S*****n
发帖数: 6055 | 1 我楼上环境系的哥们用Toluene擦地板。。。你说美国这环境专业的学生化学课居然不
是必修，怪不得学生这么烂。。。 |
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m*****l
发帖数: 1292 | 2 Now i know why I got so depressed.
How about benzene? I am going to do a reaction that needs benzene in the
work-up. I used toluene instead,
but didn't get a good result. My boss was mad at me, and asked me to repeat
the work-up with benzene.
Where should I dump it after? To the regular organic liquid waste or some
special container? |
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c******0
发帖数: 54 | 3 add toluene, rotvap , repeat it for three times. No DMF left |
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K****N
发帖数: 10783 | 4 dmf估计可以
也可以试ethyl acetate, thf, dioxane, dcm, toluene， ether等，或者混合溶剂 |
|
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z****r
发帖数: 245 | 6 买的HPLC级别的toluene,标的水含量<0.006%，可是还是对反应有影响。请教怎么样才
能除去这些微量水啊？蒸馏还管用么？ |
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z****r
发帖数: 245 | 7 化学不太懂，让超工见笑了。我们是用到了MgO纳米颗粒做support,用Aldrich的
toluene来分散，可是总是发现之后MgO形状结构都变了，能想到的只有水会跟它反应了
。其实算了一下这点水应该没啥大影响，可是事实硬生生就是这样滴，怀疑碰到奸商了。
李老大的建议不错，安全一些，马上来试试。另外还有细节问题请教，见站内信箱。 |
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l*****n
发帖数: 1 | 8 本人略知一点日语，翻译以下仅供参考。
60分钟反应, 直到没有反应的C3H5ClO （Epichiorohydrin） 完全消失，ethyl-
Epichiorohydrin生成，在生成的-ethyl –Epichiorohydrin 中加入2960 g toluene. |
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f***o
发帖数: 161 | 9 DIBAL-H in toluene should give better selectivity than DIBAL-H in DCM.
|
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c*********d
发帖数: 33 | 10 You can run GCMS to see if it is inside. |
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o*v
发帖数: 371 | 11 现在需要一种溶剂可以溶掉一种polyfluorene copolymer, 又不会溶掉一种两边头带
phenyl group的小分子。已经试了toluene, chloroform, xylene，都不太理想，小分
子总会或多或少的溶掉一些。各位大拿能不能推荐一种可能的溶剂啊？ |
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a**********e
发帖数: 418 | 12 可以试一下 toluene/diisopropyl amine (1:1 as a solvent) for Sonagashira
Coupling.
GOOD LUCK! |
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a**********e
发帖数: 418 | 13 add toluene coevaporate with rotavap until most alcohols are gone. then wash
with hexanes and dry up. |
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f*********y
发帖数: 536 | 14 很早以前的一个面试题，懂行的来讲讲。
Question 6: You are asked to developed methods for the quantitative analysis
of these volatile organic compounds. For each of the compounds listed
below, briefly describe your proposed method for analysis, including sample
collection, analytical instrumentation, detection method, and QC protocols.
(15 points)
a) toluene
b) ethanol
c) formaldehyde
1. Please explain the difference between a quality control process and a
quality assurance process. |
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n******r
发帖数: 718 | 15 Almost all gasoline sold in the US is required by law to add 6-10% ethanol.
Diesel(including biodiesel) sold in in the US is almost purely hydrocarbons
.
There is winter gasoline and there is summer gasoline, while the diesel you
buy at different seasons is the same.
Some specialized gasoline has about 50% toluene to boost octane number and
performance.
:-)
reduce
diesel |
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d******y
发帖数: 121 | 16 我实验室里面有一个这个玩意（貌似还挺贵），只是我的反应量比较小，总共只加不到
100mg。最后那粉末就就用点儿toluene配成slurry用cannula transfer了…… |
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u**********a
发帖数: 50 | 17 现有两个配合物是正离子，couterion是OTf，文献上一般这种配合物用的是CH3CN/Et2O
体系，但这两个配合物在这个体系里结晶会被氧化分解，怀疑是乙醚遇到空气后的过氧
化物跟它们反应。
我会尝试在N2保护下结晶，但目前想了解一下如果在空气里面操作还有什么比较好的溶
剂体系可以尝试？
CH2Cl2/pentane or EtOAc or toluene这三个体系都试了但是得到的都是几坨很大的花
，看起来也很难切下来做单晶衍射。这种情况下是必须把CH2Cl2换成别的溶剂还是可以
不换溶剂而只调整浓度？
谢谢！ |
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y********4
发帖数: 33 | 18 【作者】:
Ming-Qiang Zhu, Emmanuel Chang, Jiantang Suna and Rebekah A. Drezek*
【文题】:
Surface modification and functionalization of semiconductor quantum dots
through
reactive coating of silanes in toluene
【期刊名，年份，卷，起止页码】:
J. Mater. Chem., 2007,17, 800-805
【链接】:
http://pubs.rsc.org/en/Content/ArticleLanding/2007/JM/b614432b
【求助者email】:
j********[email protected]
【求助者是否发包子】:
Thanks! |
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e******d
发帖数: 310 | 19 【 以下文字转载自 Living 讨论区 】
发信人: easyroad (pine), 信区: Living
标 题: 房子边上的 电厂
发信站: BBS 未名空间站 (Thu Dec 26 20:10:05 2013, 美东)
刚搬进来两个星期， 发现房子的正东面大约2 mile的地方有个 combined-cycle gas
-fired power plant。
现在的问题是这样的房子是 污染会不会比较严重， 不适合有小孩和老人的家庭住了,
更不适合在这样的环境下怀孕了？
在网上查了下这家发电厂的基本情况，功率是800MW。 污染物的排放如下
氧化氮 （NOx）10.6 吨每年
一氧化碳 2.29 吨每年
二氧化硫 0.70 吨每年
VOC 0.87 吨每年
TSP=PM10 0.75 吨每年
Ammonia 293 吨每年
Sulfuric acid 1.621 吨每年
1，3-Butadiene 0.011 吨每年
Acetaldehyde 1.02 吨每年
Acrolein 0.163 吨... 阅读全帖 |
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q****i
发帖数: 6923 | 20 Formation of Single-Phase Microemulsions in Toluene/Water/Nonionic
Surfactant Systems
Albert J. Gotch Gary W. Loar Aaron J. Reeder Ellen E. Glista
Langmuir, 2008, 24 (9), pp 4485–4493 |
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s*******d
发帖数: 56 | 21 我有一个朋友在国内做化工园区重点污染源在线监控体系研究。他想知道美国目前是否
对化工企业或园区的污染源进行了在线监控？是否选取了特征污染物？
我是个外行，有人知道吗？或者到哪里去找到答案那？ 非常感谢。
该系统包括特征污染物的在线监测、风险源监控点信息采集、信息监控点本地储存、信
息初步可靠性分析、信息无线和/或有线传输、信息远程监控中心储存，对获得的重点
环境风险源监控点的数据进行储存和实时处理，对风险源监控点的风险程度进行预警，
并将风险源的位置、监控点的位置等信息提供给监控部门，利用GIS空间分析技术分析
风险源周边的环境状况和居民、学校等敏感受体的分布，为监督管理部门制定应急预案
、指挥应急提供技术支持。
特征污染物的翻译：苯系物（苯benzene、甲苯toluene、二甲苯dimethylbenzene）、
取代苯（硝基苯nitrobenzene、氯苯chlorobenzene、苯胺aniline）、氯酚
chlorophenol、卤代烃halogenated hydrocarbon、烷烃alkyl hydrocarbon、多环芳烃
PolycyclicAromaticHyd |
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w******z
发帖数: 29 | 22 来自主题: Macromolecules版 - 问个问题 为什么 Poly(methyl acrylate)溶解在toluene 里 when i want to buy some from
Aldrich? |
|
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w********h
发帖数: 12367 | 24 no...
there is difference between non-solvent and no-good solvent.
generally no-good solvent means theta-solvent.
as to PS, methylcyclohexane is a theta-solvent while toluene is a good one. |
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w******r
发帖数: 43 | 25 I have this blend. I want to get the PB-PEO diblock.
I tried the toluene/methonal system. It did not work.
The old way is using hexane dissolve PB and seperate the diblock
by centrifuge. I donot like this method, because it is time consuming.
Does anybody has any new ideas?
We can discuss it.
Thanks |
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w********h
发帖数: 12367 | 26 我的低分子量的PBD(Mw=2K)GPC结果显示含有少量高分子量的东西（分子量大约60K)，
如何除去？我只要一点点纯的2K（大约0.5g)就可以了.过柱子这种方法就算了，我
等不及，最好是什么不同溶剂分几次的方法。什么溶剂比较好呢？toluene+环己烷？ |
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w********h
发帖数: 12367 | 27 hoho...I in deed have three smaples from his kind help.
others are from Goodyear company...
those samples are really monodisperse and pure..
only one old sample is not so pure,
just because it is old.
now I am trying this method:
put the polymer in toluene at a concentration of 1%,
then drop ethanol slowly without any stir,
let it stay for one night,
tomorrow I just transfer the upper part of the solution to another beaker,
drop ethanol slowly again.....
evaporate at last.
it should get rid of t |
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b**s
发帖数: 589 | 28 Poly(vinyl acetate)
Catalog # : 347
CAS : 9003-20-7
Physical Form : Pellets
Approx Mw : 100,000
Density (g/cc) : 1.18
Refractive Index : 1.4665
Inherent viscosity : 0.42
Softening Point (C) : 97
TSCA : TSCA listed
Tg (C) : 30
Soluble in : Acetone, benzene, butyl acetate, carbon tetrachloride,
chloroform, dichloroethylene, ethanol, ethyl acetate, methanol, MIBK, THF,
toluene |
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f**********e
发帖数: 16 | 29 What's the normal way in lab? I know in industry people use hot THF or toluene
or xylene to dissolve PE copolymer, but not sure about the exact procedure. I
have this blend with small amount of PP and the PE matrix. My purpose is to
dissolve PE and leave the PP which is highly oriented. Thanks a lot! |
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w********h
发帖数: 12367 | 30 刚巧看到一段怎样纯化PEG:
PEGs (aldrich) were dried by an azeotropic distillation in toluene and then
evacuated under reduced pressure to remove residual traces of water. |
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p*****d
发帖数: 40 | 31 r u kidding? you must be a math major or you are from Mar...
try CHCl3, THF, toluene.... |
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w***o
发帖数: 3830 | 32 u buy it in toluene solution from aldrich
with a wt% of aluminia |
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r***o
发帖数: 35 | 33 看到不同的paper用不同的条件，都是用toluene，但是有的在室温，有的在升高温度下溶
胀，到底有没有标准的方法呢？ |
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f**********f
发帖数: 155 | 34 got a question when reading a paper:
"After polystryene/toluene spin-coat, it was dried for 4 days at 70 C".
Why it needs such a long baking time, any particular reasons?
A beginner for polymer, thanks for helping out. |
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c****n
发帖数: 134 | 35 To get out most (if not all) residual toluene. It's probably under vacuum. |
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m*******e
发帖数: 119 | 36 MIBK has low surface energy (24 dyne/cm). Toluene is about 28, similar to
xylene. They have meidum boiling points and vapor pressure. Low boiling
point and high vapor pressure allow the solvent to evaporate very quickly,
which may help to reduce crystalization effect in your film. But the problem
is that you might not be able to get nice uniform film due to high
evaporation rate. You can check other solvents that you can find. The
physical properties of the solvents can be found from Belstein da |
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m*******e
发帖数: 119 | 37 MIBK has low surface energy (24 dyne/cm). Toluene is about 28, similar to
xylene. They have meidum boiling points and vapor pressure. Low boiling
point and high vapor pressure allow the solvent to evaporate very quickly,
which may help to reduce crystalization effect in your film. But the problem
is that you might not be able to get nice uniform film due to high
evaporation rate. You can check other solvents that you can find. The
physical properties of the solvents can be found from Belstein da |
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m*******e
发帖数: 119 | 38 If possible, try toluene or MIBK (methyl isobutyl ketone) |
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s*****i
发帖数: 146 | 39 I synthesized PLA-PEG-PLA (2.5k-5k-2.5k) by ROP in toluene , but the
products
did not disslove in CH2CL2 nor DMF. The solution is like semitransparent
milk,
which brought the problems to do next step. Is it normal for the
solubility?
3x |
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s****e
发帖数: 2934 | 40 ☆─────────────────────────────────────☆
fishclistoff (一切靠人品) 于 (Wed Sep 6 12:20:38 2006) 提到:
got a question when reading a paper:
"After polystryene/toluene spin-coat, it was dried for 4 days at 70 C".
Why it needs such a long baking time, any particular reasons?
A beginner for polymer, thanks for helping out.
☆─────────────────────────────────────☆
dena (dean) 于 (Wed Sep 6 20:53:41 2006) 提到:
Probably some difunctional styrenes or curing points such as epoxy group in
it so that a lon |
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s****e
发帖数: 2934 | 41 ☆─────────────────────────────────────☆
singye (温润如玉) 于 (Wed Sep 20 13:02:40 2006) 提到:
最近用一个，室温下结晶微热变成粘稠的液体的小分子作sipincoating，这个粘稠的液
体不能wet substrate，10%的溶液也不能wet substrate，用50％的浓度的溶液倒是可
以（奇怪）。解决不了在spincoating过程中后期结晶的问题。微热会使溶剂蒸发，结
果也不能wet substrate。有哪位能给点建议的？多谢了。
☆─────────────────────────────────────☆
monzonite (Monzonite) 于 (Tue Sep 26 13:40:17 2006) 提到:
MIBK has low surface energy (24 dyne/cm). Toluene is about 28, similar to
xylene. They have meidum boiling points and vapor pressure |
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s****e
发帖数: 2934 | 42 ☆─────────────────────────────────────☆
shaxixi (stupid) 于 (Mon Oct 30 08:55:49 2006) 提到:
I synthesized PLA-PEG-PLA (2.5k-5k-2.5k) by ROP in toluene , but the
products
did not disslove in CH2CL2 nor DMF. The solution is like semitransparent
milk,
which brought the problems to do next step. Is it normal for the
solubility?
3x
☆─────────────────────────────────────☆
nomos (秩序) 于 (Mon Oct 30 13:36:34 2006) 提到:
试试六氟丙酮
☆─────────────────────────────────────☆
jinlaoy (cowboy) 于 (Mon Oc |
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t********o
发帖数: 287 | 43 如果不起副作用的话，可以在溶液里滴上两滴toluene，对均匀分布很管用的。大概5毫
升加一滴，试试看。 |
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n*****e
发帖数: 19 | 44 我不是很确定这一点。我的经验是，有些样品表面上虽然干燥好了，
但是在加热抽真空的条件下，还是看到样品内部产生大量的气泡。
做了个小实验验证了一下：
取了2.307g的PS（STYRON，分子量没有去查），用toluene溶解，
在通风橱内自然蒸发一周后，用油泵在常温抽真空干燥一周，取出来
称重，得到2.620g固体，残余溶剂质量大概在10%左右。再将样品
放入真空箱，升温至Tg以上抽真空干燥。可以观察到样品内部有大量
气泡产生。取出样品后称重，得2.267g固体（质量比初始质量略小），
说明此时溶剂才完全被抽干。
为了说明问题，上面的例子取的比较极端。但是至少我不能确定对于大
多数样品，Tg以下的真空干燥是否是足够的。 |
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n***s
发帖数: 1745 | 45 不跑题，还是说这个高分子，下面是我了解到的的一些信息。
using (complex) initiator which consists of a bulky aluminum compound,
utilized in the presence of a Lewis base (polyethers, polyamine, etc.), in
Toluene from -30°C- -0°C
sec-BuLi, tert-BuLi, --- initiator.
isobutylbis(2,6-tert-butyl-4-methylphenoxy)aluminium ---- co-initiator.
2-dimethoxyethane (DME) ----- Lewis base.
PMMA含量分别为32％，或者是50％， 最终产物透明度可达91% |
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d**a
发帖数: 3715 | 46 I recently synthesized a monomer with a styrene as one functional end group
(confirmed by NMR) and try to co-polymerize this monomer with commercially
available styrene
I ran the reaction in this way:
mix my monomer A, styrene, and AIBN in tolunene
A: 0.25 g, 0.48 mmol
styrene: 0.05 g, 0.48 mmol
AIBN 0.0055 g, 0.034 mmol, 3.5 mol% of monomers.
Freeze-thaw degas twice,nitrogen purge, in 50 mL of toluene at 80 degree C,
stirring for three days.
But it came out nothing has happened. I just checked |
|
t***u
发帖数: 20182 | 47 1.need to remove the inhibitor
2.how pure is your monomer
3.toluene-chain transfer agent
4.AIBN at 80 oC has a half life of about 10min?
5.concentration too low
6.monomer to initiator ratio,like 10 to 1? |
|
d**a
发帖数: 3715 | 48 Thank you so much for your reply.
Can I purify the styrene using a silica gel column?
Yes. A is a aromatic solid compound and easy to dissolve in toluene.
Then what your suggestion for the reaction time,temperature, and the
selection of initiator?
Thanks.
A |
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d**a
发帖数: 3715 | 49 Thank you. That is what I am thinking about. Last time too much solvent (50
mL of toluene) was added into the system. So next time I will try to run the
reaction in 1 g scale and use minimal amount of solvent.
dissolved |
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d**a
发帖数: 3715 | 50 Update:
Reaction 1: polymerize styrene
After removing the inhibitor originally in styrene by passing a
chromatographic column, 5 gram of styrene were mixed with 1 mol % of AIBN in
5 mL of anhydrous THF. The reaction solution was then stirred overnight at
80 oC with a gentle nitrogen purge. In the next morning, all the THF was
found to be blew off and the entire styrene was polymerized to form one
piece of rigid clear material, which was then dissolved in hot toluene and
precipitate in cold met |
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