- 在线: 180.4小时
- 虫号: 302356
- 注册: 2006-12-02
- 性别: GG
- 专业: 有机合成
3楼2010-03-29 20:04:20
pharmjackie
木虫 (正式写手)
- 翻译EPI: 21
- 应助: 2 (幼儿园)
- 金币: 2210
- 帖子: 312
- 在线: 180.4小时
- 虫号: 302356
- 注册: 2006-12-02
- 性别: GG
- 专业: 有机合成
szxxck(金币+50, 翻译EPI+1):谢谢！ 2010-04-18 17:15
| The results showed that this series of perfluoroalkyl cationic fluoride surfacetant is applicable to strong acid conditions, resistant to salt and with high surfaceactivity. (此后一句我给省了，同前一句基本是同意)。 Addition of salt could improve the surfactant’s performance significantly, reducing the CMC of the surfactant. Taking the chain length influences into consideration, the six F-C numbered PFH-MC is the first choice with a comparable CMC with PFO-MC but a lower dose, and lower produce-cost than PFO-MC due to shorted C-F chain, while PFB-MC is the best choice when environment-protection and bio-degrade is taken into account. |
4楼2010-03-29 20:19:19
