c*******n
发帖数: 1648 | 1 I am sure that tuning properties (not limited to surface tension) by using
copolymers has been regular practice in adhesive industry. Do you use "post
it" by 3M? That's a crosslinked acrylic copolymer, and dated back to 1970s.
http://www.sciencemag.org/cgi/content/full/308/5719/236?maxtoshow=&HITS=10&hit
s=10&RESULTFORMAT=&author1=craig+hawker&searchid=1113597928104_10041&stored_se
random |
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l***y
发帖数: 2 | 2 No new chemicals generated? Are photopolymerization and thermapolymerizatio
the physical crosslink methods? |
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b***e
发帖数: 115 | 3 crosslinking 太高,会导致材料变脆吧?? |
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c*s
发帖数: 2145 | 4 low tg, hehe
发信人: blome (standaside), 信区: Macromolecules
标 题: Re: 怎么让polymer韧性大点？
发信站: BBS 未名空间站 (Sat Jul 16 09:37:11 2005), 转信
crosslinking 太高,会导致材料变脆吧?? |
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w********h
发帖数: 12367 | 5 Tg随着crosslinking density增加而增加，
所以不可交联度太高。
另外chain flexibility (or rigidity)不仅仅体现在Tg上。。。
当然roughly，低Tg，适当的交联度是不错的。。。
另外，抗撕裂性又是另外一个story乐。。。 |
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c*******n
发帖数: 10 | 6 to be completely amorphous and in solid state, you should crosslink the chains
, just like in rubber.
You can plasticize the rubber with solvents to form gel to further reduce Tg.
Dynamics only determine what is the kuhn length, but no one can give a clear
definition of the critical DP to be called 'polymer'.
You may define a 'polymer' with DP above entanglment with typical Rouse and
Repetation behavior in G'-T (f) plot.
Or define a 'polymer' with DP above which Tg does not change with Mw.
Anywa |
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s****e
发帖数: 2934 | 7 就讨论高分子缩聚的最普通的情况。本人认为，高分子在溶液中发生crosslink之后会出
现两种情况，一种是分子量增大到不溶于溶剂的地步从而沉淀，另一种是gelation，形成
整个network。区别是后者官能团的反应速度大于前者。我的想法对吗？各位有什么高见
？ |
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s*****i
发帖数: 146 | 8 K. Weadock, R.M. Olson and F.H. Silver, Evaluation of collagen crosslinking
techniques, Biomater Med Devices Artif Organs 11 (1983–1984), pp. 293–318 |
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s****e
发帖数: 2934 | 9 你这太懒了，信息咋不给全呢？谁还给你去查杂志的全名啊。最好像scifinder一样给
信息，俺就去帮你找。
crosslinking
318 |
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d**a
发帖数: 3715 | 10 Probably some difunctional styrenes or curing points such as epoxy group in
it so that a long baking time is needed to crosslink them thermally. |
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s****e
发帖数: 2934 | 11 来自主题: Macromolecules版 - 请教 UV crosslinkable的小分子和大分子都用哪些方面的用途。 |
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s****e
发帖数: 2934 | 12 化合物都会在UV条件下crosslink吗？如果会的话，是哪段波长的UV啊？220nm以上还是
一下，好像以下就可以是吧？ |
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c*s
发帖数: 2145 | 13
Bates fundamental and insightful
Eisenberg too old
Winnik not in this field
Lodge very nice person very active, block copolymer application in materials
Wooley vrey popular and active shell-crosslink triblock and new
polymerization chem
Armes not like his style, publish like a crazy dog
Lecommandoux self-assembly of bio-macromolecules not very impressive
Guojun Liu one of the best chinese polymer physicist, but very pushy
+ manners ian
每个教授的侧重点不一样，多看看他们的代表作，卡看你自己的兴趣在什么地方， 我
也是新手，但是也见过其中几个，和其中两个 |
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P********n
发帖数: 372 | 15 弄点丙烯酸酯类的单体，加一点点光引发剂，紫外光照一下就聚合了。如果是要形成交
联结构，单体里面再混一点双官能团的单体。偶不要求引文章，给发个包子就可以，哈
哈。 |
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d**a
发帖数: 3715 | 17 The sample is crosslinked and amorphous so there is no crystalline. |
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r******0
发帖数: 2753 | 18 What do you mean "surface crosslinking"? |
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d**a
发帖数: 3715 | 19 It is normal for the surface to be hydrophobic on your amphiphilic material
because the less polar component would like to expose to non-polar air
contact interface through chain reorganization even the surface has been
crosslinked. If there is a way you can achieve the surface by contacting
with a glass slide or silicon wafer, you will find the contact angle at the
resulting substrate contact interface will much lower. High resolution XPS
will be helpful to tell the difference on the chemical |
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d**a
发帖数: 3715 | 20 请问 diacrylate 的 functionality 是4还是2.
我们实验室的postdoc认为是2，因为有两个官能团。
但是我认为是4. 因为每个acrylate可以和另外的两个acrylate反应。这也是为什么
diacrylate
能够自身crosslink 形成 network. 根据书上说的，只有 functionality >2 才可以交
联的。
请问哪位达人能够指点一下。谢谢。 |
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c****e
发帖数: 32 | 21 请问各位做hydrogel的大牛，要想让hydrogel的稳定性更好些，是不是只能用
photopolymerization或者crosslinking（比如说Michael addition）啊？
我现在做的在37 oC水中一个小时就化了，根本养不了细胞。
谢谢。 |
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z*e
发帖数: 10 | 22 F127是有些毒性。
你用的什么分子量的PEG。。。可以用alpha-cytodextrin来增强， 你可以参照一些文
献看看， 这样可以通过形成inclusion complexes，多些physical crosslinking |
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D********g
发帖数: 533 | 23 What kind of materials did you use? PEG short chain?
You can also use physical crosslinking to increase the strength of the
hydrogel, also the molecular weight (although not so efficient because of
the plateau...) |
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r******0
发帖数: 2753 | 24 when both functional groups are on the polymer chain, their mobility is
highly limited. The chance of crosslinking reaction is very low, specially
when there is BtOH is present as both reactant and solvent. |
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r******0
发帖数: 2753 | 25 The deprotection of PVAc will not be quantative for sure. And I don't think crosslinking will occur either. |
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a*i
发帖数: 1652 | 26 how about a crosslinking method that doesn't release low molecules? |
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d*******7
发帖数: 188 | 27 不知道发在这里合适不合适，但是还是希望有牛人来解答一下，我没有这方面的背景。
问题： 要测一种材料对液体的 permeability， 但是这种材料不是弹性的，而且很薄
，crosslink之后比较脆，如何能够用试验方法测呢？ diffusion cell 好像对那些有
弹性的薄膜
有用，但是我这个O-ring一夹紧会破坏材料本身.
还有一个问题是，这个材料本身是粘合剂 adhesion promoter, 很难把这层从基片上取
下来, 有没有一种可溶性的基片（而且表面很光滑的)??
有没有人做过类似材料的测试？望不吝赐教， 谢谢 |
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t*******n
发帖数: 66 | 28 Job Description
We are seeking a recent graduate student or a postdoc to synthesize well-
defined hydrogels with different crosslinking chemisty and study their
structure-property relationship to be used for the enhanced oil recovery (
EOR) of mature oil fields. Moreover, this project will involve a lot of
communication and hands-on training with other group members working on
hydrogel analysis tests such as filtration test and core-flooding tests etc
for EOR. Hydrogel based polymer flooding fo |
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t*******n
发帖数: 66 | 29 Job Description
We are seeking a recent graduate student or a postdoc to synthesize well-
defined hydrogels with different crosslinking chemisty and study their
structure-property relationship to be used for the enhanced oil recovery (
EOR) of mature oil fields. Moreover, this project will involve a lot of
communication and hands-on training with other group members working on
hydrogel analysis tests such as filtration test and core-flooding tests etc
for EOR. Hydrogel based polymer flooding for |
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m*****e
发帖数: 1506 | 30 【 以下文字转载自 Chemistry 讨论区 】
发信人: matrice (matrice), 信区: Chemistry
标 题: reference help, Thanks a lot
发信站: BBS 未名空间站 (Fri Jan 21 22:03:30 2011, 美东)
Synthesis and properties of waterborne self-crosslinkable sulfo-urethane
silanol dispersions
Journal of Polymer Science Part A: Polymer Chemistry
Volume 40, Issue 17, pages 3037–3045, 1 September 2002
please send to j*[email protected]. Thanks a lot |
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s*********a
发帖数: 13 | 31 不懂molecular imprinting 只看到很多人拿PDMS做lithography
Crosslink density很高也不行，因为PDMS是amorphous 的啊，哪来orientation 啊 |
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s**********g
发帖数: 552 | 32 gamma radiation crosslinking. Have you checked the terminal groups? |
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l*******i
发帖数: 52 | 33 As I know, HTV (high temperature valcunizing) silicone rubber use pure PDMS.
it is crosslinked with free radical mechanism under high temperature and
high pessure to form all kinds of silicone products. |
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h******t
发帖数: 3858 | 34 GPC, MALDI貌似都只能告诉分子量吧？
小白一枚，请大牛们不吝赐教！ |
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t******y
发帖数: 1616 | 37 DSC？
hyperbranch如果够大的话，比如PAMMA G4G5那样大小 可做cryoEM |
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h******t
发帖数: 3858 | 38 GPC, MALDI貌似都只能告诉分子量吧？
小白一枚，请大牛们不吝赐教！ |
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t******y
发帖数: 1616 | 41 DSC？
hyperbranch如果够大的话，比如PAMMA G4G5那样大小 可做cryoEM |
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P********n
发帖数: 372 | 42 ls的意思是说既然什么都不溶解，直接证明是交联了。还用做别的干啥？ |
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r******t
发帖数: 8967 | 45 manual上是95度，如果降到70～80度，延长时间，行不行？ |
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P******e
发帖数: 344 | 46 Cree Interveiw Experience
Glassdoor上是说很变态的。实际上也就是Tough了一点。
Phone Interview 等于啥都没问。
On site interview 旅途糟糕透顶，前一个晚上就睡了2个小时。
再前前一个晚上睡了4个小时，所以面试当天状态很差。
下面是我的记录
1. presentation
list all the details, audience can read from what you put on,
you do not need read every thing presented.
a big picture, balance between previous and present
details, direct details, easy to understand
everything list should cause no problem, and understand all
objective clear, whys,
2. 1-1 interview
prepare questi... 阅读全帖 |
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M********r
发帖数: 179 | 47 来自主题: MedicalCareer版 - 药理的复习 谢谢你的回复，我会试试看的。我也在查找材料，有人提到用FLASH CARD，是不是也是
个增强CROSSLINK的好办法呢？
我用的是下载版，前面有人好像贴过的，我的是用电驴下的。 |
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l*********p
发帖数: 197 | 48 在acrylate polymer的表面通过michael addition反应上一层amine,
如何知道amine的数目???
别人说可以用XPS来测,但不是很清楚怎么测
还有,有没有其他的办法啊?
polymer是用acrylate的monomer crosslink出来的,
是不是也没法通过monomer的量来计算啊?
谢谢了. |
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a*****u
发帖数: 4 | 50 求文献（J. Nanosci. Nanotechnol. 2008, 8, 6283-6289）
Incorporation of Gold Nanoparticles Within Thermoresponsive Microgel
Particles: Effect of Crosslinking Density
http://www.aspbs.com/jnn/
多谢，E-mail: z****[email protected] |
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