n******g
发帖数: 662 | 1 ZnO has a high solubility in water because it reacts with water. Many
reported papers mentioned this property, but several published papers in
some journals state their ZnO NPs can directly conjugated with proteins for
labeling or imaging. |
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y*****s
发帖数: 1047 | 2 广告都多得很
Posted/Revised: 5/2/2012
Company/Institute: Pfizer Inc
Department:
Position: 2 Year Postdoctoral Fellow – Protein Quantitation in Tissues
by Mass Spectr
Job Location: Andover, MA United States
Description: 2 year Postdoctoral Fellow – Protein Quantitation in
Tissues by Mass Spectrometry and Immunoanalytical Techniques A Postdoctoral
Fellowship is available in Pfizer’s Pharmacokinetics Dynamics and
Metabolism New Biological Entities (PDM-NBE) in Andover, MA. The PDM ... 阅读全帖 |
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S*****n
发帖数: 6055 | 3 it depends
there are occations that gas could have higher solubility
for example, hydride formation
another example, MOF
子形式溶解)，我觉 |
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N********2
发帖数: 9 | 4 Dietary supplements in food science is called functional foods,functional
ingredients (additives) or foods with health benefits. Certainly, additives
can also be fortified/encapsulated flavors, colors, and enzymes. For a
polymer chemist, there are a lot of demands for people who have strong
background in natural biopolymers, esp. modification and their functional
properties, which is also a part of 功能高分子。Dietary supplements involve
a lot of formulations to improve their water solubility, biocomp... 阅读全帖 |
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hr
发帖数: 247 | 5 It seems high vacuum pump still can not completely remove it. And our target
compound is also soluble in water. Thanks! |
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C********g
发帖数: 211 | 6 Journal of nanoscience and nanotechnology: 2006, 6(8), 2461
Determination of the size of water-soluble nanoparticles and quantum dots by
field-flow fractionation
Thanks so much! |
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l*****g
发帖数: 556 | 7 urethane? FTIR has CRC library (or vendor such as Thermo has its own
library).
But if it's soluble in CDCl3, why not NMR? Only $50 or so per sample. |
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i*n
发帖数: 9793 | 8 [3] K Kannan, M.G Mulkerrin, M Zhang, R Gray, T Steinharter, K Sewerin, R
Baffi, R
Harris, C Karunatilake , Rapid analytical tryptic mapping of a recombinant
chimeric monoclonal antibody and method validation challenges , Journal of
Pharmaceutical and Biomedical Analysis, Volume 16, Issue 4, December 1997,
Pages 631-640
[7]Dai W.G, Dong L.C, Song Y.Q, Nanosizing of a drug/carrageenan complex to
increase solubility and dissolution rate, Int. J. Pharm. 342 (2007) 201-207.
[10]Cohen R, Orlova Y, Ko... 阅读全帖 |
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q****i
发帖数: 6923 | 9 Preparation of almost dispersant-free colloidal silica with superb
dispersibility in organic solvents and monomers
Journal of Nanoparticle Research (2011), 13, (9), 3885-3897. Publisher: (
Springer, ) CODEN:JNARFA ISSN:1388-0764.
Effect of organic solvents on the preparation of silica microspheres by
hydrolysis of TEOS
Xiyou Jinshu Cailiao Yu Gongcheng (2007), 36, (Suppl. 1), 180-183.
Surface modification of colloidal silica particles
Colloid and Polymer Science (2001), 279, (2), 114-121.
Solubi... 阅读全帖 |
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f****n
发帖数: 95 | 10 我在为含氟的丙烯酸酯/丙烯酰胺类高分子寻找good solvent,发现trifluoroacetic
acid (TFA)的溶解能力特别强，很好用。可是，高分子（白色粉末）溶解于新鲜的TFA
之后溶液由无色透明慢慢变为淡黄色透明。
是不是因为TFA是强酸有所谓的发烟现象？浓盐酸就是淡黄色，因为含有少量杂质Cl2
。另外， 含卤素或含硝基的化合物容易变颜色,是少量变质导致的吗？
谢谢！
p.s.
查到有这么一句：“olutions of proteins in trifluoroacetic acid prepared in
vacuo
are clear and colourless; on exposure to air, a purple colour develops.”不
解中···
Nature 174, 509 (11 September 1954); doi:10.1038/174509a0
Anhydrous Trifluoroacetic Acid as a Solvent for Proteins
JOSEPH J. KATZ
Chemistry Di... 阅读全帖 |
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i*n
发帖数: 9793 | 11 1. K. Bielicka-Daszkiewicz, A. Voelkel, M. Pietrzyńska, K. Heberger, Role o
f Hansen solubility parameters in solid phase extraction, J. Chromatogr. A,
1215 (2010) 5564-5570.
2.J. Poerschmann, J. Microcolumn Separations 12 (2000) 603-612
3.Voelkel, A. ,Strzemiecka, B., Adamska, K.,Milczewska, K. Inverse gas
chromatography as 316 a source of physiochemical data, Journal of
Chromatography A, 1216 (2009)1551–1566
Thanks! |
|
D***1
发帖数: 200 | 12 We are hiring Scientist with Life Technologies at Bedford, MA.
The project is budgeted for 1 Year to start and possibility of further
extension.
Description: Research Chemist with experience and demonstrated aptitude in
organic synthesis and surface chemistry to support new product development
and program feasibility projects. Supported programs will primarily focus on
immunoassay detection and surface chemistry platforms for research and
diagnostics applications.
Working as part of small, but d... 阅读全帖 |
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y***o
发帖数: 416 | 13 我来试试：
A) Identify the types of plastic resin based on the appearance and the
combustion characteristics of plastic materials, e.g. PP, PE, PVC, ABS, PET,
PS, PC, PMMA, PVB, etc.
B) Determine the grade and use of the identified type of plastic resin, such
as injection molding, extrusion, drawing, blow molding etc., and give
recommendations of target customers based on the material properties.
C) Develop an appropriate sorting strategy for mixed plastic resins
according to the density differences.... 阅读全帖 |
|
|
c******6
发帖数: 928 | 15 "Insight into the Binding Modes and Inhibition Mechanisms of Adamantyl-based
1,3-disubstituted Urea Inhibitors in the Active Site of the Human Soluble
Epoxide Hydrolase", J. Biomol Struct & Dyn, 31(8)(2014)1231-1247. |
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x**1
发帖数: 106 | 16 A post-doctoral position funded by NIH is available for a highly motivated
individual. The candidate should have strong synthetic organic chemistry
background. Research in the Liu lab encompasses a broad spectrum of
synthetic chemistry and methodology to prepare highly water-soluble near-
infrared fluorescent probes for insightful understanding of cellular
functions. Qualified candidates should have a PhD in organic chemistry and
be well grounded in analytical techniques. The candidate must ... 阅读全帖 |
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q****i
发帖数: 6923 | 17 Self-Assembly and Cellular Uptake of Degradable and Water-Soluble
Polyperoxides
Tamami Fujioka, Shuji Taketani, Takeshi Nagasaki and Akikazu Matsumoto
Bioconjugate Chem., 2009, 20 (10), pp 1879–1887
http://pubs.acs.org/doi/abs/10.1021/bc9001618
Regiospecific Structure, Degradation, and Functionalization of Polyperoxides
Prepared from Sorbic Acid Derivatives with Oxygen
Yuko Sugimoto Shuji Taketani Tomoaki Kitamura Daisaku Uda Akikazu Matsumoto
Macromolecules, 2006, 39 (26), pp 9112–9119
http://p... 阅读全帖 |
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P********n
发帖数: 372 | 18 Title: Laboratory Technician/Chemist
Location: Houston TX, 77082
Job Summary:
· The technical service /development chemist will provide hands-on
laboratory support to solve various customer problems and generate
innovative technical solutions that support current business and generate
new business growth opportunities
Specific duties include:
· Assisting in the technical transfer of new technology/product and
technical service request for a Global Key Account
· Conducting... 阅读全帖 |
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e***s
发帖数: 9 | 19 这些划分都无助回答什么才是不良, 和良溶剂.
常见的判据就是solubility paparmeter是否match.
但是对有氢键或其他强相互作用的溶剂不能用.
good |
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b**s
发帖数: 589 | 20 The property most commonly relied upon to answer this question is solubility
behavior. Homopolymer blends and copolymers respond to extraction with
selective solvents and to solvent-nonsolvent fractionating techniques such as
fractional precipitation, column fractionating, and turbidometric situations.
These methods are simple and reasonably effective, particularly with systems
containing segments that differ significantly in their chemical structure
and/or physical state, e.g., polar-nonpolar |
|
b**s
发帖数: 589 | 21
不太同意， 一般看高分子结构亲水还是憎水只看侧链。
一般高分子的链段包括主链和侧链，不能拆分来看。
-(CH2-CH)- 我门就可以说这个高分子链节是极性，不能看做碳主链为非极性基团
| 因为Cl给(?)电子，所以整个链节都呈极性
Cl
实际上还是跟偶极dielectric有关，更确切的说与氢键有关，再确切一点是与熵，焓热
力学有关
水是高极性的分子，有很高的dipole moment，靠氢键把自己连再一起，这就是H2O是液
体,而H2S是气体的原因
我认为hydrophilic就是与水能interact，以至于将水分子分开，而氢键是很强的键，
所以我想可能只有能与水形成氢键的才能做到这一点。你提到的羧基，羟基，磺酸基都是
能与水形成氢键
当然从热力学分析，就是如果这个侧链基团与水miscible, 就可以将高分子也带到水
中，我们就说这个高分子是hydrophilic（solubility parameter在这里可能会有用）
ΔG<0, ΔS肯定>0, 只有靠ΔH来完成，也就是集团与水的interaction
物 |
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b**s
发帖数: 589 | 22 我觉得应该选择一种common solvent 给DMAEMA和VDF这两个基团。这种溶剂对两个链段
都non-selective就好了。或者用混合溶剂掺着用，一种可以溶DMAEMA，一种可以溶VDF，
而这两种溶剂又能互溶（solubility parameter 相近）。好像得多试验几个，然后根据
浊点法做个相图出来。
我现在也在做类似的实验。
另外加加热怎么样？ |
|
e****d
发帖数: 16 | 23 I am a new member here. And have a problem to ask for help.
我合成了一种聚合物， 合成过程中出现了爬杆包轴的现象，不溶。如何表征以证明发生
了交联？只有DSC一种方法么？ 谢谢。
I have synthesized an unsoluble polymer. During the polyerization, it showed
to be crosslinked. How can I make charaterization of it to confirm it has been
crosslinked? Is DSC the unique way?
If I change the reaction conditions, a soluble polymer can be obtained.
Thanks. |
|
e****d
发帖数: 16 | 24
can we say the polymer is crosslinked if the polymer is neither soluble nor
meltable?
PS: i am working on Polymer Science. :) |
|
b**s
发帖数: 589 | 25 Poly(methacrylic acid)
Poly(acrylic acid)
I guess
because DMF and DMSO are both their good solvents
I think you might calculate th solubility parameters of solvent and polymer,
make sure they match.
check out http://www.polysciences.com/ you will get some polymer standard
information |
|
c*s
发帖数: 2145 | 26 ? since I noticed that there are lots of papers about this topic in top
journals like JACS. |
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t*******n
发帖数: 66 | 27 I want to make a tetraacid( the solubility is very poor) to react with some
amine to form the amide. I want to use the ethyl chloroformate to activate the
acid group first and then use the amine to reacte with teh activated acid to
get the amide. While I can not get very high conversion with the first
activation step.(according to the lietrature this activation proecess should
be relatively easy). Could anyone gvie me some advie on this reaction or gvie
me some help on the convient way to form |
|
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 |
|
c****n
发帖数: 134 | 29 no.
I used both poly(tert-butyl vinyl ether) and poly(tert-butyldimethylsilyl
vinyl
ether) as precursors to pva, since living polymerization of Poly(vinyl
acetate) is not easy. (I need to prepare polymers with low PDI).
the samples are soluble in DMSO at room temp.
but refluxing water failed to dissolve them.
PVA |
|
c****n
发帖数: 134 | 30 I can actually design the MW of each segment,
The DPn of homo-PVA I used was 380, and it was soluble in water.
BTW, the PVA I prepared has a narrow PDI(<1.1) and 51% isotacticity.
the
because
vinyl
of |
|
a***n
发帖数: 578 | 31
dissolves
PIB
work
additional
of
No. what I meant was after you get rid of DMSO from your polymer, the polymer
will be soluble in water again. Anyway, just a guess. if wrong, then forget
it.
interesting
not.
range
said
hydrogen |
|
c****n
发帖数: 134 | 32 I just tested your idea. The sample is PIB(DP=50)-b-PVA(DP=200).
The sample was dissolved in DMSO. Then 10 times of water was added (the
solution became very hot in the beginning, hehe).
It remained homogeneous. So you are right :) The DMSO functions to break the
intramolecular H-bonding of PIB-b-PVA, but water is too weak to work in the
same way. Water can only break the H-bonding of homoPVA. Once the H-bonding of
PIB-b-PVA is broken, the sample is readily soluble in water.
Now the problem is: |
|
r******0
发帖数: 2753 | 33
would
~~~~~~~~~~~~~ paper on Science or a scientific
paper?
~~~~~~~~~~~~~~~ control release? Hope not.
the
the
H-bonding
soluble
hydrogen |
|
c*s
发帖数: 2145 | 34 if it is water soluble and contains dense electrolyte, it could work as PE,
my 2 cent |
|
|
m**l
发帖数: 15 | 36 If a polymer has a high Tg, say 150, is it going to be insoluble at room
temperature or are these two factors irrelavent?
Thanks! |
|
|
b**s
发帖数: 589 | 38 1. Aqueous formula, can incorporate soluble protein
2. Can deposit in open air.
3. Solidify instantly under room temperature, can support upper layer
4. No organic solvent used, no heating, no UV light
5. 100 micron feature size
6. Can make heterogeneous scaffold structure (forget about MIT's 3D printer)
7. Temporal, spatial, compositioanl and mechanical controllable in 3D pattern.
I have developed a ink satisfies all the requirments, that's the reason my
company hire me, top secret, haha.
s |
|
b*o
发帖数: 47 | 39 It means the concentration build up in the accepto chamer has little effect on
the releasing kinetic - this usually means the drug solubility is really high
or there is means to remove the released drug from the accepting chamber. I
think.
在 cxw (cxw) 的大作中提到: 】
satisfy |
|
c*s
发帖数: 2145 | 40 quantum dot, CdTe or CdS@CdSe, The reported quantum yield could be as high as
85%.
If these particles could be proved stable against o\photo or some chemical
enviroment, the results will be significant. |
|
c****n
发帖数: 134 | 41 来自主题: Macromolecules版 - 问个傻问题 1. if homopolymers and copolymer have different solubilities, you may try
separation by extraction.
2. if it is copolymer instead of homopolymer mixture, MW should be higher
3. new NMR peak could arise for copolymer, attributable to groups connecting
two monomer units. |
|
p******s
发帖数: 137 | 42 来自主题: Macromolecules版 - 问个傻问题 thanks, guys.
answer:
1. Yes, I thought of this.
However, it can get rid of only one homopolymer because I believe both
copolymer and another homo have similar solubility in organic solvent.
2. Mw is not necessarily larger because A component can react with itself;
B can react with it self too.
3. I said 端基影响不大. |
|
y***e
发帖数: 6082 | 43 USM is very famous for industry, especially for organic coating, so job-huntin
g is very easy, three guys graduated from our group got a lot good offers, suc
h as Johnson, GE, Roman Hoss, Dow; Actually academic is a little weak, McCormi
ck is good for water-soluble polymer, Mauritz is good for Nafion, Hoyle is goo
d for photopolymerization (he is a very very very nice prof, just like a father
who will care his students very much even you are not in his group for everyth
ing such as recommendatio |
|
B****W
发帖数: 100 | 44 It's easy to be synthesized, but hard to be characterized. the polymer is not
soluble in common GPC solvent. I need to titrate the endgroups to get the MW,
and usually it's not accurate. So just try to save some time and trouble :) |
|
r******0
发帖数: 2753 | 45 Does anyone know any vendors I can buy polymers from, except Aldrich and Scien
tific Polymers? Thanks. I need buy some polyacrylates copolymer with cations on side chains but the copolymer cannot be water-soluble. :) |
|
b*******n
发帖数: 29 | 46 I think the way polymer dispersing in water is very different
from the way water dispersing in polymer, e.g., water aggregates
then coalesces, which forms very good spherical structure. However,
Non-water soluble polymer in water tends to aggregates, but is hard to
coalesce, which forms a fractal structure.
This is only my GUESS.
negtive |
|
s*****i
发帖数: 146 | 47 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 |
|
j*****y
发帖数: 2 | 48
for DCM, you need to dilute, let's say, try dissolve them in 50ml of DCM
gram by gram with vigorous stirring. It may be time-consuming, however, that
's the efficient way to try solubility of macromolecules.good luck |
|
s****e
发帖数: 2934 | 49 ☆─────────────────────────────────────☆
cds (红毛呼呼猪) 于 (Sun Oct 1 23:40:38 2006) 提到:
thanks a lot. BUt my case is kinda special. it is PEG-PtBA, as u know, PtBA
can be dissolved in almost all solvents except water. therefore, the
solubility property of the block polymer is quite similar to homopolymer.
what I am trying to do is to precipitate PEG in MeOH using ether, while
keeping the block polymer micelles in MeOH. This looks viable but I am not
sure this is the best combination or not in |
|
s****e
发帖数: 2934 | 50 ☆─────────────────────────────────────☆
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 |
|
